@@ -1,48 +1,26 @@
1use std::collections::{HashMap, HashSet};
1use std::collections::{HashMap, HashSet};
3use std::path::{Path, PathBuf};
2use std::path::{Path, PathBuf};
5use crate::ast::*;
5use crate::ast::*;
6−use crate::syntax::{self, Syntax};
6+use crate::diagnostic::code;
7+pub use crate::diagnostic::{Diagnostic, Severity};
8+use crate::interp::{self, Sink};
9+use crate::syntax::{self, DirectiveArgs, LetForm, NodeKind, Segment, Tree};
10+use crate::value::{self, Value};
8// ---------------------------------------------------------------------------
12// ---------------------------------------------------------------------------
9// Public types
13// Public types
10// ---------------------------------------------------------------------------
14// ---------------------------------------------------------------------------
12−#[derive(Debug, Clone, Copy, PartialEq, Eq)]
20−#[derive(Debug, Clone)]
21−pub struct Diagnostic {
23− pub column: Option<usize>,
25− pub severity: Severity,
26− pub source_line: Option<String>,
29pub struct ParseResult {
16pub struct ParseResult {
30 pub document: Document,
17 pub document: Document,
31 pub diagnostics: Vec<Diagnostic>,
18 pub diagnostics: Vec<Diagnostic>,
32 pub included_files: Vec<PathBuf>,
19 pub included_files: Vec<PathBuf>,
35−#[derive(Debug)]
22+/// An error that stops one line from being evaluated.
36−struct ParseError {
23+type ParseError = Diagnostic;
41−impl fmt::Display for ParseError {
42− fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
43− write!(f, "line {}: {}", self.line, self.message)
47// ---------------------------------------------------------------------------
25// ---------------------------------------------------------------------------
48// Internal types
26// Internal types
@@ -50,27 +28,166 @@ impl fmt::Display for ParseError {
51#[derive(Clone)]
29#[derive(Clone)]
52struct FnDef {
30struct FnDef {
53− params: Vec<String>,
31+ /// The parameters in the order they are declared; one without a
54− defaults: HashMap<String, String>,
32+ /// default is required.
55− body: Vec<Syntax>,
33+ params: Vec<syntax::Param>,
34+ /// The definition's line and its text (when it is one physical line),
35+ /// and its node, for diagnostics about a default.
37+ source: Option<String>,
39+ body: Vec<syntax::Node>,
40+ /// The file it is defined in, when that isn't the file being compiled
41+ /// (see `ParseContext::current_file`).
42+ file: Option<String>,
43+ /// The slots its body declares (`@slot NAME`), in order.
45+ /// Whether its body has a `@children` for the content of a call.
47+ /// Its scoped `@style`, nested under its `.hl-fn-NAME` class: written
48+ /// into the page once the function is called (see
49+ /// `Document::scoped_css`).
50+ scoped: Option<String>,
51+ /// What was visible where it was defined: its body and its defaults
52+ /// see this, plus its parameters.
54+ /// It is named like a built-in element and its body calls that name
55+ /// outside any `@if`, meaning the element (`@let @nav` around `@nav`):
56+ /// it would call itself forever, so a call writes nothing (the
57+ /// definition's error says so).
62+ fn is_param(&self, name: &str) -> bool {
63+ self.params.iter().any(|p| p.name == name)
67+/// What a name means: every `@let`, parameter, loop variable and `@data`
68+/// binds one, and they share one namespace.
72+ Bundle(Rc<Vec<Attribute>>),
76+/// The names visible at a line: one frame per block it is in (the
77+/// standard library, the file, an element's children, an `@if` branch, an
78+/// iteration of `@each`, a function's body), the innermost last. A
79+/// definition goes into the innermost frame, so it is visible from its
80+/// line to the end of its block. A function keeps the frames visible
81+/// where it is defined; a frame is shared until one side changes it.
82+#[derive(Clone, Default)]
84+ frames: Vec<Rc<HashMap<String, Binding>>>,
89+ self.frames.push(Rc::default());
96+ /// Give `name` a meaning in the innermost frame, replacing what it
97+ /// meant there and hiding what it means outside it.
98+ fn define(&mut self, name: &str, binding: Binding) {
99+ if self.frames.is_empty() {
102+ if let Some(frame) = self.frames.last_mut() {
103+ Rc::make_mut(frame).insert(name.to_string(), binding);
107+ /// What `name` means here: the innermost definition.
108+ fn get(&self, name: &str) -> Option<&Binding> {
109+ self.frames.iter().rev().find_map(|frame| frame.get(name))
112+ fn value(&self, name: &str) -> Option<&Value> {
113+ match self.get(name)? {
114+ Binding::Value(value) => Some(value),
119+ fn bundle(&self, name: &str) -> Option<&Rc<Vec<Attribute>>> {
120+ match self.get(name)? {
121+ Binding::Bundle(attrs) => Some(attrs),
126+ fn function(&self, name: &str) -> Option<&Rc<FnDef>> {
127+ match self.get(name)? {
128+ Binding::Function(function) => Some(function),
133+ /// Every name visible here, with what it means.
134+ fn visible(&self) -> HashMap<&str, &Binding> {
135+ let mut names = HashMap::new();
136+ for frame in &self.frames {
137+ for (name, binding) in frame.iter() {
138+ names.insert(name.as_str(), binding);
144+ /// The names of the values visible here.
145+ fn value_names(&self) -> Vec<&str> {
148+ .filter(|(_, binding)| matches!(binding, Binding::Value(_)))
149+ .map(|(name, _)| name)
153+ /// The names of the bundles visible here.
154+ fn bundle_names(&self) -> Vec<&str> {
157+ .filter(|(_, binding)| matches!(binding, Binding::Bundle(_)))
158+ .map(|(name, _)| name)
163+impl interp::Scope for Env {
164+ fn get(&self, name: &str) -> Option<Value> {
165+ self.value(name).cloned()
58struct ParseContext {
169struct ParseContext {
59 /// Source line currently being parsed, for diagnostics raised deep
170 /// Source line currently being parsed, for diagnostics raised deep
60 /// inside helpers that don't take a line number.
171 /// inside helpers that don't take a line number.
61 current_line: usize,
172 current_line: usize,
62− /// Functions whose body has a scoped @style block.
173+ /// What the `@page` said, once one has run
63− scoped_functions: std::collections::HashSet<String>,
174+ page: Option<Page>,
64− page_title: Option<String>,
175+ /// Where that `@page` is, for the error a second one gets
65− lang: Option<String>,
176+ page_at: Option<String>,
66− favicon: Option<String>,
67 meta_tags: Vec<(String, String)>,
177 meta_tags: Vec<(String, String)>,
68 head_blocks: Vec<String>,
178 head_blocks: Vec<String>,
69− variables: HashMap<String, String>,
179+ /// The first `@meta` or `@head` that ran, for the warning a file
70− defines: HashMap<String, Vec<Attribute>>,
180+ /// without `@page` gets: a fragment has no `<head>` for them.
71− functions: HashMap<String, FnDef>,
181+ head_at: Option<usize>,
182+ /// What each name means at the line being evaluated.
184+ /// Every function whose definition ran, by name (the last one), for
185+ /// the checks of code that never runs.
186+ defined_functions: HashMap<String, Rc<FnDef>>,
72 css_vars: Vec<(String, String)>,
187 css_vars: Vec<(String, String)>,
73 custom_css: Vec<String>,
188 custom_css: Vec<String>,
189+ /// The scoped `@style` of each function called so far
190+ scoped_css: Vec<String>,
74 og_tags: Vec<(String, String)>,
191 og_tags: Vec<(String, String)>,
75 diagnostics: Vec<Diagnostic>,
192 diagnostics: Vec<Diagnostic>,
76 base_path: Option<PathBuf>,
193 base_path: Option<PathBuf>,
@@ -90,35 +207,550 @@ struct ParseContext {
90 fn_lines: HashMap<String, usize>,
207 fn_lines: HashMap<String, usize>,
91 /// Line numbers of attribute bundle definitions (name -> line)
208 /// Line numbers of attribute bundle definitions (name -> line)
92 define_lines: HashMap<String, usize>,
209 define_lines: HashMap<String, usize>,
210+ /// Syntax nodes evaluated at least once, by id.
211+ visited: HashSet<usize>,
212+ /// The id the next parsed tree starts at, so ids are unique across
213+ /// the file, its includes and the standard library.
215+ /// The file's tree and those of the files it includes, with the
216+ /// include chain that leads to each, for the checks of code that never
218+ trees: Vec<(Rc<Tree>, Option<String>)>,
219+ /// The files each `@include` line brought in (by the line's node id),
220+ /// with the include chain that leads to each, so the checks of
221+ /// `@slot` and `@children` see an included file's lines where the
222+ /// `@include` is written.
223+ included_by: Rc<IncludedBy>,
224+ /// Every function defined anywhere in the file or the files it
225+ /// includes, whether or not its definition runs.
226+ namespace: HashSet<String>,
227+ /// The line being evaluated, and its text as written when it is one
228+ /// physical line, for diagnostics that point at a column.
229+ current_source: (usize, Option<String>),
230+ /// Variable diagnostics already reported, so a line evaluated many
231+ /// times (in a loop, in a function) reports each problem once.
232+ /// Keyed by the syntax node (ids are unique across files), line,
233+ /// column and message.
234+ reported: HashSet<(usize, usize, Option<usize>, String)>,
235+ /// The id of the syntax node being evaluated.
236+ current_node: usize,
237+ /// The file whose lines are being evaluated, when it isn't the file
238+ /// being compiled: the standard library, or an included file (by its
240+ current_file: Option<String>,
241+ /// A call went deeper than [`MAX_CALL_DEPTH`]: the calls it is nested
242+ /// in expand to nothing, until the outermost one returns.
244+ /// A bundle's attributes are being read: a name that could be a
245+ /// parameter of the function the bundle is passed to is checked where
246+ /// the bundle is used instead.
248+ /// `@page`'s attributes are being read: a name close to `favicon` is
249+ /// a misspelled word of `@page`'s.
253+/// How deeply function calls may nest, so that a function that calls
254+/// itself without an `@if` that stops it is an error instead of a hang.
255+const MAX_CALL_DEPTH: usize = 64;
257+/// A CSS rule at the top level of a stylesheet that starts with `&`
258+/// (outside any `{}`, strings and comments).
259+fn has_top_level_ampersand(css: &str) -> bool {
260+ let mut depth = 0usize;
261+ let mut chars = css.chars().peekable();
262+ let mut at_rule_start = true;
263+ while let Some(c) = chars.next() {
265+ '/' if chars.peek() == Some(&'*') => {
268+ for c in chars.by_ref() {
269+ if last == '*' && c == '/' {
277+ for d in chars.by_ref() {
284+ '}' => depth = depth.saturating_sub(1),
285+ '&' if depth == 0 && at_rule_start => return true,
288+ at_rule_start = match c {
289+ '{' | '}' | ';' => true,
290+ c if c.is_whitespace() => at_rule_start,
297+/// Whether a file is a library (see [`Tree::is_library`]), with the files
298+/// its `@include` lines name read relative to `base`.
301+ base: Option<&Path>,
302+ ctx: &mut ParseContext,
303+ seen: &mut Vec<PathBuf>,
305+ tree.is_library_with(&mut |path| {
306+ if path.contains('$') {
309+ let resolved = base.map_or_else(|| PathBuf::from(path), |base| base.join(path));
310+ if seen.contains(&resolved) {
313+ seen.push(resolved.clone());
314+ let Ok(text) = ctx.read_file(&resolved) else {
317+ let included = syntax::parse(&text);
318+ is_library_file(&included, resolved.parent(), ctx, seen)
322+/// The frames around the file's top level: the standard library's and
323+/// the file's own (see [`load_prelude`]).
324+const FILE_FRAMES: usize = 2;
95/// Evaluates a syntax tree (see `syntax.rs`) into the document's nodes.
326/// Evaluates a syntax tree (see `syntax.rs`) into the document's nodes.
96struct Evaluator;
327struct Evaluator;
98impl ParseContext {
329impl ParseContext {
99− /// Evaluate an expression (see `expr.rs`), reporting errors at `line`.
330+ /// Bind a value to `name` in the innermost block.
100− fn eval(&mut self, src: &str, line: usize) -> Option<crate::expr::Value> {
331+ fn bind(&mut self, name: &str, value: Value) {
332+ self.env.define(name, Binding::Value(value));
335+ /// Evaluate an expression (see `expr.rs`) written at `line` and
336+ /// `column` (when known), reporting its errors there.
341+ column: Option<usize>,
342+ ) -> Option<crate::expr::Value> {
101 track_var_refs(src, &mut self.used_variables);
343 track_var_refs(src, &mut self.used_variables);
102− let vars = &self.variables;
344+ match crate::expr::eval(src, &self.env) {
103− let result = crate::expr::eval(src, &|name: &str| lookup(vars, name));
105 Ok(value) => Some(value),
345 Ok(value) => Some(value),
106− Err(message) => {
346+ Err(error) => {
107− self.diagnostics.push(Diagnostic {
347+ // Without the line to point into, show the expression
108− line,
348+ let shown = matches!(&self.current_source, (current, Some(_)) if *current == line);
109− column: None,
349+ let before = self.diagnostics.len();
110− message: format!("invalid expression: {}", message),
350+ self.report(error.at(0), line, column);
111− severity: Severity::Error,
351+ if !shown && let Some(diagnostic) = self.diagnostics.get_mut(before) {
112− source_line: Some(src.to_string()),
352+ diagnostic.source_line = Some(src.into());
119 /// Evaluate a condition; an invalid one is reported and counts as false.
359 /// Evaluate a condition; an invalid one is reported and counts as false.
120− fn condition(&mut self, src: &str, line: usize) -> bool {
360+ fn condition(&mut self, src: &str, line: usize, column: Option<usize>) -> bool {
121− self.eval(src, line).is_some_and(|value| value.truthy())
361+ self.eval(src, line, column)
362+ .is_some_and(|value| value.truthy())
365+ /// Fill in one slot of htmlang text written at `line` and `column`
366+ /// (when known), for `sink`: its escapes stand for themselves and its
367+ /// variables are filled in (see `interp.rs`). What can't be filled is
368+ /// left as written and reported; the flag says whether everything was
374+ column: Option<usize>,
376+ ) -> (String, bool) {
377+ let (filled, ok) = self.fill_protected(raw, line, column, sink);
378+ (restore_escapes(&filled), ok)
381+ /// [`fill`](Self::fill) for text.
382+ fn interpolate_text(&mut self, raw: &str, line: usize, column: Option<usize>) -> String {
383+ self.fill(raw, line, column, Sink::Text).0
386+ /// [`fill`](Self::fill), with the escapes still placeholders (see
387+ /// [`protect_escapes`]).
392+ column: Option<usize>,
394+ ) -> (String, bool) {
395+ let mut protected = protect_escapes(raw);
396+ if sink == Sink::Css {
397+ protected = keep_css_string_escapes(&protected);
399+ if !protected.contains('$') {
400+ return (protected, true);
402+ track_var_refs(&protected, &mut self.used_variables);
403+ let (out, problems) = interp::interpolate_for(&protected, &self.env, sink);
404+ let filled = problems.is_empty();
405+ for mut problem in problems {
406+ match &mut problem {
407+ interp::Problem::Undefined { offset, .. }
408+ | interp::Problem::CustomProperty { offset, .. }
409+ | interp::Problem::Invalid { offset, .. }
410+ | interp::Problem::Record { offset, .. } => {
411+ // An offset into the protected text, as one into `raw`
412+ *offset = protected[..*offset]
414+ .map(|c| escape_of(c).map_or(c.len_utf8(), str::len))
418+ self.report(problem, line, column);
423+ /// Fill in a value slot (an attribute's value, a `@let` value, `@meta`'s
424+ /// value) for `sink`, and say whether it is quoted text: one `"..."`, or
425+ /// one variable that holds quoted text. Quoted text keeps its quotes
431+ column: Option<usize>,
433+ ) -> (String, Option<Quoted>, bool) {
434+ if let Some(inner) = syntax::quoted_string(raw) {
435+ let (css, ok) = self.fill(raw, line, column, Sink::Css);
436+ // Already reported by the CSS pass, so filled in quietly
437+ let (text, _) = interp::interpolate(&protect_escapes(inner), &self.env);
438+ let quoted = Quoted {
439+ text: restore_escapes(&text),
442+ let out = match sink {
443+ Sink::Css => quoted.css.clone(),
444+ Sink::Text => quoted.text.clone(),
446+ return (out, Some(quoted), ok);
448+ let (out, ok) = self.fill(raw, line, column, sink);
449+ let quoted = whole_reference(raw, &self.env).and_then(|path| {
450+ match interp::resolve(&path, &self.env)? {
451+ Value::Quoted(quoted) => Some(quoted),
458+ /// The value of a value slot (a `@let` value, the source of `@each`, a
459+ /// parameter's value or default), written at `line` and `column`:
461+ /// - exactly one `$name` or `${...}` is the value it holds or gives,
462+ /// whatever its type (a list, a record, quoted text);
463+ /// - one `"..."` is quoted text;
464+ /// - commas outside quotes, brackets and `${...}`, and not escaped
465+ /// (`\,`), make a list, which prints as written;
466+ /// - `A..B` or `A..B step N` with whole numbers is a range;
467+ /// - anything else is text, with its variables filled in.
469+ /// What can't be filled in is reported; the flag says whether
471+ fn slot_value(&mut self, raw: &str, line: usize, column: Option<usize>) -> (Value, bool) {
472+ let trimmed = raw.trim();
473+ let column = column.map(|c| c + (raw.len() - raw.trim_start().len()));
474+ if let Some(value) = self.whole_value(trimmed, line, column) {
477+ if syntax::quoted_string(trimmed).is_some() {
478+ let (text, quoted, ok) = self.fill_value(trimmed, line, column, Sink::Text);
479+ return (quoted.map_or(Value::Str(text), Value::Quoted), ok);
481+ let parts = syntax::split_list(trimmed);
482+ if parts.len() > 1 {
483+ // Each item is a value of its own; the list prints as written
484+ let mut items = Vec::new();
485+ let mut written = String::new();
489+ let item = &trimmed[part.clone()];
490+ let lead = item.len() - item.trim_start().len();
491+ written.push_str(&trimmed[end..part.start + lead]);
492+ end = part.start + lead + item.trim().len();
493+ if item.trim().is_empty() {
496+ let at = column.map(|c| c + part.start + lead);
497+ let (value, text, filled) = self.item_value(item.trim(), line, at);
499+ written.push_str(&text);
502+ written.push_str(&trimmed[end..]);
503+ let list = value::List {
504+ items: Rc::new(items),
505+ written: Some(written.into()),
507+ return (Value::List(list), ok);
509+ let (text, ok) = self.fill(trimmed, line, column, Sink::Text);
510+ match value::written_range(&text) {
511+ Some(Ok(range)) => (range, ok),
512+ Some(Err(message)) => {
514+ interp::Problem::Invalid { message, offset: 0 },
518+ (Value::list(Vec::new()), false)
520+ None => (Value::Str(text), ok),
524+ /// An item of a list written in the source (see
525+ /// [`slot_value`](Self::slot_value)), and how it is written in the
531+ column: Option<usize>,
532+ ) -> (Value, String, bool) {
533+ let (value, ok) = match self.whole_value(item, line, column) {
534+ Some(value) => value,
535+ None if syntax::quoted_string(item).is_some() => {
536+ let (text, quoted, ok) = self.fill_value(item, line, column, Sink::Text);
537+ (quoted.map_or(Value::Str(text), Value::Quoted), ok)
540+ let (text, ok) = self.fill(item, line, column, Sink::Text);
541+ (Value::Str(text), ok)
544+ // Quoted text keeps its quotes in the list's text, as written
547+ .map_or_else(|| value.to_string(), str::to_string);
551+ /// The value of a slot that is exactly one `$name` or `${...}`, with its
552+ /// type; `None` when it is anything else.
557+ column: Option<usize>,
558+ ) -> Option<(Value, bool)> {
559+ let after = raw.strip_prefix('$')?;
560+ let (reference, len) = interp::reference(after, &self.env)?;
561+ if len != after.len() {
564+ track_var_refs(raw, &mut self.used_variables);
565+ let problem = match reference {
566+ interp::Reference::Var(path) => match interp::resolve(&path, &self.env) {
567+ Some(value) => return Some((value, true)),
568+ None => interp::Problem::Undefined {
573+ interp::Reference::Expr(source) => match crate::expr::eval(source, &self.env) {
574+ Ok(value) => return Some((value, true)),
575+ Err(crate::expr::Error::Invalid(message)) => {
576+ interp::Problem::Invalid { message, offset: 0 }
578+ Err(error) => error.at(2),
581+ self.report(problem, line, column);
582+ Some((Value::Str(raw.to_string()), false))
585+ /// Report a variable that can't be filled in, or an invalid `${...}`,
586+ /// at `offset` from `column`.
587+ fn report(&mut self, problem: interp::Problem, line: usize, column: Option<usize>) {
588+ let (line_text, column) = match &self.current_source {
589+ // The column is only shown with the line it points into
590+ (current, Some(text)) if *current == line => (Some(text.clone()), column),
593+ let diagnostic = match problem {
594+ interp::Problem::Undefined { name, offset } => {
595+ let column = column.map(|c| c + offset);
596+ let mut diagnostic = self.undefined(&name, line);
597+ if let Some(column) = column {
598+ diagnostic = diagnostic.column(column);
602+ interp::Problem::Invalid { message, offset } => {
603+ let diagnostic = Diagnostic::error(
604+ code::INVALID_EXPRESSION,
606+ format!("invalid expression: {}", message),
609+ Some(column) => diagnostic.column(column + offset),
613+ interp::Problem::CustomProperty { name, offset } => {
614+ let diagnostic = Diagnostic::error(
615+ code::INVALID_VALUE,
617+ interp::custom_property_message(&name),
619+ .subject(format!("${}", name))
620+ .suggest(Some(format!("var({})", name)));
622+ Some(column) => diagnostic.column(column + offset),
626+ interp::Problem::Record { message, offset } => {
627+ let diagnostic = Diagnostic::error(code::INVALID_VALUE, line, message);
629+ Some(column) => diagnostic.column(column + offset),
634+ let diagnostic = match line_text {
635+ Some(text) => diagnostic.source(text),
638+ self.push_once(diagnostic);
641+ /// Report a diagnostic unless the node being evaluated already did,
642+ /// so a line evaluated many times (in a loop, in a function) reports
643+ /// each problem once.
644+ fn push_once(&mut self, diagnostic: Diagnostic) {
649+ diagnostic.message.clone(),
651+ if self.reported.insert(key) {
652+ self.diagnostics.push(diagnostic);
656+ /// The error for `$name` with no definition: what the name is if it is
657+ /// something else, or the closest defined name.
658+ fn undefined(&mut self, name: &str, line: usize) -> Diagnostic {
659+ if self.env.bundle(name).is_some() {
660+ // Reported here, so not also as unused
661+ self.used_defines.insert(name.to_string());
662+ return Diagnostic::error(
663+ code::UNDEFINED_VARIABLE,
666+ "'${}' is an attribute bundle, not a value: it goes in an attribute list \
667+ as a whole attribute, `[${}]`",
673+ if self.env.function(name).is_some() {
674+ self.used_functions.insert(name.to_string());
675+ return Diagnostic::error(
676+ code::UNDEFINED_VARIABLE,
679+ "'${}' is a function, not a value: it is called as an element, `@{}`",
685+ // `$i-label` where `$i` is defined: a `-` joins a name
686+ if let Some((defined, rest)) = name
688+ .map(|(i, _)| (&name[..i], &name[i..]))
689+ .find(|(before, _)| self.env.value(before).is_some())
691+ return Diagnostic::error(
692+ code::UNDEFINED_VARIABLE,
695+ "undefined variable '${}': a `-` is part of a name. For '${}' followed \
696+ by '{}', write `${{{}}}{}`",
697+ name, defined, rest, defined, rest
702+ let suggestion = suggest_var_name(name, &self.env.value_names());
703+ let message = match (&suggestion, self.let_lines.get(name)) {
704+ (Some(closest), _) => format!(
705+ "undefined variable '${}', did you mean '${}'?",
708+ // Defined, but not where this line can see it
709+ (None, Some(_)) => format!(
710+ "undefined variable '${}': a `@let` defines it, but not where this line \
711+ can see it. A definition is visible from its line to the end of its \
712+ block, and a function's body sees what is defined above the function",
715+ (None, None) => format!("undefined variable '${}'", name),
717+ Diagnostic::error(code::UNDEFINED_VARIABLE, line, message)
719+ .suggest(suggestion)
722+ /// Note the node being evaluated, for diagnostics.
723+ fn enter(&mut self, node: &syntax::Node) {
724+ self.current_line = node.span.line;
725+ self.current_node = node.id;
727+ (node.line_count <= 1).then(|| format!("{}{}", " ".repeat(node.indent), node.source));
728+ self.current_source = (node.span.line, text);
731+ /// Parse a file's text into a tree whose ids don't clash with the
732+ /// trees parsed before it.
733+ fn parse_tree(&mut self, text: &str) -> Rc<Tree> {
734+ let tree = syntax::parse_from(text, self.next_id);
735+ self.next_id = tree.end_id;
739+ /// Read a file (once), relative to the current file.
740+ fn read_file(&mut self, resolved: &Path) -> std::io::Result<String> {
741+ if let Some(cached) = self.file_cache.get(resolved) {
742+ return Ok(cached.clone());
744+ let text = std::fs::read_to_string(resolved)?;
745+ self.file_cache.insert(resolved.to_path_buf(), text.clone());
749+ fn resolve(&self, filename: &str) -> PathBuf {
750+ match &self.base_path {
751+ Some(base) => base.join(filename),
752+ None => PathBuf::from(filename),
@@ -127,11 +759,19 @@ impl ParseContext {
127const PRELUDE: &str = include_str!("std.hl");
759const PRELUDE: &str = include_str!("std.hl");
129fn load_prelude(ctx: &mut ParseContext) {
761fn load_prelude(ctx: &mut ParseContext) {
130− let _ = Evaluator.eval_block(&syntax::parse(PRELUDE), ctx);
762+ // The library's definitions are in a block of their own, around the
763+ // file's, so the file's own `@let` of the same name hides them
765+ let tree = ctx.parse_tree(PRELUDE);
766+ collect_namespace(&tree.nodes, None, &mut HashSet::new(), ctx);
767+ ctx.current_file = Some("std.hl".to_string());
768+ let _ = Evaluator.eval_block(&tree.nodes, ctx);
769+ ctx.current_file = None;
131 // Library definitions aren't the file's own: never report them unused.
770 // Library definitions aren't the file's own: never report them unused.
132 ctx.fn_lines.clear();
771 ctx.fn_lines.clear();
133 ctx.define_lines.clear();
772 ctx.define_lines.clear();
134 ctx.let_lines.clear();
773 ctx.let_lines.clear();
137pub fn parse(input: &str) -> ParseResult {
777pub fn parse(input: &str) -> ParseResult {
@@ -139,20 +779,18 @@ pub fn parse(input: &str) -> ParseResult {
141pub fn parse_with_base(input: &str, base_path: Option<&Path>) -> ParseResult {
781pub fn parse_with_base(input: &str, base_path: Option<&Path>) -> ParseResult {
142− let tree = syntax::parse(input);
143 let mut ctx = ParseContext {
782 let mut ctx = ParseContext {
144 current_line: 0,
783 current_line: 0,
145− scoped_functions: std::collections::HashSet::new(),
784+ page: None,
146− page_title: None,
785+ page_at: None,
149 meta_tags: Vec::new(),
786 meta_tags: Vec::new(),
150 head_blocks: Vec::new(),
787 head_blocks: Vec::new(),
151− variables: HashMap::new(),
788+ head_at: None,
152− defines: HashMap::new(),
789+ env: Env::default(),
153− functions: HashMap::new(),
790+ defined_functions: HashMap::new(),
154 css_vars: Vec::new(),
791 css_vars: Vec::new(),
155 custom_css: Vec::new(),
792 custom_css: Vec::new(),
793+ scoped_css: Vec::new(),
156 og_tags: Vec::new(),
794 og_tags: Vec::new(),
157 diagnostics: Vec::new(),
795 diagnostics: Vec::new(),
158 base_path: base_path.map(|p| p.to_path_buf()),
796 base_path: base_path.map(|p| p.to_path_buf()),
@@ -166,22 +804,84 @@ pub fn parse_with_base(input: &str, base_path: Option<&Path>) -> ParseResult {
166 let_lines: HashMap::new(),
804 let_lines: HashMap::new(),
167 fn_lines: HashMap::new(),
805 fn_lines: HashMap::new(),
168 define_lines: HashMap::new(),
806 define_lines: HashMap::new(),
807+ visited: HashSet::new(),
810+ included_by: Rc::default(),
811+ namespace: HashSet::new(),
812+ current_source: (0, None),
813+ reported: HashSet::new(),
170 load_prelude(&mut ctx);
820 load_prelude(&mut ctx);
171− let nodes = Evaluator.eval_block(&tree, &mut ctx);
821+ let tree = ctx.parse_tree(input);
172− validate_tree(&nodes, None, &mut ctx.diagnostics);
822+ ctx.diagnostics.extend(tree.diagnostics.iter().cloned());
173− check_unused(&mut ctx);
823+ ctx.trees.push((tree.clone(), None));
826+ base_path.map(Path::to_path_buf),
827+ &mut HashSet::new(),
830+ let nodes = Evaluator.eval_block(&tree.nodes, &mut ctx);
831+ check_unevaluated(&mut ctx);
832+ check_slot_places(&mut ctx);
833+ validate_tree(&nodes, None, false, &mut ctx.diagnostics);
834+ // A library's definitions are for the files that include it
835+ let library = is_library_file(&tree, base_path, &mut ctx, &mut Vec::new());
836+ let exported: HashSet<String> = if library {
839+ .filter_map(|node| match node.directive().map(|d| &d.args) {
840+ Some(DirectiveArgs::Let(def)) => Some(def.name.clone()),
847+ check_unused(&mut ctx, &exported);
848+ if let (None, Some(line)) = (&ctx.page, ctx.head_at)
851+ ctx.diagnostics.push(Diagnostic::warning(
854+ "a file without @page is a fragment, which has no <head>: @meta and @head are \
855+ left out of it (give the file a @page, or put them in the page that includes it)"
859+ dedupe(&mut ctx.diagnostics);
860+ // What the file itself defines at its top level
861+ let file = ctx.env.frames.last().cloned().unwrap_or_default();
862+ let mut variables = HashMap::new();
863+ let mut defines = HashMap::new();
864+ for (name, binding) in file.iter() {
866+ Binding::Value(value) => {
867+ variables.insert(name.clone(), value.to_string());
869+ Binding::Bundle(attrs) => {
870+ defines.insert(name.clone(), attrs.to_vec());
872+ Binding::Function(_) => {}
174 ParseResult {
875 ParseResult {
175 document: Document {
876 document: Document {
176− page_title: ctx.page_title,
877+ page: ctx.page,
178− favicon: ctx.favicon,
179 meta_tags: ctx.meta_tags,
878 meta_tags: ctx.meta_tags,
180 head_blocks: ctx.head_blocks,
879 head_blocks: ctx.head_blocks,
181− variables: ctx.variables,
880+ variables,
182− defines: ctx.defines,
881+ defines,
183 css_vars: ctx.css_vars,
882 css_vars: ctx.css_vars,
184 custom_css: ctx.custom_css,
883 custom_css: ctx.custom_css,
884+ scoped_css: ctx.scoped_css,
185 og_tags: ctx.og_tags,
885 og_tags: ctx.og_tags,
@@ -191,458 +891,873 @@ pub fn parse_with_base(input: &str, base_path: Option<&Path>) -> ParseResult {
193// ---------------------------------------------------------------------------
893// ---------------------------------------------------------------------------
194−// Preprocessing: strip comments/blanks, collapse @raw blocks
894+// Code that never runs: an untaken branch, an uncalled function, a loop over
195−// ---------------------------------------------------------------------------
895+// an empty list
197−// ---------------------------------------------------------------------------
199// ---------------------------------------------------------------------------
896// ---------------------------------------------------------------------------
201−impl Evaluator {
898+/// Collect the functions defined anywhere in `nodes` and in the files they
202− fn eval_block(&mut self, block: &[Syntax], ctx: &mut ParseContext) -> Vec<Node> {
899+/// include (by a literal path), into `ctx.namespace`.
203− let mut nodes = Vec::new();
900+fn collect_namespace(
204− for node in block {
901+ nodes: &[syntax::Node],
205− match self.eval(node, ctx) {
902+ base: Option<PathBuf>,
206− Ok(Some(new_nodes)) => nodes.extend(new_nodes),
903+ seen: &mut HashSet<PathBuf>,
207− Ok(None) => {}
904+ ctx: &mut ParseContext,
208− // Record the error and go on, to report several in one pass
905+) {
209− Err(e) => ctx.diagnostics.push(Diagnostic {
906+ let mut includes = Vec::new();
210− line: e.line,
907+ for node in nodes {
211− column: None,
908+ node.walk(&mut |node| match node.directive().map(|d| &d.args) {
212− message: e.message,
909+ Some(DirectiveArgs::Let(def)) if matches!(def.form, LetForm::Function(_)) => {
213− severity: Severity::Error,
910+ ctx.namespace.insert(def.name.clone());
214− source_line: Some(node.source()),
912+ Some(DirectiveArgs::Text(Some(path))) if node.is_directive("include") => {
913+ includes.push(path.raw.clone());
918+ for path in includes {
919+ let path = path.trim_matches('"');
920+ if path.contains('$') {
218− nodes
923+ let resolved = match &base {
924+ Some(base) => base.join(path),
925+ None => PathBuf::from(path),
927+ if !seen.insert(resolved.clone()) {
930+ let Ok(text) = ctx.read_file(&resolved) else {
933+ let tree = syntax::parse(&text);
934+ let parent = resolved.parent().map(Path::to_path_buf);
935+ collect_namespace(&tree.nodes, parent, seen, ctx);
221− /// Evaluate a block in its own scope: `@let` inside doesn't leak out.
939+/// Check the lines that were never evaluated: element and function names,
222− fn eval_scoped(&mut self, block: &[Syntax], ctx: &mut ParseContext) -> Vec<Node> {
940+/// and the attributes of built-in elements (those that don't depend on a
223− let saved_vars = ctx.variables.clone();
941+/// variable). Names that come from data are only checked when evaluated.
224− let nodes = self.eval_block(block, ctx);
942+fn check_unevaluated(ctx: &mut ParseContext) {
225− ctx.variables = saved_vars;
943+ let trees = std::mem::take(&mut ctx.trees);
226− nodes
944+ let mut seen = HashSet::new();
945+ for (tree, chain) in &trees {
946+ let before = ctx.diagnostics.len();
947+ for node in &tree.nodes {
948+ check_unevaluated_node(node, ctx);
950+ let mut found = ctx.diagnostics.split_off(before);
951+ if let Some(chain) = chain {
952+ for d in &mut found {
953+ d.message = format!("{}\n in {}", d.message, chain);
956+ // A file included twice is checked twice: report each problem once
957+ found.retain(|d| seen.insert((d.line, d.message.clone())));
958+ ctx.diagnostics.extend(found);
229− fn eval(
963+fn check_unevaluated_node(node: &syntax::Node, ctx: &mut ParseContext) {
230− &mut self,
964+ if !ctx.visited.contains(&node.id) {
231− node: &Syntax,
965+ let line = node.span.line;
232− ctx: &mut ParseContext,
966+ // A reference from code that doesn't run still counts as a use
233− ) -> Result<Option<Vec<Node>>, ParseError> {
967+ track_var_refs(&node.source, &mut ctx.used_variables);
234− let line_num = node.line();
968+ let before = ctx.diagnostics.len();
235− ctx.current_line = line_num;
969+ match &node.kind {
236− let (content, current_indent, children) = match node {
970+ NodeKind::Element(element) => {
237− Syntax::Raw { text, .. } => return Ok(Some(vec![Node::Raw(text.clone())])),
971+ for head in &element.chain {
238− Syntax::Function {
972+ check_head(head, line, ctx);
240− params,
974+ check_unevaluated_content(node, element, ctx);
241− defaults,
975+ if let Some(text) = &element.text {
242− body,
976+ check_inline_heads(text, line, ctx);
245− self.define_function(name, params, defaults, body, line_num, ctx);
248− Syntax::If { branches } => {
249− // Every condition is checked (and its errors reported);
250− // the first that holds picks the branch.
251− let mut chosen = None;
252− for branch in branches {
253− let holds = match &branch.condition {
254− Some(condition) => ctx.condition(condition, branch.line),
257− if holds && chosen.is_none() {
258− chosen = Some(&branch.body);
261− return Ok(chosen.map(|body| self.eval_scoped(body, ctx)));
263− Syntax::Each {
979+ NodeKind::Text(text) => check_inline_heads(text, line, ctx),
264− header,
980+ // `@page`'s attributes are checked like an element's (a layout's
265− body,
981+ // `@page` is in a function that may not run in this file)
266− empty,
982+ NodeKind::Directive(syntax::Directive {
984+ DirectiveArgs::Page {
985+ attrs: Some(list), ..
269− return self.eval_each(header, body, empty, line_num, ctx).map(Some);
989+ let words: Vec<String> = crate::vocab::PAGE_WORDS
991+ .map(|w| w.to_string())
994+ check_attrs(&list.attrs, line, ctx, &words);
995+ ctx.in_page = false;
996+ check_page_tokens(&list.attrs, line, ctx);
271− Syntax::Line {
998+ _ => {}
276− } => (text.clone(), *indent, children),
279− // --- Directives ---
281− // @page [lang en, favicon /f.png] Title
282− if let Some(rest) = content.strip_prefix("@page ") {
283− let rest = rest.trim_start();
284− let title = if rest.starts_with('[') {
285− let (attrs, title) = parse_attr_brackets_no_validate(rest, line_num, ctx)?;
287− let value = attr.value.unwrap_or_default();
288− match attr.key.as_str() {
289− "lang" => ctx.lang = Some(value),
290− "favicon" => ctx.favicon = Some(value),
291− other => ctx.diagnostics.push(Diagnostic {
295− "unknown @page attribute '{}' (expected lang or favicon)",
298− severity: Severity::Warning,
299− source_line: Some(content.clone()),
307− ctx.page_title = Some(substitute_vars(title.trim(), &ctx.variables));
1000+ let text = written_line(node);
1001+ for d in &mut ctx.diagnostics[before..] {
1002+ d.source_line.get_or_insert_with(|| text.as_str().into());
1005+ for child in &node.children {
1006+ check_unevaluated_node(child, ctx);
311− if let Some(rest) = content.strip_prefix("@let ") {
1010+/// Check the content passed to the calls of a line that was never
312− let rest = rest.trim();
1011+/// evaluated: its `@slot NAME` blocks, and, for a function without
313−
1012+/// `@children`, any other content.
314− if !children.is_empty() {
1013+fn check_unevaluated_content(
315− return Err(ParseError {
1014+ node: &syntax::Node,
316− line: line_num,
1015+ element: &syntax::ElementLine,
317− message: "@let with body requires a name".to_string(),
1016+ ctx: &mut ParseContext,
319− }
1018+ let calls: Vec<Option<(String, Rc<FnDef>)>> = element
321− if let Some((name, value)) = rest.split_once(' ') {
1020+ .iter()
322− let value = value.trim();
1021+ .map(|head| {
323− // `@let name = EXPR` computes its value (see expr.rs); any
1022+ let function = ctx.defined_functions.get(&head.name)?;
324− // other value is literal text with `$var` interpolation.
1023+ Some((head.name.clone(), function.clone()))
325− if let Some(expression) = value.strip_prefix('=') {
1024+ })
326− let value = ctx
1025+ .collect();
327− .eval(expression.trim(), line_num)
1026+ check_fillers(node, element, &calls, ctx);
328− .map(|v| v.to_string())
1027+ let last = calls.len() - 1;
329− .unwrap_or_default();
1028+ for (i, call) in calls.iter().enumerate() {
330− if name.starts_with("--") {
1029+ let Some((name, function)) = call else {
331− ctx.css_vars.push((name.to_string(), value.clone()));
1030+ continue;
333− ctx.variables.insert(name.to_string(), value);
1032+ if function.has_children || function.wraps_itself {
334− ctx.let_lines.entry(name.to_string()).or_insert(line_num);
1033+ continue;
335− return Ok(None);
1034+ }
336− }
1035+ let content = if i == last {
337−
1036+ element.text.is_some() || holds_content(&node.children, ctx)
338− // Attribute bundle: @let name [attr1, attr2, ...]
1037+ } else {
339− if value.starts_with('[') {
1038+ element.chain[i + 1].name != "slot" || !slot_is_built_in(ctx)
340− let (attrs, _) = parse_attr_brackets(value, line_num, ctx)?;
1039+ };
341− ctx.defines.insert(name.to_string(), attrs);
1040+ if content {
342− ctx.define_lines.entry(name.to_string()).or_insert(line_num);
1041+ let head = &element.chain[i];
343− return Ok(None);
1042+ ctx.push_once(no_children(
1045+ name_column(head, node.span.line),
346− let value = if value.starts_with('"') && value.ends_with('"') && value.len() >= 2 {
1051+/// Check a head that was never evaluated: its name, and its attributes
347− // Support quoted string interpolation: @let greeting "Hello $name"
1052+/// (for a call, see [`check_call`]).
348− &value[1..value.len() - 1]
1053+fn check_head(head: &syntax::Head, line: usize, ctx: &mut ParseContext) {
349− } else {
1054+ let is_function =
350− value
1055+ ctx.namespace.contains(&head.name) || ctx.defined_functions.contains_key(&head.name);
351− };
1056+ if is_function {
352− track_var_refs(value, &mut ctx.used_variables);
1057+ ctx.used_functions.insert(head.name.clone());
353− let value = substitute_vars(value, &ctx.variables);
1058+ if let Some(function) = ctx.defined_functions.get(&head.name).cloned()
354− if name.starts_with("--") {
1059+ && !function.wraps_itself
355− // CSS custom property
1060+ {
356− ctx.css_vars.push((name.to_string(), value.clone()));
1061+ check_call(head, &function, line, ctx);
1065+ let kind = match parse_element_kind(&head.name, line, ctx) {
1068+ ctx.diagnostics.push(e);
1072+ if let Some(list) = &head.attrs {
1073+ check_attrs(&list.attrs, line, ctx, &[]);
1074+ // A word for laying out children on an element that doesn't lay
1075+ // them out, as where the code runs (see `validate_tree`)
1076+ if !kind.layout().is_container() && !has_no_element(&kind) {
1077+ for attr in &list.attrs {
1078+ let base = crate::vocab::base_attribute(&attr.key);
1080+ && attr.choice.is_none()
1081+ && attr.prefixed.is_none()
1082+ && crate::vocab::CONTAINER_ATTRIBUTES.contains(&base)
1083+ && !crate::vocab::split_prefixes(&attr.key)
1085+ .contains(&"children:")
1087+ ctx.push_once(not_a_container(&kind, line, base).column(attr.span.column));
358− ctx.variables.insert(name.to_string(), value);
359− ctx.let_lines.entry(name.to_string()).or_insert(line_num);
364− // @meta NAME VALUE; `og:` names become Open Graph property tags
1094+/// The attributes of a list that is never evaluated that can be checked
365− if let Some(rest) = content.strip_prefix("@meta ") {
1095+/// together: not bundles or `if()`s. Names are checked; a value with a
366− let rest = rest.trim();
1096+/// variable in it depends on what the variable holds, so only a literal
367− if let Some((name, value)) = rest.split_once(' ') {
1097+/// value is (the other is checked as an empty value).
368− let value = substitute_vars(value.trim(), &ctx.variables);
1098+/// `@page`'s own rules (see `check_page_attr`) for a list that isn't
369− match name.trim().strip_prefix("og:") {
1099+/// evaluated, as written: a value made from a variable counts as given.
370− Some(property) => ctx.og_tags.push((property.to_string(), value)),
1100+fn check_page_tokens(tokens: &[syntax::Attr], line: usize, ctx: &mut ParseContext) {
371− None => ctx.meta_tags.push((name.trim().to_string(), value)),
1101+ for token in tokens {
1102+ match &token.choice {
1104+ for branch in &choice.branches {
1105+ check_page_tokens(branch.attrs(), line, ctx);
374− return Ok(None);
1108+ // Under prefixes there are only styles
1109+ None if token.key.starts_with('$') || token.prefixed.is_some() => {}
1111+ let value = token.value.as_deref().map(|v| v.trim_matches('"'));
1112+ let value = match value {
1113+ Some(v) if v.contains('$') => Some("$"),
1121+ Some(token.span.column),
377− if content == "@head" || content.starts_with("@head ") {
1129+fn literal_attrs(tokens: &[syntax::Attr]) -> Vec<syntax::Attr> {
378− let trimmed = block_text(children).trim().to_string();
1130+ // A prefixed group is checked with its prefixes, as far as its own
379− if !trimmed.is_empty() {
1131+ // attributes can be; a prefixed bundle or `if()` depends on what it holds
380− ctx.head_blocks.push(trimmed);
1132+ let group = |a: &syntax::Attr| {
1133+ let prefixed = a.prefixed.as_ref()?;
1134+ let syntax::Branch::Group { list, trailing } = &prefixed.target else {
1137+ let mut list = list.clone();
1138+ list.attrs = literal_attrs(&list.attrs);
1139+ let mut a = a.clone();
1140+ a.prefixed = Some(Box::new(syntax::Prefixed {
1141+ target: syntax::Branch::Group {
1143+ trailing: trailing.clone(),
1145+ ..(**prefixed).clone()
1149+ let groups = tokens.iter().filter_map(group);
1153+ let bundle = a.key.starts_with('$') && a.value.is_none() && !a.html;
1154+ a.choice.is_none() && a.prefixed.is_none() && !bundle
1157+ let mut a = a.clone();
1158+ let variable = |v: &String| v.contains('$');
1159+ if !a.key.contains('$') && a.value.as_ref().is_some_and(variable) {
1160+ a.value = Some(String::new());
1161+ a.raw = format!("{} ", a.key);
382− return Ok(None);
1163+ a
1169+/// Check a call that was never evaluated: how it passes its parameters
1170+/// (none written `name=value`, and every one without a default passed,
1171+/// when no bundle or `if()` could pass it), and its other attributes, like
1172+/// those of an element.
1173+fn check_call(head: &syntax::Head, function: &FnDef, line: usize, ctx: &mut ParseContext) {
1174+ let name = head.name.as_str();
1175+ let attrs = head.attrs.as_ref().map_or(&[][..], |list| &list.attrs[..]);
1176+ written_parameter_forms(name, function, attrs, line, ctx);
1177+ if let Some(list) = &head.attrs {
1178+ let params: Vec<String> = function.params.iter().map(|p| p.name.clone()).collect();
1179+ check_attrs(&list.attrs, line, ctx, ¶ms);
1181+ let unknown = attrs
1183+ .any(|a| a.choice.is_some() || (a.key.starts_with('$') && a.value.is_none()));
1187+ for param in function.params.iter().filter(|p| p.default.is_none()) {
1188+ if !attrs.iter().any(|a| a.key == param.name) {
1189+ let column = name_column(head, line);
1190+ ctx.push_once(missing_parameter(name, ¶m.name, line, column));
385− // --- @style block (raw CSS) ---
1195+/// Report each parameter a call's list writes `name=value`, with the value
386− if content.trim() == "@style" {
1196+/// as written and its column; returns their names, so the evaluated call
387− let trimmed = block_text(children).trim().to_string();
1197+/// doesn't report them again.
388− if !trimmed.is_empty() {
1198+fn written_parameter_forms(
389− ctx.custom_css.push(trimmed);
1199+ name: &str,
390− }
1200+ function: &FnDef,
391− return Ok(None);
1201+ attrs: &[syntax::Attr],
1203+ ctx: &mut ParseContext,
1205+ let mut reported = Vec::new();
1206+ for attr in attrs {
1207+ if !(attr.html && function.is_param(&attr.key)) {
1210+ let at = if attr.span.line == 0 {
1215+ let value = attr.value.as_deref().unwrap_or("");
1216+ let diagnostic = parameter_form(name, &attr.key, value, at).column(attr.span.column);
1217+ ctx.push_once(match &ctx.current_source {
1218+ (current, Some(text)) if *current == at => diagnostic.source(text.clone()),
1221+ reported.push(attr.key.clone());
394− // --- @markdown block or file (convert markdown to HTML) ---
1226+fn check_inline_heads(text: &syntax::Text, line: usize, ctx: &mut ParseContext) {
395− if content.trim() == "@markdown" || content.trim().starts_with("@markdown ") {
1227+ for segment in &text.segments {
396− let arg = content.trim().strip_prefix("@markdown").unwrap().trim();
1228+ if let Segment::Inline(inline) = segment {
397− if arg.is_empty() {
1229+ check_head(&inline.head, line, ctx);
398− // Inline markdown block: indented children
1230+ if let Some(text) = &inline.text {
399− let md_lines: Vec<String> =
1231+ check_inline_heads(text, line, ctx);
400− block_text(children).lines().map(String::from).collect();
401− let html = markdown_to_html(&md_lines);
402− return Ok(Some(vec![Node::Raw(html)]));
404− // External markdown file: @markdown file.md
405− let filename = substitute_vars(arg, &ctx.variables);
406− let resolved = match &ctx.base_path {
407− Some(base) => base.join(&filename),
408− None => PathBuf::from(&filename),
410− let md_text = if let Some(cached) = ctx.file_cache.get(&resolved) {
413− match std::fs::read_to_string(&resolved) {
415− ctx.file_cache.insert(resolved.clone(), text.clone());
419− ctx.diagnostics.push(Diagnostic {
422− message: format!("cannot read markdown '{}': {}", filename, e),
423− severity: Severity::Error,
424− source_line: Some(content.clone()),
430− ctx.included_files.push(resolved);
431− let md_lines: Vec<String> = md_text.lines().map(|l| l.to_string()).collect();
432− let html = markdown_to_html(&md_lines);
433− return Ok(Some(vec![Node::Raw(html)]));
437− if let Some(rest) = content.strip_prefix("@include ") {
1237+// ---------------------------------------------------------------------------
438− let rest = rest.trim();
1238+// Evaluation
439− let filename = rest
1239+// ---------------------------------------------------------------------------
441− .and_then(|f| f.strip_suffix('"'))
443− let filename = substitute_vars(filename, &ctx.variables);
445− let resolved = match &ctx.base_path {
1241+/// The `@else` lines that continue the `@if` or `@each` before `from`, and
446− Some(base) => base.join(&filename),
1242+/// the position after them.
447− None => PathBuf::from(&filename),
1243+fn else_branches(block: &[syntax::Node], from: usize, is_if: bool) -> (Vec<&syntax::Node>, usize) {
448− };
1244+ let mut branches = Vec::new();
1245+ let mut next = from;
1247+ while i < block.len() {
1248+ let node = &block[i];
1250+ if node.is_trivia() {
1253+ let condition = match node.directive().map(|d| &d.args) {
1254+ Some(DirectiveArgs::Else { condition }) => condition.is_some(),
1257+ if condition && !is_if {
1260+ branches.push(node);
450− if ctx.include_stack.contains(&resolved) {
1269+impl Evaluator {
451− let cycle_chain = format_include_chain(&ctx.include_stack);
1270+ fn eval_block(&mut self, block: &[syntax::Node], ctx: &mut ParseContext) -> Vec<Node> {
452− ctx.diagnostics.push(Diagnostic {
1271+ let mut nodes = Vec::new();
453− line: line_num,
1272+ let mut i = 0;
454− column: None,
1273+ while i < block.len() {
455− message: format!(
1274+ let node = &block[i];
456− "circular include '{}' (cycle: {} → {})",
1275+ i += 1;
457− filename, cycle_chain, filename
1276+ if node.is_trivia() {
459− severity: Severity::Error,
460− source_line: Some(content.clone()),
464−
1279+ let result = match node.directive().map(|d| d.name()) {
465− let imported_text = if let Some(cached) = ctx.file_cache.get(&resolved) {
1280+ Some(name @ ("if" | "each")) => {
466− cached.clone()
1281+ let (branches, next) = else_branches(block, i, name == "if");
467− } else {
1282+ i = next;
468− match std::fs::read_to_string(&resolved) {
1283+ if name == "if" {
469− Ok(text) => {
1284+ Ok(Some(self.eval_if(node, &branches, ctx)))
470− ctx.file_cache.insert(resolved.clone(), text.clone());
1285+ } else {
471− text
1286+ self.eval_each(node, branches.first().copied(), ctx)
474− ctx.diagnostics.push(Diagnostic {
477− message: format!("cannot include '{}': {}", filename, e),
478− severity: Severity::Error,
479− source_line: Some(content.clone()),
1289+ // Reported as a syntax error
1291+ ctx.visited.insert(node.id);
1294+ _ => self.eval(node, ctx),
486− ctx.included_files.push(resolved.clone());
1297+ Ok(Some(new_nodes)) => nodes.extend(new_nodes),
487− ctx.include_stack.push(resolved.clone());
1298+ Ok(None) => {}
488− let saved_base = ctx.base_path.clone();
1299+ // Record the error and go on, to report several in one pass
489− ctx.base_path = resolved.parent().map(|p| p.to_path_buf());
1300+ Err(mut e) => {
491− let diag_count_before = ctx.diagnostics.len();
1302+ .get_or_insert_with(|| node.source.as_str().into());
492−
1303+ ctx.diagnostics.push(e);
493− let included_nodes = self.eval_block(&syntax::parse(&imported_text), ctx);
1304+ }
495− // Annotate new diagnostics with import chain
496− let import_chain = format_include_chain(&ctx.include_stack);
497− for d in &mut ctx.diagnostics[diag_count_before..] {
498− d.message = format!("{}\n in {}", d.message, import_chain);
501− ctx.base_path = saved_base;
502− ctx.include_stack.pop();
503− return Ok(Some(included_nodes));
506− // --- @data (load JSON file into variables) ---
1310+ /// Evaluate a block in its own scope: what it defines is visible to
1311+ /// the end of the block, and not after it.
1312+ fn eval_scoped(&mut self, block: &[syntax::Node], ctx: &mut ParseContext) -> Vec<Node> {
1314+ let nodes = self.eval_block(block, ctx);
508− // @data $name file.json values as $name.key
1319+ /// `@if` with its `@else if` / `@else` branches. Every condition is
509− // @data $name dir/*.json a list of the files' records
1320+ /// checked (and its errors reported); the first that holds picks the
510− // @data $name [...] / {...} inline JSON
1321+ /// branch.
511− // @data $name env:NAME [DEFAULT] an environment variable
1322+ fn eval_if(
512− if let Some(rest) = content.strip_prefix("@data ") {
1323+ &mut self,
513− let rest = rest.trim();
1324+ node: &syntax::Node,
514− let Some((prefix, filename)) = rest
1325+ branches: &[&syntax::Node],
515− .strip_prefix('$')
1326+ ctx: &mut ParseContext,
516− .and_then(|named| named.split_once(char::is_whitespace))
1327+ ) -> Vec<Node> {
517− .map(|(name, source)| (name.to_string(), source.trim().to_string()))
1328+ let mut chosen = None;
518− else {
1329+ for branch in std::iter::once(node).chain(branches.iter().copied()) {
519− return Err(ParseError {
1330+ ctx.visited.insert(branch.id);
520− line: line_num,
1331+ ctx.enter(branch);
521− message: format!(
1332+ let holds = match branch.directive().map(|d| &d.args) {
522− "@data needs a name: write `@data $name {}` and use `$name.key`",
1333+ Some(DirectiveArgs::Condition(condition))
523− rest.trim_start_matches('$')
1334+ | Some(DirectiveArgs::Else {
524− ),
1335+ condition: Some(condition),
1337+ !condition.raw.is_empty()
1341+ Some(condition.span.column),
1344+ Some(DirectiveArgs::Else { condition: None }) => true,
1345+ // A syntax error, already reported
1348+ if holds && chosen.is_none() {
1349+ chosen = Some(&branch.children);
1352+ chosen.map_or_else(Vec::new, |body| self.eval_scoped(body, ctx))
1357+ node: &syntax::Node,
1358+ ctx: &mut ParseContext,
1359+ ) -> Result<Option<Vec<Node>>, ParseError> {
1360+ ctx.visited.insert(node.id);
1363+ NodeKind::Blank | NodeKind::Comment => Ok(None),
1364+ // `@code` and `@textarea` show their body as text; `@script`'s
1365+ // goes into the page as it is
1366+ NodeKind::Verbatim(body) if body.escaped => {
1367+ let text = body.text.trim_matches('\n').to_string();
1368+ Ok(Some(vec![Node::Text(vec![TextSegment::Plain(text)])]))
1370+ NodeKind::Verbatim(body) => Ok(Some(vec![Node::Raw(body.text.clone())])),
1371+ NodeKind::Directive(directive) => {
1372+ let mut nodes = self.eval_directive(node, directive, ctx)?;
1373+ // A directive that takes no body: the lines indented under
1374+ // it (a syntax error) are evaluated as its siblings. A
1375+ // @let's body belongs to it even under a value (also an
1376+ // error), so it is never evaluated in place.
1377+ let takes_body = directive.spec.body != BodyKind::None;
1379+ let siblings = self.eval_block(&node.children, ctx);
1380+ nodes.get_or_insert_with(Vec::new).extend(siblings);
1384+ NodeKind::Element(element) => self.eval_element(node, element, ctx).map(Some),
1385+ NodeKind::Text(text) => {
1386+ let mut nodes = vec![Node::Text(text_segments(text, ctx))];
1387+ // Text takes no body: lines indented under it are its
1389+ nodes.extend(self.eval_block(&node.children, ctx));
528− if let Some(env) = filename.strip_prefix("env:") {
1395+ fn eval_directive(
529− let (var, default) = match env.split_once(char::is_whitespace) {
1396+ &mut self,
530− Some((var, default)) => (var, Some(default.trim())),
1397+ node: &syntax::Node,
531− None => (env, None),
1398+ directive: &syntax::Directive,
1399+ ctx: &mut ParseContext,
1400+ ) -> Result<Option<Vec<Node>>, ParseError> {
1401+ let line_num = node.span.line;
1402+ let content = &node.source;
1403+ match (directive.name(), &directive.args) {
1404+ // @page [lang=en, favicon /f.png, background #f8fafc] Title
1405+ ("page", DirectiveArgs::Page { attrs, title }) => {
1406+ let page = read_page(attrs.as_ref(), title.as_ref(), line_num, ctx);
1407+ // A page has one root: a second `@page` (a layout called
1408+ // twice, or one called after the page's own) is an error
1409+ let here = match &ctx.current_file {
1410+ Some(file) => format!("line {} of {}", line_num, file),
1411+ None => format!("line {}", line_num),
533− let value = std::env::var(var)
1413+ if let Some(first) = &ctx.page_at {
534− .ok()
1414+ let again = if *first == here {
535− .or_else(|| default.map(|d| substitute_vars(d, &ctx.variables)));
1415+ "this @page runs a second time (in a loop, or in a function called \
536− if value.is_none() {
1416+ twice)"
537− ctx.diagnostics.push(Diagnostic {
1417+ .to_string()
538− line: line_num,
1418+ } else {
539− column: None,
1419+ format!("a second @page (this page already has one, on {})", first)
540− message: format!(
1420+ };
541− "environment variable '{}' is not set and has no default",
1421+ let diagnostic = Diagnostic::error(
542− var
1422+ code::DUPLICATE_PAGE,
1425+ "{}: a page has one @page, the root element that styles its <body>",
544− severity: Severity::Warning,
1428+ )
545− source_line: Some(content.clone()),
1429+ .source(content.clone())
546− });
1430+ .subject("@page");
1431+ ctx.diagnostics.push(diagnostic);
1433+ ctx.page_at = Some(here);
1434+ ctx.page = Some(page);
548− ctx.variables.insert(prefix, value.unwrap_or_default());
1436+ Ok(None)
552− // Inline JSON: @data $links [{"label": "Home", "url": "/"}]
1439+ ("let", DirectiveArgs::Let(def)) => {
553− let (json_text, source) = if filename.starts_with(['[', '{']) {
1440+ let name = def.name.as_str();
554− (filename, "the inline data".to_string())
1441+ // Values, bundles and functions share one namespace: a
555− } else {
1442+ // definition replaces whatever the name meant in its block
556− let filename = substitute_vars(&filename, &ctx.variables);
1443+ match &def.form {
557− if filename.contains('*') {
1444+ LetForm::Function(function) => {
558− self.load_data_glob(&prefix, &filename, line_num, &content, ctx);
1445+ self.define_function(name, &function.params, node, ctx);
1447+ // `@let name = EXPR` computes its value (see expr.rs)
1448+ LetForm::Computed(expression) => {
1450+ .eval(&expression.raw, line_num, Some(expression.span.column))
1451+ .unwrap_or_else(Value::empty);
1452+ set_variable(name, value, line_num, ctx);
1454+ // Attribute bundle: @let name [attr1, attr2, ...]
1455+ LetForm::Bundle(list) => {
1456+ ctx.in_bundle = true;
1457+ let attrs = parse_attr_list(&list.attrs, line_num, ctx, true, &[]);
1458+ ctx.in_bundle = false;
1459+ ctx.env.define(name, Binding::Bundle(Rc::new(attrs)));
1460+ ctx.define_lines.entry(name.to_string()).or_insert(line_num);
1462+ // `@let size 16px`, `@let fruits apple, banana`,
1463+ // `@let post $posts.0`: see `slot_value`
1464+ LetForm::Value(value) => {
1466+ ctx.slot_value(&value.raw, value.span.line, Some(value.span.column));
1467+ set_variable(name, value, line_num, ctx);
1469+ // Quoted text: `@let arrow "→ "`
1470+ LetForm::Quoted(value) => {
1471+ let raw = format!("\"{}\"", value.raw);
1472+ let column = value.span.column.saturating_sub(1);
1473+ let (text, quoted, _) =
1474+ ctx.fill_value(&raw, value.span.line, Some(column), Sink::Text);
1475+ let value = quoted.map_or(Value::Str(text), Value::Quoted);
1476+ set_variable(name, value, line_num, ctx);
1482+ // @meta NAME VALUE; `og:` names become Open Graph property tags
1483+ ("meta", DirectiveArgs::Text(Some(arg))) => {
1484+ let Some((name, value)) = arg.raw.split_once(char::is_whitespace) else {
1485+ ctx.diagnostics.push(
1487+ code::MISSING_ARGUMENT,
1489+ format!("@meta needs a name and a value: `@meta {} VALUE`", arg.raw),
1491+ .source(content.clone()),
559 return Ok(None);
1493 return Ok(None);
1495+ let value_column = arg.span.column + arg.raw.len() - value.trim_start().len();
1496+ // An HTML attribute value: quoted text loses its quotes
1497+ let (value, _, _) =
1498+ ctx.fill_value(value.trim(), line_num, Some(value_column), Sink::Text);
1499+ // The same tag twice says nothing more (a layout called
1500+ // twice): it is written once
1501+ let (tags, tag) = match name.trim().strip_prefix("og:") {
1502+ Some(property) => (&mut ctx.og_tags, (property.to_string(), value)),
1503+ None => (&mut ctx.meta_tags, (name.trim().to_string(), value)),
1505+ if !tags.contains(&tag) {
1508+ ctx.head_at.get_or_insert(line_num);
1513+ let text = verbatim_content(node);
1514+ if !text.trim().is_empty() {
1515+ ctx.head_blocks.push(text.trim().to_string());
1516+ ctx.head_at.get_or_insert(line_num);
1523+ let text = verbatim_content(node);
1524+ // Only the @style at the top of a function's body is
1525+ // scoped; anywhere else `&` is `:scope`, the whole page
1526+ if has_top_level_ampersand(&text) {
1527+ ctx.push_once(Diagnostic::warning(
1528+ code::INVALID_VALUE,
1530+ "`&` in this @style is the whole page: only an @style at the top of a \
1531+ function's body is scoped to the function, with `&` its root element"
1535+ if !text.trim().is_empty() {
1536+ ctx.custom_css.push(text.trim().to_string());
561− let resolved = match &ctx.base_path {
1538+ Ok(None)
562− Some(base) => base.join(&filename),
1539+ }
563− None => PathBuf::from(&filename),
1540+
1541+ // @markdown: an indented block, or a file
1542+ ("markdown", DirectiveArgs::Text(file)) => {
1543+ let Some(file) = file else {
1544+ let md_lines: Vec<String> = verbatim_text(&node.children)
1548+ return Ok(Some(vec![Node::Raw(markdown_to_html(&md_lines))]));
565− match std::fs::read_to_string(&resolved) {
1550+ let filename = ctx.interpolate_text(&file.raw, line_num, Some(file.span.column));
566− Ok(text) => {
1551+ let resolved = ctx.resolve(&filename);
567− ctx.included_files.push(resolved);
1552+ let md_text = match ctx.read_file(&resolved) {
568− (text, format!("'{}'", filename))
1553+ Ok(text) => text,
570 Err(e) => {
1554 Err(e) => {
571− ctx.diagnostics.push(Diagnostic {
1555+ ctx.diagnostics.push(
572− line: line_num,
1556+ Diagnostic::error(
573− column: None,
1557+ code::UNREADABLE_FILE,
574− message: format!("cannot load data '{}': {}", filename, e),
1558+ line_num,
575− severity: Severity::Error,
1559+ format!("cannot read markdown '{}': {}", filename, e),
576− source_line: Some(content.clone()),
1560+ )
577− });
1561+ .source(content.clone()),
578 return Ok(None);
1563 return Ok(None);
581− };
1566+ ctx.included_files.push(resolved);
582− match parse_json_with_error(&json_text) {
1567+ let md_lines: Vec<String> = md_text.lines().map(|l| l.to_string()).collect();
583− Ok(json) => flatten_json(&prefix, &json, &mut ctx.variables),
1568+ Ok(Some(vec![Node::Raw(markdown_to_html(&md_lines))]))
584− Err(detail) => ctx.diagnostics.push(Diagnostic {
587− message: format!("invalid JSON in {}: {}", source, detail),
588− severity: Severity::Error,
589− source_line: Some(content.clone()),
595− // --- @if / @else ---
1571+ ("include", DirectiveArgs::Text(Some(path))) => {
1572+ self.eval_include(node.id, path, line_num, content, ctx)
597− if content.trim() == "@else" || content.trim().starts_with("@else if ") {
1575+ ("data", DirectiveArgs::Data { name, source, .. }) => {
598− return Err(ParseError {
1576+ self.eval_data(name, source, line_num, content, ctx);
599− line: line_num,
1577+ Ok(None)
600− message: "@else without matching @if".to_string(),
1578+ }
604− // --- @each loop ---
1580+ // @raw: the rest of its line, or its indented body, verbatim
1582+ let text = verbatim_content(node);
1583+ let text = text.trim_end_matches('\n');
1584+ Ok((!text.is_empty()).then(|| vec![Node::Raw(text.to_string())]))
606− // @raw: its indented body, or the rest of the line, verbatim
1587+ // A header with a syntax error (reported), or a directive
607− if content == "@raw" {
1588+ // without its argument
608− let text = block_text(children);
1589+ _ => Ok(None),
609− let text = text.trim_end_matches('\n');
610− return Ok((!text.is_empty()).then(|| vec![Node::Raw(text.to_string())]));
612− if let Some(rest) = content.strip_prefix("@raw ") {
613− return Ok(Some(vec![Node::Raw(rest.to_string())]));
616− // --- Function call ---
1593+ fn eval_include(
1596+ path: &syntax::Arg,
1599+ ctx: &mut ParseContext,
1600+ ) -> Result<Option<Vec<Node>>, ParseError> {
1601+ let (filename, column) = match path.raw.strip_prefix('"').and_then(|f| f.strip_suffix('"'))
1603+ Some(quoted) => (quoted, path.span.column + 1),
1604+ None => (path.raw.as_str(), path.span.column),
1606+ let filename = ctx.interpolate_text(filename, line_num, Some(column));
1607+ let resolved = ctx.resolve(&filename);
1609+ if ctx.include_stack.contains(&resolved) {
1610+ let cycle_chain = format_include_chain(&ctx.include_stack);
1611+ ctx.diagnostics.push(
1613+ code::CIRCULAR_INCLUDE,
1616+ "circular include '{}' (cycle: {} → {})",
1617+ filename, cycle_chain, filename
618− if content.starts_with('@') {
1625+ let imported_text = match ctx.read_file(&resolved) {
619− let name = extract_element_name(&content);
1626+ Ok(text) => text,
620− if ctx.functions.contains_key(name) {
1627+ Err(e) => {
621− ctx.used_functions.insert(name.to_string());
1628+ ctx.diagnostics.push(
622− let nodes = self.expand_fn_call(name, &content, children, line_num, ctx)?;
1629+ Diagnostic::error(
623− return Ok(Some(nodes));
1630+ code::UNREADABLE_FILE,
1632+ format!("cannot include '{}': {}", filename, e),
1640+ ctx.included_files.push(resolved.clone());
1641+ ctx.include_stack.push(resolved.clone());
1642+ let saved_base = ctx.base_path.clone();
1643+ ctx.base_path = resolved.parent().map(|p| p.to_path_buf());
1645+ let diag_count_before = ctx.diagnostics.len();
1646+ let import_chain = format_include_chain(&ctx.include_stack);
1647+ let tree = ctx.parse_tree(&imported_text);
1648+ ctx.diagnostics.extend(tree.diagnostics.iter().cloned());
1649+ ctx.trees.push((tree.clone(), Some(import_chain.clone())));
1650+ let files = Rc::make_mut(&mut ctx.included_by).entry(id).or_default();
1651+ if !files.iter().any(|(_, chain)| *chain == import_chain) {
1652+ files.push((tree.clone(), import_chain.clone()));
1654+ let saved_file = ctx.current_file.replace(import_chain.clone());
1655+ let defined_before: HashSet<String> = ctx
1658+ .chain(ctx.define_lines.keys())
1659+ .chain(ctx.fn_lines.keys())
1662+ let included_nodes = self.eval_block(&tree.nodes, ctx);
1663+ ctx.current_file = saved_file;
1664+ // An included file's definitions aren't reported unused here, where
1665+ // their lines aren't this file's: a library's are there to be
1666+ // picked from, and any other file reports its own when checked
1667+ let keep = |name: &String, _: &mut usize| defined_before.contains(name);
1668+ ctx.let_lines.retain(keep);
1669+ ctx.define_lines.retain(keep);
1670+ ctx.fn_lines.retain(keep);
1672+ // Annotate new diagnostics with import chain
1673+ for d in &mut ctx.diagnostics[diag_count_before..] {
1674+ d.message = format!("{}\n in {}", d.message, import_chain);
627− // --- Elements ---
1677+ ctx.base_path = saved_base;
1678+ ctx.include_stack.pop();
1679+ Ok(Some(included_nodes))
629− if content.starts_with('@') {
1682+ /// @data $name file.json values as $name.key
630− let node = self.parse_element_line(&content, children, line_num, ctx)?;
1683+ /// @data $name dir/*.json a list of the files' records
631− return Ok(Some(vec![inline_svg(node, line_num, ctx)]));
1684+ /// @data $name [...] / {...} inline JSON
1685+ /// @data $name env:NAME [DEFAULT] an environment variable
1689+ source: &syntax::Arg,
1692+ ctx: &mut ParseContext,
1694+ let prefix = prefix.to_string();
1695+ let filename = source.raw.as_str();
1696+ if let Some(env) = filename.strip_prefix("env:") {
1697+ let (var, default) = match env.split_once(char::is_whitespace) {
1698+ Some((var, default)) => (var, Some(default.trim())),
1699+ None => (env, None),
1701+ let default_column = default.map(|d| source.span.column + filename.len() - d.len());
1702+ let value = std::env::var(var)
1704+ .or_else(|| default.map(|d| ctx.interpolate_text(d, line_num, default_column)));
1705+ if value.is_none() {
1706+ ctx.diagnostics.push(
1707+ Diagnostic::warning(
1708+ code::UNSET_ENVIRONMENT,
1711+ "environment variable '{}' is not set and has no default",
1718+ ctx.bind(&prefix, Value::Str(value.unwrap_or_default()));
634− // --- Bare text ---
1722+ // Inline JSON: @data $links [{"label": "Home", "url": "/"}]
635−
1723+ let (json_text, source) = if filename.starts_with(['[', '{']) {
636− let var_warnings = check_undefined_vars(
1724+ (filename.to_string(), "the inline data".to_string())
637− &protect_escapes(&content),
1725+ } else {
638− &ctx.variables,
1726+ let filename = ctx.interpolate_text(filename, line_num, Some(source.span.column));
639− line_num,
1727+ if filename.contains('*') {
640− current_indent,
1728+ self.load_data_glob(&prefix, &filename, line_num, content, ctx);
642− ctx.diagnostics.extend(var_warnings);
1730+ }
643− track_var_refs(&content, &mut ctx.used_variables);
1731+ let resolved = ctx.resolve(&filename);
644− let segments = parse_text_segments(&content, ctx);
1732+ match std::fs::read_to_string(&resolved) {
645− Ok(Some(vec![Node::Text(segments)]))
1733+ Ok(text) => {
1734+ ctx.included_files.push(resolved);
1735+ (text, format!("'{}'", filename))
1738+ ctx.diagnostics.push(
1740+ code::UNREADABLE_FILE,
1742+ format!("cannot load data '{}': {}", filename, e),
1750+ match parse_json_with_error(&json_text) {
1751+ Ok(json) => ctx.bind(&prefix, json_value(json)),
1752+ Err(detail) => ctx.diagnostics.push(
1754+ code::INVALID_JSON,
1756+ format!("invalid JSON in {}: {}", source, detail),
648 /// `@data $name dir/*.json`: a list with one record per matching file
1763 /// `@data $name dir/*.json`: a list with one record per matching file
@@ -676,13 +1791,15 @@ impl Evaluator {
677 .collect(),
1792 .collect(),
678 Err(e) => {
1793 Err(e) => {
679− ctx.diagnostics.push(Diagnostic {
1794+ ctx.diagnostics.push(
680− line: line_num,
1795+ Diagnostic::new(
681− column: None,
1796+ code::UNREADABLE_FILE,
682− message: format!("cannot read directory for '{}': {}", pattern, e),
1797+ Severity::Error,
683− severity: Severity::Error,
1798+ line_num,
684− source_line: Some(content.to_string()),
1799+ format!("cannot read directory for '{}': {}", pattern, e),
1801+ .source(content.to_string()),
@@ -697,13 +1814,15 @@ impl Evaluator {
697 let text = match std::fs::read_to_string(&file) {
1814 let text = match std::fs::read_to_string(&file) {
698 Ok(text) => text,
1815 Ok(text) => text,
699 Err(e) => {
1816 Err(e) => {
700− ctx.diagnostics.push(Diagnostic {
1817+ ctx.diagnostics.push(
701− line: line_num,
1818+ Diagnostic::new(
702− column: None,
1819+ code::UNREADABLE_FILE,
703− message: format!("cannot load data '{}': {}", file.display(), e),
1820+ Severity::Error,
704− severity: Severity::Error,
1821+ line_num,
705− source_line: Some(content.to_string()),
1822+ format!("cannot load data '{}': {}", file.display(), e),
1824+ .source(content.to_string()),
707 continue;
1826 continue;
@@ -714,253 +1833,424 @@ impl Evaluator {
715 records.push(JsonValue::Object(pairs));
1834 records.push(JsonValue::Object(pairs));
717− Ok(_) => ctx.diagnostics.push(Diagnostic {
1836+ Ok(_) => ctx.diagnostics.push(
718− line: line_num,
1837+ Diagnostic::new(
719− column: None,
1838+ code::INVALID_JSON,
720− message: format!("'{}' should hold a JSON object", file.display()),
1839+ Severity::Error,
721− severity: Severity::Error,
1840+ line_num,
722− source_line: Some(content.to_string()),
1841+ format!("'{}' should hold a JSON object", file.display()),
724− Err(detail) => ctx.diagnostics.push(Diagnostic {
1843+ .source(content.to_string()),
725− line: line_num,
1844+ ),
726− column: None,
1845+ Err(detail) => ctx.diagnostics.push(
727− message: format!("invalid JSON in '{}': {}", file.display(), detail),
1846+ Diagnostic::new(
728− severity: Severity::Error,
1847+ code::INVALID_JSON,
729− source_line: Some(content.to_string()),
1848+ Severity::Error,
1850+ format!("invalid JSON in '{}': {}", file.display(), detail),
1852+ .source(content.to_string()),
732 ctx.included_files.push(file);
1855 ctx.included_files.push(file);
734− flatten_json(name, &JsonValue::Array(records), &mut ctx.variables);
1857+ ctx.bind(name, json_value(JsonValue::Array(records)));
737− /// `@each $item in LIST` or `@each $item, $index in LIST`. A LIST from
1860+ /// `@each $item in LIST` or `@each $item, $index in LIST`, with the
738− /// JSON binds each record or value to `$item`; any other list is text,
1861+ /// `@else` that follows it. LIST is a value (see
739− /// split on commas, or a range `A..B [step N]`.
1862+ /// [`ParseContext::slot_value`]): a list written with commas, a range,
1863+ /// or one `$name` or `${...}` that holds a list. Each item is bound
1864+ /// whole to `$item`, and each iteration is a block of its own.
740 fn eval_each(
1865 fn eval_each(
741 &mut self,
1866 &mut self,
742− header: &str,
1867+ node: &syntax::Node,
743− body: &[Syntax],
1868+ empty_branch: Option<&syntax::Node>,
746 ctx: &mut ParseContext,
1869 ctx: &mut ParseContext,
747− ) -> Result<Vec<Node>, ParseError> {
1870+ ) -> Result<Option<Vec<Node>>, ParseError> {
748− let Some((names, list_src)) = header.split_once(" in ") else {
1871+ ctx.visited.insert(node.id);
749− return Err(ParseError {
1872+ if let Some(branch) = empty_branch {
750− line: line_num,
1873+ ctx.visited.insert(branch.id);
751− message: "@each requires: @each $item in LIST".to_string(),
754− let names: Vec<&str> = names
756− .map(|v| v.trim().trim_start_matches('$'))
758− if names.len() > 2 {
759− return Err(ParseError {
761− message: "@each takes `$item` or `$item, $index`: to loop over records, \
762− load them with @data and use `$item.key`"
766− let (item, index) = (names[0], names.get(1).copied());
1875+ ctx.enter(node);
767− let list_src = list_src.trim();
1876+ // A malformed header is a syntax error, already reported
768− track_var_refs(list_src, &mut ctx.used_variables);
1877+ let Some(DirectiveArgs::Each(header)) = node.directive().map(|d| &d.args) else {
769−
1878+ return Ok(None);
770− // A list loaded from JSON, by name
1879+ };
771− let data_list = list_src.strip_prefix('$').and_then(|name| {
1880+ let body = &node.children;
772− let len = ctx
1881+ let empty: &[syntax::Node] = empty_branch.map_or(&[], |b| &b.children);
773− .variables
1882+ let (item, index) = (header.item.as_str(), header.index.as_deref());
774− .get(&format!("{}#", name))?
1883+ let list = &header.list;
775− .parse::<usize>()
1884+ // `[...]` is an attribute list or JSON elsewhere, not a list here
776− .ok()?;
1885+ let bracketed = list.raw.starts_with('[') && list.raw.ends_with(']');
777− Some((name.to_string(), len))
1886+ let (source, filled) = match bracketed {
778− });
1887+ true => (Value::empty(), false),
779− let undefined = list_src.strip_prefix('$').filter(|name| {
1888+ false => ctx.slot_value(&list.raw, list.span.line, Some(list.span.column)),
780− name.chars()
1889+ };
781− .all(|c| c.is_alphanumeric() || matches!(c, '_' | '-' | '.'))
1890+ let not_a_list = |message: String, ctx: &ParseContext| {
782− && !ctx.variables.contains_key(*name)
1891+ let diagnostic = Diagnostic::error(code::INVALID_LOOP, list.span.line, message)
783− });
1892+ .column(list.span.column)
784− let text_items: Vec<String> = match (&data_list, undefined) {
1893+ .subject(list.raw.as_str());
785− (Some(_), _) => Vec::new(),
1894+ match &ctx.current_source {
786− // A missing variable is an empty list: quietly for a record's
1895+ (current, Some(text)) if *current == list.span.line => {
787− // missing field (`$post.tags`), with a warning otherwise
1896+ diagnostic.source(text.clone())
788− (None, Some(name)) => {
789− let root = name.split('.').next().unwrap_or(name);
790− if !ctx.variables.contains_key(root) {
791− ctx.diagnostics.push(Diagnostic {
794− message: format!("undefined variable '${}'", name),
795− severity: Severity::Warning,
796− source_line: Some(format!("@each {}", header)),
1902+ let inner = list.raw[1..list.raw.len() - 1].trim().to_string();
1903+ let diagnostic = not_a_list(
1905+ "@each takes a list written without brackets, `@each ${} in {}`; \
1906+ JSON data goes in `@data`",
1911+ .suggest(Some(inner));
1912+ ctx.push_once(diagnostic);
1914+ let items: Vec<Value> = match source {
1915+ Value::List(list) => list.items.to_vec(),
1916+ // Reported (an undefined `$name`, brackets): there is nothing
1918+ _ if !filled => Vec::new(),
1919+ Value::Record(_) => {
1920+ let diagnostic = not_a_list(
1922+ "@each repeats for the items of a list, and `{}` is a record: \
1923+ loop over a list of records, or use its fields",
1928+ ctx.push_once(diagnostic);
799 Vec::new()
1929 Vec::new()
801− (None, None) => text_list_items(&substitute_vars(list_src, &ctx.variables)),
1931+ // Empty text (a field a record doesn't have) is no items; any
1932+ // other value is one
1933+ value if value.to_string().is_empty() => Vec::new(),
1934+ value => vec![value],
803− let count = data_list.as_ref().map_or(text_items.len(), |(_, len)| *len);
805− if body.is_empty() {
1937+ if body.iter().all(syntax::Node::is_trivia) {
806− return Ok(Vec::new());
1938+ return Ok(Some(Vec::new()));
808− if count == 0 {
1940+ if items.is_empty() {
809− return Ok(self.eval_scoped(empty, ctx));
1941+ return Ok(Some(self.eval_scoped(empty, ctx)));
811− let saved_vars = ctx.variables.clone();
812 let mut nodes = Vec::new();
1943 let mut nodes = Vec::new();
813− for i in 0..count {
1944+ for (i, value) in items.into_iter().enumerate() {
814− match &data_list {
1945+ ctx.env.push();
815− Some((name, _)) => bind_item(&mut ctx.variables, &format!("{}.{}", name, i), item),
1946+ ctx.bind(item, value);
817− let text = text_items.get(i).cloned().unwrap_or_default();
818− ctx.variables.insert(item.to_string(), text);
821 if let Some(index) = index {
1947 if let Some(index) = index {
822− ctx.variables.insert(index.to_string(), i.to_string());
1948+ ctx.bind(index, Value::Num(i as f64));
824 nodes.extend(self.eval_block(body, ctx));
1950 nodes.extend(self.eval_block(body, ctx));
826− ctx.variables = saved_vars;
1953+ Ok(Some(nodes))
830 fn define_function(
1956 fn define_function(
831 &mut self,
1957 &mut self,
832 name: &str,
1958 name: &str,
833− params: &[String],
1959+ params: &[syntax::Param],
834− defaults: &HashMap<String, String>,
1960+ node: &syntax::Node,
837 ctx: &mut ParseContext,
1961 ctx: &mut ParseContext,
1963+ let line_num = node.span.line;
1964+ let body = &node.children;
839 // An @style block at the top of the body is scoped to the
1965 // An @style block at the top of the body is scoped to the
840− // function: its rules apply inside a `.hl-NAME` wrapper.
1966+ // function: its rules apply inside a `.hl-fn-NAME` wrapper (a
841− let (style, body): (Vec<&Syntax>, Vec<&Syntax>) = body
1967+ // generated class never has a second `-`, so the two can't meet).
842− .iter()
1968+ // It is written into the page when the function is called.
843− .partition(|node| matches!(node, Syntax::Line { text, .. } if text == "@style"));
1969+ let (style, body): (Vec<&syntax::Node>, Vec<&syntax::Node>) =
844− if !style.is_empty() {
1970+ body.iter().partition(|node| node.is_directive("style"));
1971+ let scoped = (!style.is_empty()).then(|| {
845 let css: String = style
1972 let css: String = style
847− .filter_map(|node| match node {
1974+ .map(|node| {
848− Syntax::Line { children, .. } => Some(block_text(children)),
1975+ ctx.visited.insert(node.id);
849− _ => None,
1976+ verbatim_content(node)
851 .collect();
1978 .collect();
852 // Nested under the scope class, so any CSS works (multi-line
1979 // Nested under the scope class, so any CSS works (multi-line
853 // rules, at-rules)
1980 // rules, at-rules)
854− if !css.trim().is_empty() {
1981+ if css.trim().is_empty() {
855− ctx.custom_css.push(format!(".hl-{} {{\n{}}}", name, css));
1982+ String::new()
1984+ format!(".hl-fn-{} {{\n{}}}", name, css)
857− ctx.scoped_functions.insert(name.to_string());
1986+ });
1988+ // A default is filled in only when a call leaves its parameter
1989+ // out, so the names in it count as used here
1990+ for default in params.iter().filter_map(|p| p.default.as_ref()) {
1991+ track_var_refs(default, &mut ctx.used_variables);
860 ctx.fn_lines.entry(name.to_string()).or_insert(line_num);
1993 ctx.fn_lines.entry(name.to_string()).or_insert(line_num);
861− ctx.functions.insert(
1994+ let wraps_itself = ElementKind::from_name(name).is_some()
862− name.to_string(),
1995+ && body.iter().any(|node| calls_unguarded(node, name));
863− FnDef {
1996+ if wraps_itself {
864− params: params.to_vec(),
1997+ ctx.push_once(
865− defaults: defaults.clone(),
1998+ Diagnostic::error(
866− body: body.into_iter().cloned().collect(),
1999+ code::RECURSIVE_CALL,
2002+ "@{0} in the body of `@let @{0}` calls the function itself, not the \
2003+ element @{0}, so it would never stop: give the function another name \
2004+ (such as @site-{0})",
2011+ for node in &body {
2012+ node.walk(&mut |node| {
2013+ if let Some(d) = marker_in_text(node) {
2018+ let body: Vec<syntax::Node> = body.into_iter().cloned().collect();
2019+ let (slots, has_children) = declared_slots(&body, ctx);
2020+ let function = Rc::new(FnDef {
2021+ params: params.to_vec(),
2023+ source: ctx.current_source.1.clone(),
2026+ file: ctx.current_file.clone(),
2030+ env: ctx.env.clone(),
2033+ ctx.defined_functions
2034+ .insert(name.to_string(), function.clone());
2035+ ctx.env.define(name, Binding::Function(function));
871− fn expand_fn_call(
2038+ /// An element line: a chain of elements and function calls, the last of
2039+ /// which gets the indented children.
872 &mut self,
2041 &mut self,
873− name: &str,
2042+ node: &syntax::Node,
874− content: &str,
2043+ element: &syntax::ElementLine,
875− children: &[Syntax],
877 ctx: &mut ParseContext,
2044 ctx: &mut ParseContext,
878 ) -> Result<Vec<Node>, ParseError> {
2045 ) -> Result<Vec<Node>, ParseError> {
879− // Recursive function cycle detection
2046+ // An unclosed attribute list is a syntax error, already reported
880− if ctx.fn_call_stack.contains(&name.to_string()) {
2047+ if element
881− return Err(ParseError {
2048+ .chain
882− line: line_num,
2049+ .iter()
883− message: format!(
2050+ .any(|h| h.attrs.as_ref().is_some_and(|a| !a.closed))
884− "recursive function call to @{} (call stack: {})",
2051+ {
885− name,
2052+ return Ok(Vec::new());
886− ctx.fn_call_stack.join(" -> ")
890− ctx.fn_call_stack.push(name.to_string());
2054+ let line_num = node.span.line;
891−
2055+ let last = element.chain.len() - 1;
892− // Parse [param value, ...] arguments
2056+ // Each head is read where it is written, left to right. The
893− let rest = &content[1 + name.len()..];
2057+ // children belong to the last one, so the chain is built right to
894− let rest = rest.trim_start();
2058+ // left, each link wrapping the next.
895−
2059+ let mut links = Vec::new();
896− let (args, trailing_text) = if rest.starts_with('[') {
2060+ for (i, head) in element.chain.iter().enumerate() {
897− parse_attr_brackets_no_validate(rest, line_num, ctx)?
2061+ let text = if i == last {
898− } else {
2062+ element.text.as_ref()
899− (Vec::new(), rest.to_string())
2063+ } else {
2066+ links.push(resolve(head, text, line_num, &node.source, ctx)?);
2068+ let calls: Vec<Option<(String, Rc<FnDef>)>> = links
2070+ .map(|link| match link {
2071+ Resolved::Call(call) => Some((call.name.clone(), call.function.clone())),
2072+ Resolved::Element(_) => None,
2075+ let mut current = self.eval_scoped(&node.children, ctx);
2076+ // After the lines under the call ran, so the files they include
2078+ check_fillers(node, element, &calls, ctx);
2079+ for link in links.into_iter().rev() {
2080+ current = self.complete(link, current, ctx)?;
902− // Clone function definition (releases borrow on ctx). If the function is
2085+ /// Give a resolved `@name` its children: an element holds them, and a
903− // missing (shouldn't normally happen — callers check ctx.functions.contains_key
2086+ /// function's body puts them where its `@children` is.
904− // first — but we avoid panicking on malformed state).
2087+ fn complete(
905− let fn_def = match ctx.functions.get(name) {
2088+ &mut self,
906− Some(def) => def.clone(),
2089+ resolved: Resolved,
907− None => {
2090+ children: Vec<Node>,
908− ctx.fn_call_stack.pop();
2091+ ctx: &mut ParseContext,
909− return Err(ParseError {
2092+ ) -> Result<Vec<Node>, ParseError> {
910− line: line_num,
2093+ match resolved {
911− message: format!("undefined function @{}", name),
2094+ Resolved::Element(mut element) => {
912− });
2095+ element.children.extend(children);
2096+ let line = element.line_num;
2097+ Ok(vec![inline_svg(Node::Element(element), line, ctx)])
914− };
2099+ Resolved::Call(call) => self.expand_fn_call(*call, children, ctx),
916− // Parse caller's children, separating named slots from default children
2103+ fn expand_fn_call(
917− let all_caller_children = self.eval_block(children, ctx);
2104+ &mut self,
2106+ all_caller_children: Vec<Node>,
2107+ ctx: &mut ParseContext,
2108+ ) -> Result<Vec<Node>, ParseError> {
2114+ text: trailing_text,
2121+ let (name, content) = (name.as_str(), content.as_str());
2123+ // Separate the caller's `@slot NAME` blocks from its other
2124+ // children. A block for a slot the function doesn't declare was
2125+ // reported where it is written (see `check_fillers`), like one
918 let mut slot_contents: HashMap<String, Vec<Node>> = HashMap::new();
2127 let mut slot_contents: HashMap<String, Vec<Node>> = HashMap::new();
919 let mut caller_children = Vec::new();
2128 let mut caller_children = Vec::new();
920 for child in all_caller_children {
2129 for child in all_caller_children {
921− if let Node::Element(ref elem) = child
2130+ if let Node::Element(elem) = child {
922− && let ElementKind::Slot(ref slot_name) = elem.kind
2131+ match elem.kind {
923− && !slot_name.is_empty()
2132+ ElementKind::Slot(slot_name) => {
924− {
2133+ slot_contents
925− slot_contents
2134+ .entry(slot_name)
926− .entry(slot_name.clone())
2135+ .or_default()
927− .or_default()
2136+ .extend(elem.children);
928− .extend(elem.children.clone());
2137+ }
2138+ kind => caller_children.push(Node::Element(Element { kind, ..elem })),
929 continue;
2140 continue;
931 caller_children.push(child);
2142 caller_children.push(child);
933 // Text after the call, as in `@card [color red] New`, is content:
2144 // Text after the call, as in `@card [color red] New`, is content:
934− // it goes first among the caller's children.
2145+ // it goes first among the caller's children, and like them it is
935− let trailing_text = trailing_text.trim();
2146+ // evaluated where the call is written.
936− if !trailing_text.is_empty() {
2147+ if let Some(text) = &trailing_text {
937− caller_children.insert(0, Node::Text(parse_text_segments(trailing_text, ctx)));
2148+ caller_children.insert(0, Node::Text(text_segments(text, ctx)));
2150+ // Content goes where the body's `@children` is: without one, it
2151+ // would be dropped
2152+ if !fn_def.has_children && !caller_children.is_empty() {
2153+ let (column, text) = match &name_at {
2154+ Some((column, text)) => (Some(*column), text.as_str()),
2155+ None => (None, content),
2157+ ctx.push_once(no_children(name, line_num, column).source(text));
940− // Save variable state, inject function parameters
2160+ if fn_def.wraps_itself {
941− let saved_vars = ctx.variables.clone();
2161+ return Ok(Vec::new());
2163+ // Only the body is inside the call, so a function may appear in the
2164+ // content its caller passes it. A function may call itself, under
2165+ // a condition that stops it; one that doesn't stop goes too deep.
2167+ return Ok(Vec::new());
2169+ if ctx.fn_call_stack.len() >= MAX_CALL_DEPTH {
2170+ ctx.too_deep = true;
2171+ return Err(too_deep(name, &ctx.fn_call_stack, line_num).source(content));
2175+ ctx.current_source.clone(),
2178+ ctx.fn_call_stack.push(name.to_string());
2180+ // The body runs where the function is defined: it sees what was
2181+ // visible there, the function itself (so it can call itself), and
2182+ // its parameters, bound by name in the order they are declared. A
2183+ // default is filled in at the call, seeing the same, with the
2184+ // parameters before it.
2185+ let caller_env = std::mem::replace(&mut ctx.env, fn_def.env.clone());
2187+ ctx.env.define(name, Binding::Function(fn_def.clone()));
942 let mut consumed = vec![false; args.len()];
2188 let mut consumed = vec![false; args.len()];
943− for (i, param) in fn_def.params.iter().enumerate() {
2189+ for param in &fn_def.params {
944− let named = args.iter().position(|a| a.key == *param);
2190+ let mut passed = None;
945− // Positional fallback, unless that argument is named for a
2191+ for (j, arg) in args.iter().enumerate() {
946− // different parameter.
2192+ if arg.key != param.name {
947− let positional = args
2193+ continue;
949− .filter(|a| !fn_def.params.contains(&a.key) && a.value.is_some())
952− .filter(|&j| args[j].value.is_some())
956− args[j].value.clone()
958− .or_else(|| fn_def.defaults.get(param).cloned())
959− .unwrap_or_default();
960− if let Some(j) = named {
961 consumed[j] = true;
2195 consumed[j] = true;
2196+ // The later one wins, as for any attribute: one written
2197+ // after a bundle overrides it, and only one written twice
2198+ // in the call's own list is reported
2199+ if passed.is_some() && written_keys.iter().filter(|k| **k == param.name).count() > 1
2202+ Diagnostic::warning(
2203+ code::DUPLICATE_ATTRIBUTE,
2206+ "parameter '{}' of @{} is passed twice: the later one wins",
2211+ .subject(param.name.as_str()),
2214+ // Written `name=value` in the call's own list is reported
2215+ // as written; this is one from a bundle
2216+ if arg.html && !written_form.contains(&arg.key) {
2217+ let value = arg.value.as_deref().unwrap_or("");
2218+ ctx.push_once(parameter_form(name, &arg.key, value, line_num).source(content));
963− ctx.variables.insert(param.clone(), value);
2222+ let value = match passed {
2223+ // A parameter's name alone is true: `@post-card [featured]`
2224+ Some(j) if args[j].value.is_none() => Value::Bool(true),
2225+ // What the call passed, with its type: a record, a list,
2227+ Some(j) => values[j].clone().unwrap_or_else(|| {
2228+ let arg = &args[j];
2229+ match &arg.quoted {
2230+ Some(quoted) => Value::Quoted(quoted.clone()),
2231+ None => Value::Str(arg.value.clone().unwrap_or_default()),
2234+ None => match ¶m.default {
2236+ let before = ctx.diagnostics.len();
2237+ let value = fill_default(&fn_def, param, default, ctx);
2238+ point_at_call(ctx, before, &fn_def, name, line_num, content);
2242+ let (column, text) = match &name_at {
2243+ Some((column, text)) => (Some(*column), text.as_str()),
2244+ None => (None, content),
2247+ missing_parameter(name, ¶m.name, line_num, column).source(text),
2253+ ctx.bind(¶m.name, value);
965 // Arguments that aren't parameters are attributes for the
2255 // Arguments that aren't parameters are attributes for the
966 // function's root element, so a function can be styled like an
2256 // function's root element, so a function can be styled like an
@@ -972,12 +2262,24 @@ impl Evaluator {
972 .map(|(a, _)| a.clone())
2262 .map(|(a, _)| a.clone())
973 .collect();
2263 .collect();
975− // Evaluate the body with the parameters in scope
2265+ // Evaluate the body with the parameters in scope, as lines of the
976− let body_nodes = self.eval_block(&fn_def.body, ctx);
2266+ // file that defines the function
2267+ let caller_file = std::mem::replace(&mut ctx.current_file, fn_def.file.clone());
2268+ let before = ctx.diagnostics.len();
2269+ let mut body_nodes = self.eval_block(&fn_def.body, ctx);
2270+ ctx.current_file = caller_file;
2271+ point_at_call(ctx, before, &fn_def, name, line_num, content);
978− // Restore variables and call stack
2273+ // Back to the caller's names and call stack
979− ctx.variables = saved_vars;
2274+ ctx.env = caller_env;
980 ctx.fn_call_stack.pop();
2275 ctx.fn_call_stack.pop();
2276+ if ctx.fn_call_stack.is_empty() {
2277+ ctx.too_deep = false;
2279+ (ctx.current_line, ctx.current_source, ctx.current_node) = caller;
2281+ // What the body wrote is the call's
2282+ belongs_to_call(&mut body_nodes, name, line_num);
982 // Replace @children with caller's children and @slot with slot content
2284 // Replace @children with caller's children and @slot with slot content
983 let mut result_nodes =
2285 let mut result_nodes =
@@ -985,10 +2287,7 @@ impl Evaluator {
986 // Attributes that aren't parameters style the function's root
2288 // Attributes that aren't parameters style the function's root
987 // element, and a scoped @style's class goes on it too.
2289 // element, and a scoped @style's class goes on it too.
988− let scope_class = ctx
2290+ let scope_class = fn_def.scoped.is_some().then(|| format!("hl-fn-{}", name));
991− .then(|| format!("hl-{}", name));
992 if !forwarded.is_empty() || scope_class.is_some() {
2291 if !forwarded.is_empty() || scope_class.is_some() {
993 let mut roots = result_nodes.iter_mut().filter_map(|n| match n {
2292 let mut roots = result_nodes.iter_mut().filter_map(|n| match n {
994 Node::Element(e) => Some(e),
2293 Node::Element(e) => Some(e),
@@ -1001,7 +2300,33 @@ impl Evaluator {
1001 let mut problems = Vec::new();
2300 let mut problems = Vec::new();
1002 match root {
2301 match root {
1003 Some(root) => {
2302 Some(root) => {
1004− root.attrs.extend(forwarded);
2303+ // A call's `class=` adds to the root's own classes
2304+ for attr in forwarded {
2305+ let existing = (attr.html && attr.key == "class")
2306+ .then(|| root.attrs.iter_mut().find(|a| a.html && a.key == "class"))
2310+ let mut value = class.value.take().unwrap_or_default();
2311+ for name in attr.value.as_deref().unwrap_or("").split_whitespace() {
2312+ if !value.split_whitespace().any(|c| c == name) {
2314+ value.push_str(name);
2317+ class.value = Some(value.trim().to_string());
2319+ None => root.attrs.push(attr),
2322+ // The scoped `@style` goes into the page once, when the
2323+ // function is first called
2324+ if let Some(css) = &fn_def.scoped
2326+ && !ctx.scoped_css.contains(css)
2328+ ctx.scoped_css.push(css.clone());
1005 if let Some(class) = scope_class {
2330 if let Some(class) = scope_class {
1006 match root.attrs.iter_mut().find(|a| a.html && a.key == "class") {
2331 match root.attrs.iter_mut().find(|a| a.html && a.key == "class") {
1007 Some(attr) => {
2332 Some(attr) => {
@@ -1013,6 +2338,7 @@ impl Evaluator {
1013 key: "class".to_string(),
2338 key: "class".to_string(),
1014 value: Some(class),
2339 value: Some(class),
1015 html: true,
2340 html: true,
@@ -1040,52 +2366,586 @@ impl Evaluator {
1042 for message in problems {
2368 for message in problems {
1043− ctx.diagnostics.push(Diagnostic {
2369+ ctx.diagnostics.push(
1044− line: line_num,
2370+ Diagnostic::error(code::NO_SINGLE_ROOT, line_num, message)
1045− column: None,
2371+ .source(content)
1046− message,
2372+ .subject(name),
1047− severity: Severity::Warning,
2373+ );
1048− source_line: Some(content.to_string()),
1053 Ok(result_nodes)
2377 Ok(result_nodes)
1056− fn parse_element_line(
2381+/// A `@name` read where it is written: a built-in element, or a call.
1057− &mut self,
2382+enum Resolved {
1058− content: &str,
2383+ Element(Element),
1059− children: &[Syntax],
2384+ Call(Box<Call>),
1060− line_num: usize,
2385+}
1061− ctx: &mut ParseContext,
2386+
1062− ) -> Result<Node, ParseError> {
2387+/// A call of a function, with its arguments evaluated where it is written.
1063− let segments = split_chain(content);
2388+struct Call {
2390+ function: Rc<FnDef>,
2391+ args: Vec<Attribute>,
2392+ /// The value of each argument that passes a parameter, with its type
2393+ /// (see [`ParseContext::slot_value`]), in the order of `args`.
2394+ values: Vec<Option<Value>>,
2395+ /// Text after the attributes, which is content.
2396+ text: Option<syntax::Text>,
2397+ /// Parameters written `name=value`, already reported.
2398+ written_form: Vec<String>,
2399+ /// The keys written in the call's own list, not from a bundle.
2400+ written_keys: Vec<String>,
2402+ /// The column of the call's name and the line it is on, for a missing
2404+ name_at: Option<(usize, String)>,
2405+ /// The line as written, for diagnostics.
2409+/// What `@name` is where it is written: a call of the function `name`
2410+/// when one is defined, else the built-in element. A whole line, each link
2411+/// of a chain and an inline element in text all resolve here.
2413+ head: &syntax::Head,
2414+ text: Option<&syntax::Text>,
2417+ ctx: &mut ParseContext,
2418+) -> Result<Resolved, ParseError> {
2419+ let Some(function) = ctx.env.function(&head.name).cloned() else {
2420+ return parse_single_element(head, text, line, ctx).map(Resolved::Element);
2422+ ctx.used_functions.insert(head.name.clone());
2423+ let params: Vec<String> = function.params.iter().map(|p| p.name.clone()).collect();
2424+ let written = head.attrs.as_ref().map_or(&[][..], |list| &list.attrs[..]);
2425+ let written_form = written_parameter_forms(&head.name, &function, written, line, ctx);
2426+ let written_keys = written.iter().map(|a| a.key.clone()).collect();
2427+ // Parameters are bound by name; every other attribute goes to the
2428+ // root element, and is checked like any attribute
2429+ let (args, values) = parse_attrs(written, line, ctx, true, ¶ms)
2432+ let name_at = name_column(head, line).zip(match &ctx.current_source {
2433+ (current, Some(text)) if *current == line => Some(text.clone()),
2436+ Ok(Resolved::Call(Box::new(Call {
2437+ name: head.name.clone(),
2441+ text: text.cloned(),
2446+ source: source.to_string(),
2450+/// A line of another file (the standard library, an included file) means
2451+/// nothing in this one: the problems reported since `before` while
2452+/// evaluating the function (its body, a default) are moved to the call.
2454+ ctx: &mut ParseContext,
2461+ if function.file == ctx.current_file {
2464+ let defined_in = function
2467+ .unwrap_or("the file being compiled");
2468+ for d in &mut ctx.diagnostics[before..] {
2469+ d.message = format!(
2470+ "{}\n in @{} (line {} of {})",
2471+ d.message, name, d.line, defined_in
2476+ d.suggestion = None;
2477+ d.source_line = Some(source.into());
2481+/// A call nested deeper than [`MAX_CALL_DEPTH`].
2482+fn too_deep(name: &str, stack: &[String], line: usize) -> Diagnostic {
2483+ let message = if stack.iter().any(|n| n == name) {
2485+ "recursive function call to @{} goes more than {} calls deep: a function that \
2486+ calls itself needs a condition that stops it (`@if`)",
2487+ name, MAX_CALL_DEPTH
2491+ "function calls nest more than {} deep at @{} (starting with {})",
2497+ .map(|n| format!("@{}", n))
2498+ .collect::<Vec<_>>()
2502+ Diagnostic::error(code::RECURSIVE_CALL, line, message).subject(name)
2505+/// Mark what a function's body wrote as the call's: it gets the call's
2506+/// line, so what is reported about it points at the call, and the name of
2507+/// the function, unless a call inside the body already claimed it.
2508+fn belongs_to_call(nodes: &mut [Node], function: &str, line: usize) {
2509+ fn claim(element: &mut Element, function: &str, line: usize) {
2510+ element.line_num = line;
2511+ element.function.get_or_insert_with(|| function.to_string());
2512+ belongs_to_call(&mut element.children, function, line);
2514+ for node in nodes {
2516+ Node::Element(element) => claim(element, function, line),
2517+ Node::Text(segments) => {
2518+ for segment in segments {
2519+ if let TextSegment::Inline(element) = segment {
2520+ claim(element, function, line);
1065− // Parse each segment into an Element
2529+/// What an inline `{@name ...}` stands for in its line of text: an
1066− let mut elements: Vec<Element> = Vec::new();
2530+/// element; the text of a function whose body is text; or, for a body with
1067− for seg in &segments {
2531+/// several roots, its nodes as a fragment.
1068− let elem = parse_single_element(seg.trim(), line_num, ctx)?;
2532+fn inline_segments(mut nodes: Vec<Node>, line: usize) -> Vec<TextSegment> {
1069− elements.push(elem);
2533+ if let [Node::Element(_)] = nodes.as_slice()
2534+ && let Some(Node::Element(element)) = nodes.pop()
2536+ return vec![TextSegment::Inline(element)];
2538+ if nodes.iter().all(|n| matches!(n, Node::Text(_))) {
2539+ let mut segments = Vec::new();
2540+ for node in nodes {
2541+ if let Node::Text(run) = node {
2542+ if !segments.is_empty() {
2543+ segments.push(TextSegment::Plain(" ".to_string()));
2545+ segments.extend(run);
2550+ vec![TextSegment::Inline(Element {
2551+ kind: ElementKind::Fragment,
1072− // Parse indented children (belong to the innermost element)
2560+/// Fill in the default of a parameter that a call leaves out, like the
1073− let children = self.eval_block(children, ctx);
2561+/// value of an attribute passed for it: variables are filled in, one
2562+/// `$name` keeps its type and one `"..."` is quoted text. It sees what the
2563+/// body sees: the names visible where the function is defined, and the
2564+/// parameters before it. Its problems are reported at the definition, once.
2567+ param: &syntax::Param,
2569+ ctx: &mut ParseContext,
2571+ // A default that uses a later parameter is an error in the
2572+ // definition; the later one isn't bound yet, so don't report it again
2576+ .skip_while(|p| p.name != param.name)
2578+ let names = interp::names(default);
2579+ if later.clone().any(|p| names.contains(&p.name.as_str())) {
2580+ return Value::empty();
2582+ let line = param.span.line;
2583+ let at_head = line == fn_def.line && fn_def.source.is_some();
2585+ at_head.then(|| param.span.column + (param.span.end - param.span.start) - default.len());
2588+ &mut ctx.current_source,
2589+ (fn_def.line, fn_def.source.clone()),
2591+ std::mem::replace(&mut ctx.current_node, fn_def.node),
2593+ let (value, _) = ctx.slot_value(default, line, column);
2594+ (ctx.current_source, ctx.current_node) = caller;
1075− // Build chain right-to-left: rightmost gets children, each wraps the next
2598+/// Read `@page`'s attribute list and title. The page is the root element,
1076− let mut current_children = children;
2599+/// and its attributes are checked like any element's: `key=value` (and a
1077− for mut elem in elements.into_iter().rev() {
2600+/// bare boolean HTML attribute) go on `<html>`, styles on `<body>`, and
1078− elem.children.extend(current_children);
2601+/// `favicon FILE` is its one word of htmlang's own.
1079− current_children = vec![Node::Element(elem)];
2602+fn read_page(
2603+ attrs: Option<&syntax::AttrList>,
2604+ title: Option<&syntax::Arg>,
2606+ ctx: &mut ParseContext,
2608+ let mut page = Page::default();
2609+ if let Some(list) = attrs {
2610+ let words: Vec<String> = crate::vocab::PAGE_WORDS
2612+ .map(|w| w.to_string())
2614+ ctx.in_page = true;
2615+ let read = parse_attr_list(&list.attrs, line, ctx, true, &words);
2616+ ctx.in_page = false;
2617+ // How many of each name have been read, to find where the next
2619+ let mut seen: HashMap<String, usize> = HashMap::new();
2621+ let boolean = attr.value.is_none()
2622+ && crate::vocab::BOOLEAN_HTML_ATTRS.contains(&attr.key.as_str());
2623+ // Where it is written, when it is written in the list itself
2624+ let nth = seen.entry(attr.key.clone()).or_default();
2628+ .filter(|token| token.key == attr.key)
2630+ .map(|token| token.span.column);
2635+ .map(|q| q.text.clone())
2636+ .or(attr.value.clone());
2637+ if !check_page_attr(&attr.key, attr.html, value.as_deref(), line, column, ctx) {
2640+ if words.contains(&attr.key) {
2641+ if page.favicon.is_some() {
2642+ let diagnostic = Diagnostic::warning(
2643+ code::DUPLICATE_ATTRIBUTE,
2645+ "duplicate attribute 'favicon': the later one wins".to_string(),
2647+ .subject("favicon");
2648+ ctx.diagnostics.push(at_attribute(diagnostic, column, ctx));
2650+ // The file itself goes into the page when it can be read
2651+ // (relative to the file); otherwise it is linked
2652+ page.favicon = value.map(|path| match std::fs::read(ctx.resolve(&path)) {
2653+ Ok(data) => crate::codegen::data_uri(&path, &data),
2656+ } else if attr.html || boolean {
2657+ page.html_attrs.push(attr);
2659+ page.styles.push(attr);
2663+ page.title = match title {
2664+ Some(title) => ctx.interpolate_text(&title.raw, title.span.line, Some(title.span.column)),
2665+ None => String::new(),
1082− current_children.into_iter().next().ok_or(ParseError {
2670+/// `@page`'s own rules for one of its attributes, checked where the
1083− line: line_num,
2671+/// `@page` runs and where it doesn't (a layout that isn't called): its
1084− message: "element chain produced no nodes (this is a parser bug)".to_string(),
2672+/// word is written `favicon FILE`, and `inline` belongs to `@image`.
1085− })
2673+/// Returns whether the attribute can be used (a `favicon` with its file,
2674+/// or any other attribute but `inline`).
2678+ value: Option<&str>,
2680+ column: Option<usize>,
2681+ ctx: &mut ParseContext,
2683+ let report = |ctx: &mut ParseContext, diagnostic: Diagnostic| {
2684+ let diagnostic = at_attribute(diagnostic, column, ctx);
2685+ ctx.diagnostics.push(diagnostic);
2687+ if crate::vocab::PAGE_WORDS.contains(&key) {
2692+ code::PARAMETER_FORM,
2695+ "'{0}' is @page's own word, not an HTML attribute: write `{0} {1}`",
2697+ value.filter(|v| !v.is_empty()).unwrap_or("FILE")
2700+ .subject(format!("{}=", key))
2701+ .suggest(Some(format!("{} ", key))),
2704+ if value.is_none_or(|v| v.trim().is_empty()) {
2708+ code::MISSING_VALUE,
2710+ format!("'{0}' needs its file: `{0} favicon.png`", key),
2718+ if !html && crate::vocab::base_attribute(key) == "inline" {
2722+ code::UNEXPECTED_ARGUMENT,
2724+ "`inline` puts an image's file into the page, and @page has none: it only \
2728+ .subject("inline"),
2735+/// A parameter passed `name=value`, the form of an HTML attribute.
2736+fn parameter_form(function: &str, key: &str, value: &str, line: usize) -> Diagnostic {
2738+ code::PARAMETER_FORM,
2741+ "'{}' is a parameter of @{}: parameters are written `name value`, so write `{} {}`",
2742+ key, function, key, value
2745+ .subject(format!("{}=", key))
2746+ .suggest(Some(format!("{} ", key)))
2749+/// A call that leaves out a parameter without a default.
2750+fn missing_parameter(
2754+ column: Option<usize>,
2756+ let diagnostic = Diagnostic::error(
2757+ code::MISSING_PARAMETER,
2760+ "@{} needs '{}': the parameter has no default, so pass it as `{} VALUE`",
2761+ function, param, param
2766+ Some(column) => diagnostic.column(column),
2767+ None => diagnostic,
2771+/// The column of a call's `@name`, when it is on the call's line.
2772+fn name_column(head: &syntax::Head, line: usize) -> Option<usize> {
2773+ (head.name_span.line == line).then_some(head.name_span.column)
2776+/// Define `$name`, or, for `--name`, the CSS custom property on `:root`
2777+/// (which gets quoted text with its quotes, and is read with
2778+/// `var(--name)`, never as a variable). `@let name.field value` gives the
2779+/// record `$name` that field (or the list `$name` a new item at that
2780+/// index), as a new value in this block.
2781+fn set_variable(name: &str, value: Value, line_num: usize, ctx: &mut ParseContext) {
2782+ if name.starts_with("--") {
2785+ .map_or_else(|| value.to_string(), str::to_string);
2786+ let at_line = |diagnostic: Diagnostic, ctx: &ParseContext| match &ctx.current_source {
2787+ (current, Some(text)) if *current == line_num => diagnostic.source(text.clone()),
2790+ // `:root` is one place for the whole page: a declaration inside a
2791+ // block (an element, a loop, a function's body) would not be
2792+ // kept to it, and each run would replace the last
2793+ if ctx.env.frames.len() > FILE_FRAMES {
2794+ let diagnostic = Diagnostic::error(
2795+ code::INVALID_DEFINITION,
2798+ "`@let {name}` declares {name} on :root, for the whole page, so it goes at \
2799+ the top level of the file: to set it on an element and what is inside \
2800+ it, write `[{name} value]` on that element"
2804+ ctx.push_once(at_line(diagnostic, ctx));
2807+ match css_breakout(&css) {
2809+ let diagnostic = Diagnostic::error(
2810+ code::INVALID_VALUE,
2813+ "the value of '{}' has {}: `{}` can't be written into the page's CSS",
2817+ .subject(css.as_str());
2818+ ctx.push_once(at_line(diagnostic, ctx));
2820+ None => match ctx.css_vars.iter_mut().find(|(n, _)| n == name) {
2821+ Some(declared) => {
2822+ let diagnostic = Diagnostic::warning(
2823+ code::DUPLICATE_ATTRIBUTE,
2826+ "{name} is declared again: :root has one value for the whole page, \
2827+ so every element gets this one, also above this line (a theme \
2828+ redefines a token on an element: `[dark:{name} {css}]`)"
2833+ ctx.push_once(at_line(diagnostic, ctx));
2835+ None => ctx.css_vars.push((name.to_string(), css)),
2840+ let mut path = name.split('.');
2841+ let root = path.next().unwrap_or(name);
2842+ let fields: Vec<&str> = path.collect();
2843+ let value = match fields.is_empty() {
2845+ false => match with_field(ctx.env.value(root).cloned(), root, &fields, value) {
2846+ Ok(value) => value,
2849+ Diagnostic::error(code::INVALID_DEFINITION, line_num, message).subject(name);
2850+ let diagnostic = match &ctx.current_source {
2851+ (current, Some(text)) if *current == line_num => {
2852+ diagnostic.source(text.clone())
2856+ ctx.push_once(diagnostic);
2857+ // Reported: the name keeps what it held
2858+ ctx.let_lines.entry(root.to_string()).or_insert(line_num);
2863+ ctx.bind(root, value);
2864+ ctx.let_lines.entry(root.to_string()).or_insert(line_num);
2867+/// `value` (the value of `$name`) with the field at `path` set to `new`:
2868+/// a record's field, or the item of a list at an index it has. A name
2869+/// without a value, or one whose value is empty (a field a record doesn't
2870+/// have), becomes a record; any other value has no fields to set.
2872+ value: Option<Value>,
2876+) -> Result<Value, String> {
2877+ let Some((field, rest)) = path.split_first() else {
2880+ let inner = format!("{}.{}", name, field);
2882+ Some(Value::Record(fields)) => {
2883+ let mut fields = fields.as_ref().clone();
2884+ match fields.iter().position(|(key, _)| key == field) {
2886+ let old = std::mem::replace(&mut fields[i].1, Value::empty());
2887+ fields[i].1 = with_field(Some(old), &inner, rest, new)?;
2889+ None => fields.push((field.to_string(), with_field(None, &inner, rest, new)?)),
2891+ Ok(Value::Record(Rc::new(fields)))
2893+ Some(Value::List(list)) => {
2894+ let count = list.items.len();
2895+ let Some(i) = field.parse::<usize>().ok().filter(|&i| i < count) else {
2896+ return Err(format!(
2897+ "`${}` is {}, so `.{}` isn't one of its items (they are `.0` to `.{}`)",
2899+ Value::List(list).describe(),
2901+ count.saturating_sub(1)
2904+ let mut items = list.items.as_ref().clone();
2905+ let old = std::mem::replace(&mut items[i], Value::empty());
2906+ items[i] = with_field(Some(old), &inner, rest, new)?;
2907+ // Its items changed, so it no longer prints as written
2908+ Ok(Value::list(items))
2910+ None => Ok(Value::Record(Rc::new(vec![(
2912+ with_field(None, &inner, rest, new)?,
2914+ Some(value) if value.to_string().is_empty() => with_field(None, name, path, new),
2915+ Some(value) => Err(format!(
2916+ "`@let {}.{}` sets a field of a record, but `${}` is {} (`{}`), which has no fields",
2926+/// What a verbatim directive holds (`@head`, `@style`, `@raw`): the rest
2927+/// of its line (`@style .a { color: red }`), or else its indented block.
2928+/// The two together are a syntax error, reported by the tree; the line
2930+fn verbatim_content(node: &syntax::Node) -> String {
2931+ match node.directive().map(|d| &d.args) {
2932+ Some(DirectiveArgs::Text(Some(line))) => format!("{}\n", line.raw),
2933+ _ => verbatim_text(&node.children),
2937+/// The text of a verbatim body (`@head`, `@style`, `@markdown`, `@raw`).
2938+fn verbatim_text(children: &[syntax::Node]) -> String {
2939+ let mut text = String::new();
2940+ for child in children {
2941+ if let NodeKind::Verbatim(body) = &child.kind {
2942+ text.push_str(&body.text);
1089// ---------------------------------------------------------------------------
2949// ---------------------------------------------------------------------------
1090// @children replacement
2950// @children replacement
1091// ---------------------------------------------------------------------------
2951// ---------------------------------------------------------------------------
@@ -1130,91 +2990,705 @@ fn replace_children_and_slots(
1132// ---------------------------------------------------------------------------
2992// ---------------------------------------------------------------------------
1133−// Element parsing
2993+// Where @slot and @children are written
1134// ---------------------------------------------------------------------------
2994// ---------------------------------------------------------------------------
1136−fn extract_element_name(content: &str) -> &str {
2996+/// The files each `@include` line brought in, by the line's node id, with
1137− let without_at = &content[1..];
2997+/// the include chain that leads to each.
1138− match without_at.find([' ', '[']) {
2998+type IncludedBy = HashMap<usize, Vec<(Rc<Tree>, String)>>;
1139− Some(i) => &without_at[..i],
2999+
1140− None => without_at,
3000+/// The lines of the files an `@include` line brings in, and the include
3001+/// chain of each (for diagnostics).
3002+type Included<'a, 'f> = &'f dyn Fn(&syntax::Node) -> Vec<(&'a [syntax::Node], Option<&'a str>)>;
3004+/// Whether `name` is a function here: defined so far, or anywhere in the
3005+/// file and the files it includes.
3006+fn is_function(name: &str, ctx: &ParseContext) -> bool {
3007+ ctx.env.function(name).is_some() || ctx.namespace.contains(name)
3010+/// Whether `name` is one slot name: letters, digits, `-` and `_`,
3011+/// starting with a letter (like a function's name).
3012+fn is_slot_name(name: &str) -> bool {
3013+ name.chars().next().is_some_and(char::is_alphabetic)
3016+ .all(|c| c.is_alphanumeric() || c == '-' || c == '_')
3019+/// What a `@slot` or `@children` line is written in.
3020+#[derive(Clone, Copy)]
3022+ /// The top of a file or of a function's body, or a built-in element
3024+ Element(Option<&'a str>),
3025+ /// A call: its content.
3029+/// Where a line is, for [`slot_uses`].
3030+#[derive(Clone, Copy)]
3032+ /// Inside a function's body.
3035+ /// Outside a body: the call (and its line) whose content it is in.
3036+ call: Option<(&'a str, usize)>,
3037+ /// The include chain of the file it is in, when that isn't the file
3038+ /// being compiled.
3039+ file: Option<&'a str>,
3043+ /// The top of a file, or of a function's body.
3044+ fn top(body: bool) -> Self {
3047+ place: Place::Element(None),
1144−fn parse_single_element(
3054+/// What [`slot_uses`] knows about the names and files it walks.
1145− content: &str,
3055+struct Scan<'a, 'f> {
1146− line_num: usize,
3056+ is_function: &'f dyn Fn(&str) -> bool,
1147− ctx: &mut ParseContext,
3057+ included: Included<'a, 'f>,
1148−) -> Result<Element, ParseError> {
3058+ /// Visit the bodies of the functions defined in the lines too.
1149− let (kind, rest) = if let Some(without_at) = content.strip_prefix('@') {
3059+ into_lets: bool,
1150− match without_at.find([' ', '[']) {
3060+}
1152− let kind_str = &without_at[..i];
3062+/// A `@slot` or `@children` written in a file, and where.
1153− let rest = if without_at.as_bytes()[i] == b'[' {
3063+struct SlotUse<'a> {
1154− without_at[i..].to_string()
3064+ node: &'a syntax::Node,
1155− } else {
3065+ head: &'a syntax::Head,
1156− without_at[i + 1..].to_string()
3066+ /// The text after it, which is a slot's name; `None` when it isn't
1157− };
3067+ /// the last head of its chain.
1158− match parse_element_kind(kind_str, line_num) {
3068+ text: Option<&'a syntax::Text>,
1159− Ok(kind) => (kind, rest),
3069+ /// Written inline in a line of text, `{@slot x}`.
1160− Err(mut e) => {
3070+ inline: bool,
1161− // Also suggest user-defined functions
3071+ at: At<'a>,
1162− if let Some(fn_suggestion) = suggest_fn_name(kind_str, ctx) {
3072+}
1164− format!("{}, or did you mean @{}?", e.message, fn_suggestion);
3074+impl SlotUse<'_> {
1165− }
3075+ fn is_slot(&self) -> bool {
1166− return Err(e);
3076+ self.head.name == "slot"
3079+ /// The slot's name as written.
3080+ fn name(&self) -> &str {
3081+ self.text.map_or("", |t| t.raw.trim())
3084+ /// A `@slot NAME` that marks a place in a function's body (not one
3085+ /// that fills a slot of a call).
3086+ fn declares(&self) -> bool {
3087+ self.is_slot() && !self.inline && !matches!(self.at.place, Place::Call)
3091+/// Where each `@slot` and `@children` in `block` is written. A `@slot`
3092+/// directly under a call (under its `@if`, `@else` and `@each` too) fills
3093+/// one of its slots; anywhere else in a function's body it declares one.
3094+/// An included file's lines are where its `@include` is.
3096+ block: &'a [syntax::Node],
3098+ scan: &Scan<'a, '_>,
3099+ out: &mut Vec<SlotUse<'a>>,
3102+ text: &'a syntax::Text,
3103+ node: &'a syntax::Node,
3105+ scan: &Scan<'a, '_>,
3106+ out: &mut Vec<SlotUse<'a>>,
3108+ for segment in &text.segments {
3109+ if let Segment::Inline(inline_element) = segment {
3110+ let head = &inline_element.head;
3111+ if matches!(head.name.as_str(), "slot" | "children")
3112+ && !(scan.is_function)(&head.name)
3117+ text: inline_element.text.as_ref(),
3122+ if let Some(text) = &inline_element.text {
3123+ inline(text, node, at, scan, out);
1170− None => match parse_element_kind(without_at, line_num) {
3126+ }
1171− Ok(kind) => (kind, String::new()),
3127+ }
1172− Err(mut e) => {
3128+ for node in block {
1173− if let Some(fn_suggestion) = suggest_fn_name(without_at, ctx) {
3129+ match &node.kind {
1174− e.message = format!("{}, or did you mean @{}?", e.message, fn_suggestion);
3130+ NodeKind::Directive(directive) => match &directive.args {
3131+ DirectiveArgs::Let(def) if matches!(def.form, LetForm::Function(_)) => {
3132+ if scan.into_lets {
3137+ slot_uses(&node.children, top, scan, out);
1176− return Err(e);
3139+ }
3140+ // A value's body is an error of its own
3141+ DirectiveArgs::Let(_) => {}
3142+ _ if directive.spec.body == BodyKind::Verbatim => {}
3143+ // `@if`, `@else` and `@each` put their lines in place, and
3144+ // `@include` its file's; the lines under a directive that
3145+ // takes no body are its siblings
3147+ for (lines, file) in (scan.included)(node) {
3148+ slot_uses(lines, At { file, ..at }, scan, out);
3150+ slot_uses(&node.children, at, scan, out);
3153+ NodeKind::Element(line) => {
3155+ let last = line.chain.len() - 1;
3156+ for (i, head) in line.chain.iter().enumerate() {
3157+ let text = if i == last { line.text.as_ref() } else { None };
3158+ let function = (scan.is_function)(&head.name);
3159+ if !function && matches!(head.name.as_str(), "slot" | "children") {
3167+ } else if let Some(text) = text {
3168+ inline(text, node, at, scan, out);
3171+ at.place = Place::Call;
3173+ at.call = Some((&head.name, node.span.line));
3176+ at.place = Place::Element(Some(&head.name));
3179+ slot_uses(&node.children, at, scan, out);
3181+ NodeKind::Text(text) => {
3182+ inline(text, node, at, scan, out);
3183+ slot_uses(&node.children, at, scan, out);
3185+ NodeKind::Blank | NodeKind::Comment | NodeKind::Verbatim(_) => {}
1181− return Err(ParseError {
3188+}
1182− line: line_num,
3189+
1183− message: format!("expected @element or [attrs], got: {}", content),
3190+/// The slots a function's body declares, and whether it has a
3191+/// `@children`, when it is defined. The files its `@include` lines bring
3192+/// in count too: they are read now, since they run only at a call.
3193+fn declared_slots(body: &[syntax::Node], ctx: &mut ParseContext) -> (Vec<String>, bool) {
3194+ let mut files = HashMap::new();
3197+ ctx.base_path.clone(),
3202+ let included = |node: &syntax::Node| match files.get(&node.id) {
3203+ Some(tree) => vec![(&tree.nodes[..], None)],
3204+ None => Vec::new(),
3206+ let is_function = |name: &str| is_function(name, ctx);
3207+ slots_of(body, &is_function, &included)
3210+/// Read and parse the files the `@include` lines in `nodes` bring in (by
3211+/// a literal path, relative to `base`), and the files those include, by
3212+/// the node id of each `@include` line.
3214+ nodes: &[syntax::Node],
3215+ base: Option<PathBuf>,
3216+ stack: &mut Vec<PathBuf>,
3217+ ctx: &mut ParseContext,
3218+ files: &mut HashMap<usize, Rc<Tree>>,
3220+ let mut includes = Vec::new();
3221+ for node in nodes {
3222+ node.walk(&mut |node| {
3223+ if let Some(DirectiveArgs::Text(Some(path))) = node.directive().map(|d| &d.args)
3224+ && node.is_directive("include")
3226+ includes.push((node.id, path.raw.clone()));
3230+ for (id, path) in includes {
3231+ let path = path.trim_matches('"');
3232+ if path.contains('$') {
3235+ let resolved = match &base {
3236+ Some(base) => base.join(path),
3237+ None => PathBuf::from(path),
3239+ if stack.contains(&resolved) {
3242+ let Ok(text) = ctx.read_file(&resolved) else {
3245+ let tree = ctx.parse_tree(&text);
3246+ stack.push(resolved.clone());
3247+ let parent = resolved.parent().map(Path::to_path_buf);
3248+ read_includes(&tree.nodes, parent, stack, ctx, files);
3250+ files.insert(id, tree);
3254+/// The slots a function's body declares (`@slot NAME`, in order), and
3255+/// whether it has a `@children` for the content of a call. A `@slot`
3256+/// directly under a call in the body fills that call's slot instead, so
3257+/// `is_function` says which names are functions. The files the body
3258+/// includes aren't read.
3259+pub fn function_slots(
3260+ body: &[syntax::Node],
3261+ is_function: &dyn Fn(&str) -> bool,
3262+) -> (Vec<String>, bool) {
3263+ slots_of(body, is_function, &|_| Vec::new())
3267+ body: &'a [syntax::Node],
3268+ is_function: &dyn Fn(&str) -> bool,
3269+ included: Included<'a, '_>,
3270+) -> (Vec<String>, bool) {
3276+ let mut uses = Vec::new();
3277+ slot_uses(body, At::top(true), &scan, &mut uses);
3278+ let mut slots: Vec<String> = Vec::new();
3279+ for slot in uses.iter().filter(|u| u.declares()) {
3280+ let name = slot.name();
3281+ if is_slot_name(name) && !slots.iter().any(|s| s == name) {
3282+ slots.push(name.to_string());
3285+ let has_children = uses.iter().any(|u| !u.is_slot() && !u.inline);
3286+ (slots, has_children)
3289+/// The line as written, indented, when it is one physical line, so a
3290+/// column points into it.
3291+fn written_line(node: &syntax::Node) -> String {
3292+ match node.line_count <= 1 {
3293+ true => format!("{}{}", " ".repeat(node.indent), node.source),
3294+ false => node.source.clone(),
3298+/// The lines of the files an `@include` line brought in when it ran, from
3300+fn ran_includes<'a>(
3301+ included_by: &'a IncludedBy,
3302+ node: &syntax::Node,
3303+) -> Vec<(&'a [syntax::Node], Option<&'a str>)> {
3304+ match included_by.get(&node.id) {
3305+ Some(files) => files
3307+ .map(|(tree, chain)| (&tree.nodes[..], Some(chain.as_str())))
3309+ None => Vec::new(),
3313+/// Check where every `@slot` and `@children` of the file and the files it
3314+/// includes is written, whether or not it runs: a slot has one name, a
3315+/// function's body marks places with them, and a call fills its slots
3316+/// with `@slot` blocks directly under it. An included file's lines are
3317+/// where its `@include` is (in a body, under a call), so an `@include`
3318+/// that never ran leaves its file unchecked.
3319+fn check_slot_places(ctx: &mut ParseContext) {
3320+ let trees = std::mem::take(&mut ctx.trees);
3321+ let included_by = ctx.included_by.clone();
3322+ let is_function = |name: &str| is_function(name, ctx);
3324+ is_function: &is_function,
3325+ included: &|node| ran_includes(&included_by, node),
3328+ let mut uses = Vec::new();
3329+ for (tree, _) in trees.iter().filter(|(_, chain)| chain.is_none()) {
3330+ slot_uses(&tree.nodes, At::top(false), &scan, &mut uses);
3332+ let found: Vec<Diagnostic> = uses
3334+ .filter_map(|slot| {
3335+ let mut d = slot_problem(slot)?;
3336+ if d.column.is_none() {
3337+ d = d.column(slot.head.name_span.column);
3339+ d = d.source(written_line(slot.node));
3340+ if let Some(file) = slot.at.file {
3341+ d.message = format!("{}\n in {}", d.message, file);
3346+ ctx.diagnostics.extend(found);
1187− // Parse optional [attrs]
3350+/// What is wrong with a `@slot` or `@children` where it is written.
1188− let (attrs, rest) = if rest.starts_with('[') {
3351+fn slot_problem(slot: &SlotUse) -> Option<Diagnostic> {
1189− parse_attr_brackets(&rest, line_num, ctx)?
3352+ let line = slot.node.span.line;
3353+ let what = if slot.is_slot() {
3354+ match slot.name() {
3355+ "" => "@slot".to_string(),
3356+ name => format!("@slot {}", name),
1190 } else {
3358 } else {
1191− (Vec::new(), rest)
3359+ "@children".to_string()
3362+ return Some(Diagnostic::error(
3363+ code::MISPLACED_SLOT,
3366+ "{} goes on a line of its own: inline in text it marks and fills nothing",
3371+ if let Some(list) = &slot.head.attrs {
3374+ code::UNEXPECTED_ARGUMENT,
3377+ "{} takes no attributes: it is replaced by content, so style the \
3378+ element around it",
3382+ .column(list.span.column),
3385+ if slot.is_slot() {
3386+ let name = slot.name();
3387+ if name.is_empty() {
3388+ return Some(Diagnostic::error(
3389+ code::MISSING_ARGUMENT,
3391+ "@slot needs a name: `@slot footer` (the caller's content without a \
3392+ name goes where `@children` is)"
3396+ if !is_slot_name(name) {
3397+ let joined = name.split_whitespace().collect::<Vec<_>>().join("-");
3398+ let suggestion = is_slot_name(&joined).then_some(joined);
3399+ let column = slot.text.map(|t| t.span.column);
3400+ let d = Diagnostic::error(
3401+ code::INVALID_SLOT_NAME,
3404+ "'{}' is not a slot name: a slot's name is one word of letters, digits, \
3405+ `-` and `_`, starting with a letter, and its content goes on the lines \
3411+ .suggest(suggestion);
3412+ return Some(match column {
3413+ Some(column) => d.column(column),
3417+ if matches!(slot.at.place, Place::Call) || slot.at.body {
3420+ let message = match (slot.at.call, slot.at.place) {
3421+ (Some((call, call_line)), Place::Element(Some(element))) => format!(
3422+ "{} is inside @{}, so it fills nothing: a @slot block that fills a slot of \
3423+ @{} (line {}) goes directly under the call",
3424+ what, element, call, call_line
3427+ "{} is outside a function's body: `@slot NAME` marks a place in a body \
3428+ (`@let @name`), and directly under a call it fills one",
3432+ return Some(Diagnostic::error(code::MISPLACED_SLOT, line, message));
3437+ let message = match slot.at.call {
3438+ Some((call, _)) => format!(
3439+ "@children is outside a function's body, so it stands for nothing: the content \
3440+ for @{} is written directly under the call",
3443+ None => "@children is outside a function's body: it marks where a body puts the \
3444+ content of each call"
3447+ Some(Diagnostic::error(code::MISPLACED_SLOT, line, message))
1194− let rest = rest.trim().to_string();
3450+/// A `@slot NAME` block that fills a slot of a call.
1195− track_var_refs(&rest, &mut ctx.used_variables);
3451+struct Filler<'a> {
3452+ node: &'a syntax::Node,
3453+ text: &'a syntax::Text,
3454+ /// The include chain of the file it is in, when that isn't the file
3455+ /// being compiled.
3456+ file: Option<&'a str>,
1197− // For @link, first token of rest is URL, remainder is inline text
3459+/// Whether `@slot` is the built-in element here, and not a function
1198− let mut children = Vec::new();
3460+/// defined so far that took its name.
1199− let argument = if rest.is_empty() {
3461+fn slot_is_built_in(ctx: &ParseContext) -> bool {
1200− None
3462+ ctx.env.function("slot").is_none()
1201− } else if kind == ElementKind::Link {
3463+}
1202− let rest_sub = substitute_vars(&protect_escapes(&rest), &ctx.variables);
3464+
1203− if let Some((url, text)) = rest_sub.split_once(' ') {
3465+/// The `@slot NAME` blocks directly under a call, in `block` (under its
1204− let text = text.trim();
3466+/// `@if`, `@else` and `@each` too, and in the files its `@include` lines
1205− if !text.is_empty() {
3467+/// brought in).
1206− children.push(Node::Text(parse_text_segments(text, ctx)));
3468+fn fillers<'a>(
1207− }
3469+ block: &'a [syntax::Node],
1208− Some(restore_escapes(url))
3470+ file: Option<&'a str>,
1209− } else {
3471+ included: &'a IncludedBy,
1210− Some(restore_escapes(&rest_sub))
3472+ out: &mut Vec<Filler<'a>>,
3474+ for node in block {
3476+ NodeKind::Directive(directive)
3477+ if matches!(directive.name(), "if" | "else" | "each") =>
3479+ fillers(&node.children, file, included, out);
3481+ NodeKind::Directive(directive) if directive.name() == "include" => {
3482+ for (lines, file) in ran_includes(included, node) {
3483+ fillers(lines, file, included, out);
3486+ NodeKind::Element(line) if line.chain.len() == 1 && line.chain[0].name == "slot" => {
3487+ if let Some(text) = &line.text {
3488+ out.push(Filler { node, text, file });
1213− Some(restore_escapes(&substitute_vars(
3494+}
1214− &protect_escapes(&rest),
3495+
1215− &ctx.variables,
3496+/// Whether `block`, the lines under a call, holds content other than
1216− )))
3497+/// `@slot` blocks (under `@if`, `@else` and `@each` too): text, an
3498+/// element, raw HTML, Markdown or an included file. For code that doesn't
3500+fn holds_content(block: &[syntax::Node], ctx: &ParseContext) -> bool {
3501+ block.iter().any(|node| match &node.kind {
3502+ NodeKind::Directive(directive) => match directive.name() {
3503+ "if" | "else" | "each" => holds_content(&node.children, ctx),
3504+ name => matches!(name, "raw" | "markdown" | "include"),
3506+ NodeKind::Element(line) => {
3507+ line.chain[0].name != "slot" || !slot_is_built_in(ctx) || line.chain.len() > 1
3509+ NodeKind::Text(_) => true,
3514+/// Check the `@slot NAME` blocks passed to each call of a line against
3515+/// the slots its function declares. `calls` has the function of each head
3516+/// of the chain that is a call.
3518+ node: &syntax::Node,
3519+ element: &syntax::ElementLine,
3520+ calls: &[Option<(String, Rc<FnDef>)>],
3521+ ctx: &mut ParseContext,
3523+ if !slot_is_built_in(ctx) {
3526+ let included = ctx.included_by.clone();
3527+ let last = element.chain.len() - 1;
3528+ for (i, call) in calls.iter().enumerate() {
3529+ let Some((name, function)) = call else {
3532+ let mut found = Vec::new();
3534+ fillers(&node.children, None, &included, &mut found);
3535+ } else if i + 1 == last
3536+ && element.chain[last].name == "slot"
3537+ && let Some(text) = &element.text
3539+ // `@card > @slot footer`
3540+ found.push(Filler {
3546+ for filler in found {
3547+ let slot = filler.text.raw.trim();
3548+ if !is_slot_name(slot) || function.slots.iter().any(|s| s == slot) {
3551+ let mut d = unknown_slot(name, slot, &function.slots, filler.text.span.line)
3552+ .column(filler.text.span.column)
3553+ .source(written_line(filler.node));
3554+ if let Some(file) = filler.file {
3555+ d.message = format!("{}\n in {}", d.message, file);
3562+/// A `@slot NAME` block for a slot the function doesn't declare.
3563+fn unknown_slot(function: &str, slot: &str, slots: &[String], line: usize) -> Diagnostic {
3564+ let candidates: Vec<&str> = slots.iter().map(String::as_str).collect();
3565+ let suggestion = suggest_closest(slot, &candidates);
3566+ let message = match (slots.is_empty(), suggestion) {
3567+ (true, _) => format!(
3568+ "@{} has no slot '{}': its body declares no slots (`@slot NAME`)",
3571+ (false, Some(close)) => format!(
3572+ "@{} has no slot '{}', did you mean '{}'? (its slots: {})",
3578+ (false, None) => format!(
3579+ "@{} has no slot '{}' (its slots: {})",
3585+ Diagnostic::error(code::UNKNOWN_SLOT, line, message)
3587+ .suggest(suggestion)
3590+/// Content passed to a function whose body has no `@children`.
3591+fn no_children(function: &str, line: usize, column: Option<usize>) -> Diagnostic {
3592+ let d = Diagnostic::error(
3593+ code::UNEXPECTED_CONTENT,
3596+ "@{0} takes no content: its body has no `@children`, so the text and lines \
3597+ passed to it would be dropped (pass text as a parameter, `@{0} [name value]`, \
3598+ or add `@children` to the body)",
3602+ .subject(function);
3604+ Some(column) => d.column(column),
3609+// ---------------------------------------------------------------------------
3611+// ---------------------------------------------------------------------------
3613+/// Build the element for `@name [attrs] text` (on its own line, in a chain,
3614+/// or inline in text).
3615+fn parse_single_element(
3616+ head: &syntax::Head,
3617+ text: Option<&syntax::Text>,
3619+ ctx: &mut ParseContext,
3620+) -> Result<Element, ParseError> {
3621+ let kind = parse_element_kind(&head.name, line_num, ctx)?;
3622+ let mut attrs = head.attrs.as_ref().map_or_else(Vec::new, |list| {
3623+ parse_attr_list(&list.attrs, line_num, ctx, true, &[])
3626+ // The leading argument: for an element whose row names a leading
3627+ // attribute (`@link`'s href, `@image`'s src, `@form`'s action, ...),
3628+ // the first token of the text fills it, split before anything is
3629+ // filled in, and the rest is content (an error on an element without
3630+ // content). `@slot`'s whole text is its name. Any other element's text
3631+ // is content, parsed like any line of text, as in `@el [padding 8]
3632+ // Hello` or `@h2 Meet {@text htmlang}`; its layout decides how it
3633+ // combines with the lines under it.
3634+ let mut children = Vec::new();
3635+ let mut argument = None;
3636+ let leading = kind.arg().attributes();
3638+ Some(text) if !leading.is_empty() => {
3639+ let (token, rest) = text.split_leading();
3642+ .find(|a| a.html && leading.contains(&a.key.as_str()))
3643+ .map(|a| (a.key.clone(), a.value.clone().unwrap_or_default()));
3644+ if let Some((key, value)) = given {
3645+ // The attribute wins; the text is content, as if the
3646+ // element had no leading argument
3647+ ctx.push_once(leading_twice(&kind, &token, &key, &value, text, ctx));
3648+ if !takes_no_text(&kind) {
3649+ children.push(Node::Text(text_segments(text, ctx)));
3651+ } else if let Some(d) = bad_leading_token(&kind, &token, &text.raw, ctx) {
3652+ // Nothing is taken as the argument; the line is content
3654+ if !takes_no_text(&kind) {
3655+ children.push(Node::Text(text_segments(text, ctx)));
3658+ let column = Some(token.span.column);
3660+ ctx.fill_value(&token.raw, text.span.line, column, Sink::Text)
3663+ if let Some(rest) = rest {
3664+ if let Some(d) = chain_after_argument(&kind, &token.raw, &rest, ctx) {
3667+ if takes_no_text(&kind) {
3668+ let d = after_the_leading_argument(&kind, &token.raw, &rest);
3669+ let d = at_attribute(d, Some(rest.span.column), ctx);
3672+ children.push(Node::Text(text_segments(&rest, ctx)));
3677+ Some(text) if matches!(kind, ElementKind::Slot(_)) => {
3679+ Some(ctx.interpolate_text(&text.raw, text.span.line, Some(text.span.column)));
3681+ Some(text) => children.push(Node::Text(text_segments(text, ctx))),
3682+ // `@link [href=/about]`: the attribute is the leading argument, so
3683+ // both forms compile the same (`@image [src=a.svg, inline]`). Not
3684+ // for `@source`, whose attribute depends on where it is.
3685+ None if leading.len() == 1 => {
3686+ if let Some(i) = attrs.iter().position(|a| a.html && a.key == leading[0]) {
3687+ argument = Some(attrs.remove(i).value.unwrap_or_default());
1219 // For @slot, the argument is the slot name
3693 // For @slot, the argument is the slot name
1220 let kind = if let ElementKind::Slot(_) = kind {
3694 let kind = if let ElementKind::Slot(_) = kind {
@@ -1223,62 +3697,323 @@ fn parse_single_element(
1226− // Every other element treats its argument as leading text content, as
1227− // in `@el [padding 8] Hello` or `@paragraph Read {@link /more more}`.
1228− let argument = match argument {
1229− Some(_) if !argument_is_special(&kind) && !renders_argument_as_text(&kind) => {
1230− children.insert(0, Node::Text(parse_text_segments(&rest, ctx)));
1236 Ok(Element {
3700 Ok(Element {
1239 argument,
3703 argument,
1240 children,
3704 children,
1241 line_num,
3705 line_num,
1245−/// Elements whose argument is not text content: a URL, a source, an action,
3710+/// Whether `node` or a line inside it calls `@name` outside any `@if`
1246−/// or a slot name.
3711+/// (in a chain, or inline in text).
1247−fn argument_is_special(kind: &ElementKind) -> bool {
3712+fn calls_unguarded(node: &syntax::Node, name: &str) -> bool {
1248− matches!(
3713+ if node.is_directive("if") || node.is_directive("else") {
1249− kind,
3714+ return false;
1250− ElementKind::Link | ElementKind::Image | ElementKind::Script | ElementKind::Slot(_)
3715+ }
1251− ) || kind
3716+ let text_calls = |text: &syntax::Text| {
1252− .spec()
3717+ text.segments
1253− .is_some_and(|spec| matches!(spec.arg, TagArg::Attr(_)))
3718+ .iter()
3719+ .any(|s| matches!(s, Segment::Inline(inline) if inline.head.name == name))
3721+ let here = match &node.kind {
3722+ NodeKind::Element(element) => {
3723+ element.chain.iter().any(|head| head.name == name)
3724+ || element.text.as_ref().is_some_and(text_calls)
3726+ NodeKind::Text(text) => text_calls(text),
3732+ .any(|child| calls_unguarded(child, name))
3735+/// `@td [padding 8] @children`: `@children` and `@slot NAME` mark where a
3736+/// call's content goes only on a line of their own; after an element's
3737+/// attributes, or in a verbatim body, they are text.
3738+fn marker_in_text(node: &syntax::Node) -> Option<Diagnostic> {
3739+ let is_marker = |text: &str| {
3740+ let text = text.trim();
3741+ text == "@children" || text == "@slot" || text.starts_with("@slot ")
3743+ let mut line = node.span.line;
3744+ let mut source = written_line(node);
3745+ let (marker, message) = match &node.kind {
3746+ NodeKind::Element(element) => {
3747+ let text = element.text.as_ref()?;
3748+ if !is_marker(&text.raw) {
3751+ let name = &element.chain.last()?.name;
3752+ let marker = text.raw.trim().to_string();
3753+ let message = format!(
3754+ "`{marker}` after @{name}'s attributes is text: it marks where a call's content \
3755+ goes only on a line of its own, so write it on the next line, indented under \
3760+ NodeKind::Verbatim(verbatim) if verbatim.escaped => {
3761+ let (i, written) = verbatim
3765+ .find(|(_, l)| is_marker(l))?;
3766+ let marker = written.trim().to_string();
3768+ source = written.to_string();
3769+ let message = format!(
3770+ "`{marker}` in a verbatim body is text: the body is written as it is, so it can't \
3771+ hold a call's content (pass the text as a parameter instead)"
3778+ Diagnostic::error(code::MISPLACED_SLOT, line, message)
3784+/// A first word that can't be a leading argument: an inline element
3785+/// (`@link {@b x} y`), or a quote that isn't closed (`@link "a b`).
3786+fn bad_leading_token(
3787+ kind: &ElementKind,
3788+ token: &syntax::Arg,
3790+ ctx: &ParseContext,
3791+) -> Option<Diagnostic> {
3792+ let what = leading_name(kind);
3793+ let name = kind.name();
3794+ let message = if token.raw.starts_with("{@") {
3796+ "@{0} takes its {1} first, before any text: write `@{0} VALUE {2}`, or give it as \
3802+ } else if token.raw.starts_with('"') && syntax::quoted_string(&token.raw).is_none() {
3804+ "@{}'s {} starts with a `\"` that isn't closed: close it (`\"...\"`), or write \
3805+ `\\\"` for a quote in the value",
3811+ let d = Diagnostic::error(code::UNEXPECTED_ARGUMENT, token.span.line, message)
3812+ .subject(token.raw.clone());
3813+ Some(at_attribute(d, Some(token.span.column), ctx))
3816+/// `@link /a > @image logo.png`: a `>` chains only after an element's
3817+/// name or its `[attributes]`, so after a leading argument it is text.
3818+/// Said when what follows names an element or a function.
3819+fn chain_after_argument(
3820+ kind: &ElementKind,
3822+ rest: &syntax::Text,
3823+ ctx: &ParseContext,
3824+) -> Option<Diagnostic> {
3825+ let after = rest.raw.strip_prefix('>')?;
3826+ let name_start = after.trim_start().strip_prefix('@')?;
3827+ if after.len() == after.trim_start().len() {
3830+ let name: String = name_start
3832+ .take_while(|c| c.is_ascii_alphanumeric() || *c == '-')
3834+ if ElementKind::from_name(&name).is_none() && ctx.env.function(&name).is_none() {
3837+ let attr = leading_name(kind);
3838+ let d = Diagnostic::warning(
3839+ code::UNEXPECTED_ARGUMENT,
3842+ "`{}` after @{}'s {} is text, not a chain: `>` chains after an element's name or \
3843+ its [attributes], so write `@{} [{}={}] {}`",
3844+ rest.raw.trim_end(),
3850+ rest.raw.trim_end()
3853+ .subject(rest.raw.trim_end());
3854+ Some(at_attribute(d, Some(rest.span.column), ctx))
3857+/// A leading argument given twice, as the first token and as its
3858+/// attribute: `@link [href=/a] About`.
3860+ kind: &ElementKind,
3861+ token: &syntax::Arg,
3864+ text: &syntax::Text,
3865+ ctx: &ParseContext,
3867+ let name = kind.name();
3868+ let what = leading_name(kind);
3869+ // The value as one token: quoted when it is empty or has a space in it
3870+ let value = if !value.is_empty() && syntax::leading_token_len(value) == value.len() {
3873+ format!("\"{}\"", value.replace('\\', "\\\\").replace('"', "\\\""))
3875+ let written = if takes_no_text(kind) {
3876+ format!("@{} {}", name, value)
3878+ format!("@{} {} {}", name, value, text.raw)
3880+ let d = Diagnostic::error(
3881+ code::DUPLICATE_ATTRIBUTE,
3884+ "@{} takes its first word '{}' as its {}, and it also has {}=: give it once, \
3886+ name, token.raw, what, key, written
3889+ .subject(token.raw.clone());
3890+ at_attribute(d, Some(token.span.column), ctx)
3893+/// The attribute an element's leading argument fills, for messages.
3894+fn leading_name(kind: &ElementKind) -> &'static str {
3896+ TagArg::Source => "srcset in @picture or src elsewhere",
3897+ arg => arg.attribute(false).unwrap_or("argument"),
1256−/// The directive names (without `@`) the parser recognizes, for tools such
3901+/// Whether text after an element's leading argument has nowhere to go:
1257−/// as the language server.
3902+/// an element without content (`@image`, `@source`, ...), or `@optgroup`,
1258−pub fn known_directives() -> &'static [&'static str] {
3903+/// which holds only `@option` lines, so `@optgroup Citrus fruits` would
1259− KNOWN_DIRECTIVES
3904+/// otherwise make `Citrus` the label and drop `fruits`.
3905+fn takes_no_text(kind: &ElementKind) -> bool {
3906+ kind.layout() == Layout::Void || kind.is_tag("optgroup")
1262−const KNOWN_DIRECTIVES: &[&str] = &[
3909+/// Text after the leading argument of an element without content:
1263− "page", "let", "include", "raw", "if", "else", "each", "meta", "head", "style", "markdown",
3910+/// `@image logo.png Our logo`.
1264− "data",
3911+fn after_the_leading_argument(kind: &ElementKind, token: &str, rest: &syntax::Text) -> Diagnostic {
1265−];
3912+ let name = kind.name();
3913+ let attr = leading_name(kind);
3914+ let alt = if matches!(kind, ElementKind::Image) || kind.is_tag("area") {
3915+ " For a text alternative, write `alt=...`."
3919+ let holds = if kind.layout() == Layout::Void {
3920+ "it has no content"
3922+ "it holds only the elements on the lines under it"
3924+ let bare = syntax::quoted_string(token).unwrap_or(token);
3926+ code::UNEXPECTED_ARGUMENT,
3929+ "@{0} takes one word after its attributes, its {1} ('{2}'), and {5}, so '{3}' \
3930+ would go nowhere. A value with a space in it is quoted: `\"{6} {3}\"`.{4}",
3931+ name, attr, token, rest.raw, alt, holds, bare
3934+ .subject(rest.raw.clone())
1267−fn parse_element_kind(s: &str, line_num: usize) -> Result<ElementKind, ParseError> {
3937+/// The element named `name`, or an "unknown element" error that suggests
1268− if let Some(kind) = ElementKind::from_name(s) {
3938+/// the closest element, directive or function.
3939+fn parse_element_kind(
3942+ ctx: &mut ParseContext,
3943+) -> Result<ElementKind, ParseError> {
3944+ if let Some(kind) = ElementKind::from_name(name) {
1269 return Ok(kind);
3945 return Ok(kind);
3947+ // A known name in a place it can't go: say why instead of suggesting
3948+ // the name itself.
3949+ let misplaced = if crate::ast::directive(name).is_some() {
3951+ "unknown element @{}: @{} is a directive, which goes at the start of its own line",
3954+ } else if ctx.env.bundle(name).is_some() {
3956+ "unknown element @{}: '{}' is an attribute bundle, used as `[${}]` \
3957+ (a function is defined with `@let @{}`)",
3958+ name, name, name, name
3960+ } else if ctx.env.value(name).is_some() {
3962+ "unknown element @{}: '{}' is a value, used as `${}` \
3963+ (a function is defined with `@let @{}`)",
3964+ name, name, name, name
3966+ } else if ctx.namespace.contains(name) {
3967+ ctx.used_functions.insert(name.to_string());
3969+ "unknown element @{}: the function @{} isn't visible here. A definition is \
3970+ visible from its line to the end of its block, and a function's body sees what \
3971+ is defined above the function, so define @{} above this line, outside the block \
3975+ } else if matches!(name, "svg" | "math" | "template") {
3977+ "unknown element @{}: htmlang doesn't write <{}>; put its markup in the page with \
3982+ " (or an SVG file with `@image [inline] file.svg`)"
3990+ if let Some(message) = misplaced {
3991+ return Err(Diagnostic::error(code::UNKNOWN_ELEMENT, line_num, message).subject(name));
1271 let all_known: Vec<&str> = ElementKind::all_names()
3993 let all_known: Vec<&str> = ElementKind::all_names()
1272− .chain(KNOWN_DIRECTIVES.iter().copied())
3994+ .chain(DIRECTIVES.iter().map(|d| d.name))
1273 .collect();
3995 .collect();
1274− let message = match suggest_closest(s, &all_known) {
3996+ // An HTML element htmlang writes under its own name (`@a` is `@link`).
1275− Some(closest) => format!("unknown element @{}, did you mean @{}?", s, closest),
3997+ let written_otherwise = crate::ast::HTML_NAMES_WRITTEN_OTHERWISE
1276− None => format!("unknown element @{}", s),
3998+ .iter()
3999+ .find(|(html, _)| *html == name)
4000+ .map(|(_, htmlang)| *htmlang);
4001+ let closest = written_otherwise.or_else(|| suggest_closest(name, &all_known));
4002+ let mut message = match (closest, written_otherwise) {
4003+ (Some(closest), Some(_)) => format!(
4004+ "unknown element @{}, did you mean @{}? (@{} writes <{}>)",
4005+ name, closest, closest, name
4007+ (Some(closest), None) => format!("unknown element @{}, did you mean @{}?", name, closest),
4008+ (None, _) => format!("unknown element @{}", name),
1278− Err(ParseError {
4010+ let function = suggest_fn_name(name, ctx);
1279− line: line_num,
4011+ if let Some(function) = &function {
1280− message,
4012+ message = format!("{}, or did you mean @{}?", message, function);
4014+ Err(Diagnostic::error(code::UNKNOWN_ELEMENT, line_num, message)
4016+ .suggest(closest.map(str::to_string).or(function)))
1284/// Format include/import stack as a readable chain for error messages.
4019/// Format include/import stack as a readable chain for error messages.
@@ -1349,34 +4084,37 @@ fn suggest_closest<'a>(input: &str, candidates: &[&'a str]) -> Option<&'a str> {
1352−/// Suggest the closest user-defined function name for typos.
4087+/// Suggest the closest user-defined function name for typos, from the
4088+/// functions defined so far and those defined anywhere in the file.
1353fn suggest_fn_name(input: &str, ctx: &ParseContext) -> Option<String> {
4089fn suggest_fn_name(input: &str, ctx: &ParseContext) -> Option<String> {
1354 let input_chars: Vec<char> = input.chars().collect();
4090 let input_chars: Vec<char> = input.chars().collect();
1355 let max_allowed = 2usize.min(input_chars.len().saturating_sub(1));
4091 let max_allowed = 2usize.min(input_chars.len().saturating_sub(1));
1356− let mut best: Option<String> = None;
4092+ let mut best: Option<(usize, &String)> = None;
1357− let mut best_dist = usize::MAX;
4093+ let visible: Vec<&String> = ctx.defined_functions.keys().collect();
1358− for name in ctx.functions.keys() {
4094+ for name in visible.into_iter().chain(ctx.namespace.iter()) {
1359 let nlen = name.chars().count();
4095 let nlen = name.chars().count();
1360 if nlen.abs_diff(input_chars.len()) > max_allowed {
4096 if nlen.abs_diff(input_chars.len()) > max_allowed {
1361 continue;
4097 continue;
1363 let name_chars: Vec<char> = name.chars().collect();
4099 let name_chars: Vec<char> = name.chars().collect();
1364 let dist = levenshtein_bounded(&input_chars, &name_chars, max_allowed);
4100 let dist = levenshtein_bounded(&input_chars, &name_chars, max_allowed);
1365− if dist < best_dist && dist <= max_allowed {
4101+ if dist <= max_allowed && best.is_none_or(|b| (dist, name) < b) {
1366− best_dist = dist;
4102+ best = Some((dist, name));
1367− best = Some(name.clone());
1370− best
4105+ best.map(|(_, name)| name.clone())
1373/// Suggest the closest variable name for undefined `$var` references.
4108/// Suggest the closest variable name for undefined `$var` references.
1374−fn suggest_var_name(input: &str, vars: &HashMap<String, String>) -> Option<String> {
4109+fn suggest_var_name(input: &str, vars: &[&str]) -> Option<String> {
1375 let input_chars: Vec<char> = input.chars().collect();
4110 let input_chars: Vec<char> = input.chars().collect();
1376 let max_allowed = 2usize.min(input_chars.len().saturating_sub(1));
4111 let max_allowed = 2usize.min(input_chars.len().saturating_sub(1));
1377 let mut best: Option<String> = None;
4112 let mut best: Option<String> = None;
1378 let mut best_dist = usize::MAX;
4113 let mut best_dist = usize::MAX;
1379− for name in vars.keys().filter(|k| !k.ends_with('#')) {
4114+ let mut vars = vars.to_vec();
4115+ // The same answer every time, whatever the order of the names
4116+ vars.sort_unstable();
1380 let nlen = name.chars().count();
4118 let nlen = name.chars().count();
1381 if nlen.abs_diff(input_chars.len()) > max_allowed {
4119 if nlen.abs_diff(input_chars.len()) > max_allowed {
1382 continue;
4120 continue;
@@ -1385,993 +4123,1950 @@ fn suggest_var_name(input: &str, vars: &HashMap<String, String>) -> Option<Strin
1385 let dist = levenshtein_bounded(&input_chars, &name_chars, max_allowed);
4123 let dist = levenshtein_bounded(&input_chars, &name_chars, max_allowed);
1386 if dist < best_dist && dist <= max_allowed {
4124 if dist < best_dist && dist <= max_allowed {
1387 best_dist = dist;
4125 best_dist = dist;
1388− best = Some(name.clone());
4126+ best = Some(name.to_string());
1394−/// Check for undefined `$var` references and return "did you mean?" diagnostics.
1395−/// `indent` is the line's leading whitespace, which `input` has had trimmed;
1396−/// reported columns and source lines include it.
1397−fn check_undefined_vars(
1399− vars: &HashMap<String, String>,
1402−) -> Vec<Diagnostic> {
1403− let mut warnings = Vec::new();
1404− if !input.contains('$') {
1407− let chars: Vec<char> = input.chars().collect();
1409− while i < chars.len() {
1411− && i + 1 < chars.len()
1412− && (chars[i + 1].is_alphanumeric() || chars[i + 1] == '_' || chars[i + 1] == '-')
1416− let mut end = start;
1417− while end < chars.len()
1418− && (chars[end].is_alphanumeric()
1419− || chars[end] == '-'
1420− || chars[end] == '_'
1421− || chars[end] == '.')
1425− while end > start && chars[end - 1] == '.' {
1428− let name: String = chars[start..end].iter().collect();
1429− if !name.is_empty()
1430− && !vars.contains_key(&name)
1431− && let Some(closest) = suggest_var_name(&name, vars)
1433− warnings.push(Diagnostic {
1435− column: Some(indent + col),
1437− "undefined variable '${}', did you mean '${}'?",
1440− severity: Severity::Warning,
1441− source_line: Some(format!("{}{}", " ".repeat(indent), input)),
1452// ---------------------------------------------------------------------------
4132// ---------------------------------------------------------------------------
1453// Attribute parsing
4133// Attribute parsing
1454// ---------------------------------------------------------------------------
4134// ---------------------------------------------------------------------------
1456−/// Attributes that expect purely numeric values (px-based) or values with CSS units.
4136+/// The quoted strings of a CSS value, without their quotes.
1457−const NUMERIC_ATTRS: &[&str] = &[
4137+fn css_strings(value: &str) -> Vec<&str> {
1458− "spacing",
4138+ let mut strings = Vec::new();
1459− "gap",
4139+ let mut start = None;
1460− "padding",
4140+ let mut escaped = false;
1461− "padding-top",
4141+ for (i, c) in value.char_indices() {
1462− "padding-bottom",
4142+ match (c, start) {
1463− "padding-left",
4143+ _ if escaped => escaped = false,
1464− "padding-right",
4144+ ('\\', Some(_)) => escaped = true,
1465− "min-width",
4145+ ('"', None) => start = Some(i + 1),
1466− "max-width",
4146+ ('"', Some(from)) => {
1467− "min-height",
4147+ strings.push(&value[from..i]);
1468− "max-height",
4148+ start = None;
1480−const CSS_UNIT_SUFFIXES: &[&str] = &[
1481− "px", "%", "rem", "em", "vh", "vw", "vmin", "vmax", "dvh", "svh", "lvh", "ch", "ex", "cm",
1482− "mm", "in", "pt", "pc", "fr",
1485−fn has_css_unit(value: &str) -> bool {
1486− CSS_UNIT_SUFFIXES.iter().any(|u| value.ends_with(u))
1487− || value.starts_with("var(")
1488− || value.starts_with("calc(")
1489− || value.starts_with("clamp(")
1490− || value.starts_with("min(")
1491− || value.starts_with("max(")
1494−/// Attributes that accept numeric OR keyword values.
1495−const NUMERIC_OR_KEYWORD_ATTRS: &[&str] = &["width", "height"];
1496−const SIZE_KEYWORDS: &[&str] = &["fill", "shrink"];
1498−fn validate_attr_value(attr: &Attribute, line_num: usize, ctx: &mut ParseContext) {
1499− let base_key = crate::vocab::base_attribute(attr.key.as_str());
1501− if let Some(val) = &attr.value {
1502− if NUMERIC_ATTRS.contains(&base_key) {
1503− // All space-separated parts must be numeric or have a CSS unit
1504− for part in val.split_whitespace() {
1505− if part.parse::<f64>().is_err() && !has_css_unit(part) {
1506− ctx.diagnostics.push(Diagnostic {
1510− "'{}' expects a numeric value (with optional unit), got '{}'",
1513− severity: Severity::Warning,
1519− } else if NUMERIC_OR_KEYWORD_ATTRS.contains(&base_key) {
4150+ _ => {}
1520− let is_keyword = SIZE_KEYWORDS.contains(&val.as_str());
4151+ }
1521− let is_numeric = val.parse::<f64>().is_ok();
4152+ }
1522− let has_unit = has_css_unit(val);
4153+ strings
1523− if !is_keyword && !is_numeric && !has_unit {
4154+}
1524− ctx.diagnostics.push(Diagnostic {
4155+
1525− line: line_num,
4156+/// An `if(...)` in a CSS value that isn't CSS's if(): CSS writes each
1526− column: None,
4157+/// branch `CONDITION: VALUE`, so an if() without a `:` is something else.
1527− message: format!(
4158+/// Quoted CSS strings are text, not calls.
1528− "'{}' expects a number or one of [{}], got '{}'",
4159+fn not_css_if(value: &str) -> Option<&str> {
1529− attr.key,
4160+ let mut quote = None;
1530− SIZE_KEYWORDS.join(", "),
4161+ let mut prev = None;
1531− val
4162+ let mut chars = value.char_indices();
1532− ),
4163+ while let Some((at, c)) = chars.next() {
1533− severity: Severity::Warning,
4164+ match quote {
1534− source_line: None,
4165+ Some(_) if c == '\\' => {
1535− });
4166+ chars.next();
1537− } else if base_key == "opacity" {
4168+ Some(q) if c == q => quote = None,
1538− if let Ok(v) = val.parse::<f64>() {
4169+ Some(_) => {}
1539− if !(0.0..=1.0).contains(&v) {
4170+ None if matches!(c, '"' | '\'') => quote = Some(c),
1540− ctx.diagnostics.push(Diagnostic {
4171+ None => {
1541− line: line_num,
4172+ let word_before =
1542− column: None,
4173+ prev.is_some_and(|p: char| p.is_alphanumeric() || matches!(p, '-' | '_'));
1543− message: format!("'opacity' should be between 0 and 1, got '{}'", val),
4174+ if !word_before && value[at..].starts_with("if(") {
1544− severity: Severity::Warning,
4175+ let mut depth = 0;
1545− source_line: None,
4176+ let close = value[at + 2..].char_indices().find_map(|(i, c)| {
4182+ (depth == 0).then_some(at + 2 + i)
4184+ let end = close.map_or(value.len(), |c| c + 1);
4185+ if !value[at + 3..end].contains(':') {
4186+ return Some(&value[at..end]);
1549− ctx.diagnostics.push(Diagnostic {
1552− message: format!("'opacity' expects a numeric value, got '{}'", val),
1553− severity: Severity::Warning,
1557− } else if base_key == "z-index" {
4190+ }
1558− if val.parse::<i32>().is_err() {
4191+ prev = Some(c);
1559− ctx.diagnostics.push(Diagnostic {
4192+ }
1560− line: line_num,
4193+ None
1561− column: None,
4194+}
1562− message: format!("'z-index' expects an integer, got '{}'", val),
4195+
1563− severity: Severity::Warning,
4196+/// Why a CSS value can't be written into a rule as it is, whatever it
1564− source_line: None,
4197+/// means: a `;` (outside parentheses, where CSS's own `if()` uses it), a
1565− });
4198+/// `{` or a `}` would end the declaration or the rule, and an unclosed
4199+/// quote or parenthesis would run on into the rules after it. Quoted
4200+/// strings are text, and a backslash escapes the character after it, as
4201+/// in CSS. A `</style` anywhere, even in a string, would end the page's
4202+/// `<style>` element and start HTML.
4203+fn css_breakout(value: &str) -> Option<&'static str> {
4204+ if value.to_ascii_lowercase().contains("</style") {
4205+ return Some("a `</style`, which would end the page's style element");
4207+ let mut quote = None;
4208+ let mut depth = 0usize;
4209+ let mut chars = value.chars();
4210+ while let Some(c) = chars.next() {
1567− } else if base_key == "display" {
4215+ (Some(q), c) if c == q => quote = None,
1568− const DISPLAY_VALUES: &[&str] = &[
4216+ (Some(_), _) => {}
1569− "none",
4217+ (None, '"' | '\'') => quote = Some(c),
1570− "block",
4218+ (None, '(') => depth += 1,
1571− "inline",
4219+ (None, ')') if depth == 0 => return Some("a `)` that closes nothing"),
1572− "inline-block",
4220+ (None, ')') => depth -= 1,
1573− "flex",
4221+ (None, ';') if depth == 0 => return Some("a `;`, which would end the declaration"),
1574− "inline-flex",
4222+ (None, '{' | '}') => return Some("a `{` or `}`, which would end the CSS rule"),
1575− "grid",
4223+ _ => {}
1576− "inline-grid",
4224+ }
1578− "table-row",
4226+ match (quote, depth) {
1579− "table-cell",
4227+ (Some('"'), _) => Some("a `\"` that isn't closed"),
1580− "contents",
4228+ (Some(_), _) => Some("a `'` that isn't closed"),
1581− "flow-root",
4229+ (None, 0) => None,
1582− "list-item",
4230+ (None, _) => Some("a `(` that isn't closed"),
1584− if !DISPLAY_VALUES.contains(&val.as_str()) && !val.starts_with("var(") {
4232+}
1585− let suggestion = suggest_closest(val, DISPLAY_VALUES);
4233+
1586− let msg = match suggestion {
4234+/// The hex colors of a CSS value that don't have 3, 4, 6 or 8 hex
1587− Some(s) => format!("unknown display value '{}', did you mean '{}'?", val, s),
4235+/// digits. A `#` word in a CSS value is a color, except inside `url(...)`
1588− None => format!("unknown display value '{}'", val),
4236+/// and quoted strings.
1589− };
4237+fn bad_hex_colors(value: &str) -> Vec<&str> {
1590− ctx.diagnostics.push(Diagnostic {
4238+ let mut bad = Vec::new();
1591− line: line_num,
4239+ let mut quote = None;
1592− column: None,
4240+ let mut in_url = 0usize;
1593− message: msg,
4241+ let mut depth = 0usize;
1594− severity: Severity::Warning,
4242+ let mut chars = value.char_indices().peekable();
1595− source_line: None,
4243+ while let Some((at, c)) = chars.next() {
1596− });
4244+ match (quote, c) {
1598− } else if base_key == "position" {
4248+ (Some(q), c) if c == q => quote = None,
1599− const POSITION_VALUES: &[&str] = &["static", "relative", "absolute", "fixed", "sticky"];
4249+ (Some(_), _) => {}
1600− if !POSITION_VALUES.contains(&val.as_str()) && !val.starts_with("var(") {
4250+ (None, '"' | '\'') => quote = Some(c),
1601− let suggestion = suggest_closest(val, POSITION_VALUES);
4251+ (None, '(') => {
1602− let msg = match suggestion {
4252+ depth += 1;
1603− Some(s) => format!("unknown position value '{}', did you mean '{}'?", val, s),
4253+ if value[..at].ends_with("url") && in_url == 0 {
1604− None => format!("unknown position value '{}'", val),
4254+ in_url = depth;
1606− ctx.diagnostics.push(Diagnostic {
1610− severity: Severity::Warning,
1614− } else if base_key == "overflow" || base_key == "overflow-x" || base_key == "overflow-y" {
4257+ (None, ')') => {
1615− const OVERFLOW_VALUES: &[&str] = &["visible", "hidden", "scroll", "auto", "clip"];
4258+ if in_url == depth {
1616− if !OVERFLOW_VALUES.contains(&val.as_str()) && !val.starts_with("var(") {
4259+ in_url = 0;
1617− let suggestion = suggest_closest(val, OVERFLOW_VALUES);
4260+ }
1618− let msg = match suggestion {
4261+ depth = depth.saturating_sub(1);
1619− Some(s) => format!("unknown overflow value '{}', did you mean '{}'?", val, s),
1620− None => format!("unknown overflow value '{}'", val),
1622− ctx.diagnostics.push(Diagnostic {
1626− severity: Severity::Warning,
1630− } else if base_key == "text-align" {
4263+ (None, '#') if in_url == 0 => {
1631− const TEXT_ALIGN_VALUES: &[&str] =
4264+ let end = value[at + 1..]
1632− &["left", "right", "center", "justify", "start", "end"];
4265+ .find(|c: char| !(c.is_alphanumeric() || c == '-' || c == '_'))
1633− if !TEXT_ALIGN_VALUES.contains(&val.as_str()) && !val.starts_with("var(") {
4266+ .map_or(value.len(), |n| at + 1 + n);
1634− let suggestion = suggest_closest(val, TEXT_ALIGN_VALUES);
4267+ let hex = &value[at + 1..end];
1635− let msg = match suggestion {
4268+ if !(matches!(hex.len(), 3 | 4 | 6 | 8)
1636− Some(s) => format!("unknown text-align value '{}', did you mean '{}'?", val, s),
4269+ && hex.chars().all(|c| c.is_ascii_hexdigit()))
1637− None => format!("unknown text-align value '{}'", val),
4270+ {
1638− };
4271+ bad.push(&value[at..end]);
1639− ctx.diagnostics.push(Diagnostic {
4272+ }
1643− severity: Severity::Warning,
1647− } else if base_key == "cursor" {
4274+ _ => {}
1648− const CURSOR_VALUES: &[&str] = &[
4275+ }
1650− "default",
4277+ bad
1653− "wait",
4280+/// A diagnostic about an attribute, with its column and source line when
1654− "text",
4281+/// it is on the line being evaluated.
1655− "move",
4282+fn at_attribute(diagnostic: Diagnostic, column: Option<usize>, ctx: &ParseContext) -> Diagnostic {
1656− "not-allowed",
4283+ match (&ctx.current_source, column) {
1657− "crosshair",
4284+ ((current, Some(text)), Some(column)) if *current == diagnostic.line => {
1658− "grab",
4285+ diagnostic.column(column).source(text.clone())
1660− "help",
4287+ _ => diagnostic,
1662− "col-resize",
4289+}
1664− "n-resize",
4291+/// Check a style's value. Values go to the CSS as written, so only what
1665− "s-resize",
4292+/// can't be wrong in any CSS is checked: a value that would break out of
1666− "e-resize",
4293+/// its rule is an error (and it is left out); a hex color without 3, 4, 6
1667− "w-resize",
4294+/// or 8 digits, an `if()` that isn't CSS's and a quoted font stack are
1668− "zoom-in",
4295+/// warnings. Returns whether the value can be written.
1669− "zoom-out",
4296+fn check_css_value(
1670− "context-menu",
4297+ attr: &Attribute,
1671− "cell",
4298+ base: &str,
1672− "copy",
4299+ line: usize,
1673− "alias",
4300+ column: Option<usize>,
1674− "no-drop",
4301+ ctx: &mut ParseContext,
1676− if !CURSOR_VALUES.contains(&val.as_str())
4303+ let Some(value) = &attr.value else {
1677− && !val.starts_with("url(")
4304+ return true;
1678− && !val.starts_with("var(")
4305+ };
4306+ if let Some(reason) = css_breakout(value) {
4307+ let diagnostic = Diagnostic::error(
4308+ code::INVALID_VALUE,
4311+ "the value of '{}' has {}: `{}` can't be written into the page's CSS",
4312+ attr.key, reason, value
4315+ .subject(value.as_str());
4316+ ctx.diagnostics.push(at_attribute(diagnostic, column, ctx));
4319+ if crate::vocab::is_custom_property(base) {
4323+ let warn = |ctx: &mut ParseContext, diagnostic: Diagnostic| {
4324+ let diagnostic = at_attribute(diagnostic, column, ctx);
4325+ ctx.diagnostics.push(diagnostic);
4327+ // In CSS, a quoted font-family is one family, commas and all
4328+ if base == "font-family"
4329+ && let Some(family) = css_strings(value).into_iter().find(|s| s.contains(','))
4334+ .collect::<Vec<_>>()
4338+ Diagnostic::warning(
4339+ code::INVALID_VALUE,
4342+ "font-family \"{}\" is one family, whose name has a comma in it: \
4343+ for a font stack, write `font-family {}`",
4347+ .subject(format!("\"{}\"", family))
4348+ .suggest(Some(stack)),
4351+ if let Some(call) = not_css_if(value) {
4354+ Diagnostic::warning(
4355+ code::INVALID_VALUE,
4358+ "'{}' is not CSS's if(), whose branches are written \
4359+ `if(CONDITION: VALUE; else: VALUE)`",
4366+ for color in bad_hex_colors(value) {
4369+ Diagnostic::warning(
4370+ code::INVALID_COLOR,
4373+ "invalid hex color '{}': a hex color has 3, 4, 6 or 8 hex digits",
4383+/// An unknown prefix: the message, the text it is about, and what to write
4384+/// instead, when something is close enough.
4385+struct PrefixProblem {
4388+ suggestion: Option<String>,
4391+/// What is wrong with the prefix `rest` starts with, when the known
4392+/// prefixes are already split off it and what is left still starts with
4393+/// one: a word and a `:` (`hovr:`), or a word and a parenthesised argument
4394+/// and a `:` (`nth-chld(2):`). Selector prefixes are CSS's pseudo-classes
4395+/// and pseudo-elements under their CSS names, so an unknown one gets the
4396+/// closest name as a suggestion. Only names with the same first letter are
4397+/// suggested: `odd:` is two edits from `md:`, which it doesn't mean.
4398+fn unknown_prefix(rest: &str) -> Option<PrefixProblem> {
4399+ use crate::vocab::{self, Pseudo};
4400+ let name_len = rest.find(|c: char| !(c.is_ascii_alphanumeric() || c == '-'))?;
4401+ let name = &rest[..name_len];
4402+ if name.is_empty() {
4405+ if rest[name_len..].starts_with('(') {
4406+ // `name(...):`: a pseudo-class with an argument
4407+ let close = vocab::closing_paren(rest, name_len)?;
4408+ if !rest[close + 1..].starts_with(':') {
4411+ let written = &rest[..close + 2];
4412+ if matches!(vocab::pseudo(name), Some(Pseudo::Class | Pseudo::Element)) {
4413+ let bare = format!("{}:", name);
4414+ return Some(PrefixProblem {
4416+ "'{}': `{}` takes no argument: write `{}`",
4418+ vocab::pseudo_selector(&bare).unwrap_or_default(),
4421+ subject: written.to_string(),
4422+ suggestion: Some(bare),
4425+ let functional: Vec<&str> = vocab::functional_pseudos()
4427+ .filter(|p| p.chars().next() == name.chars().next())
4429+ let suggestion = suggest_closest(name, &functional)
4430+ .filter(|&closest| closest != name)
4431+ .map(|closest| format!("{}(", closest));
4432+ let written = format!("{}(", name);
4433+ let message = match &suggestion {
4434+ Some(closest) => format!("unknown prefix '{}', did you mean '{}'?", written, closest),
4435+ None => format!("unknown prefix '{}'", written),
4437+ return Some(PrefixProblem {
4443+ if !rest[name_len..].starts_with(':') {
4446+ let written = &rest[..name_len + 1];
4447+ // `has:`: its argument is missing
4448+ if vocab::pseudo(name) == Some(Pseudo::Function) {
4449+ return Some(PrefixProblem {
4451+ "'{}': `:{}()` takes an argument, in parentheses, as in CSS: `{}(...):`",
4452+ written, name, name
4454+ subject: written.to_string(),
4458+ let prefixes = vocab::all_prefixes();
4459+ let candidates: Vec<&str> = prefixes
4461+ .map(String::as_str)
4462+ .filter(|p| p.chars().next() == written.chars().next())
4464+ // The closest name that starts with the same letter (`hvoer:` →
4465+ // `hover:`), else the first that starts with the word written and a `-`
4466+ // (`first:` → `first-child:`)
4467+ let suggestion = suggest_closest(written, &candidates)
4469+ let longer = format!("{}-", name);
4470+ candidates.iter().copied().find(|p| p.starts_with(&longer))
4472+ .filter(|&closest| closest != written)
4473+ .map(str::to_string);
4474+ let message = match &suggestion {
4475+ Some(closest) => format!("unknown prefix '{}', did you mean '{}'?", written, closest),
4476+ None => format!("unknown prefix '{}'", written),
4478+ Some(PrefixProblem {
4480+ subject: written.to_string(),
4485+/// Check an attribute's element prefix (`@td:padding 8`), when it has one:
4486+/// it names a built-in element that has an HTML tag of its own (not a
4487+/// function, and not `@el`, whose `<div>` other elements write too), there
4488+/// is one, not with `children:`, and what it styles is a CSS property, not
4489+/// one of htmlang's words, which compile against each element's layout and
4490+/// its parent's. Returns false, after reporting, when the attribute can't
4492+fn check_element_prefixes(
4497+ column: Option<usize>,
4498+ ctx: &mut ParseContext,
4500+ use crate::ast::ElementKind;
4502+ let elements: Vec<&str> = prefixes
4505+ .filter(|p| vocab::element_prefix(p).is_some())
4507+ let Some(&prefix) = elements.first() else {
4510+ let fail = |ctx: &mut ParseContext,
4511+ code: &'static str,
4514+ suggestion: Option<String>| {
4515+ let diagnostic = Diagnostic::error(code, line, message)
4517+ .suggest(suggestion);
4518+ let diagnostic = at_attribute(diagnostic, column, ctx);
4519+ ctx.diagnostics.push(diagnostic);
4522+ let name = vocab::element_prefix(prefix).unwrap_or_default();
4523+ if is_function(name, ctx) {
4526+ code::INVALID_PREFIX,
4528+ "'{}': @{} is a function, and `{}` would pick elements out by their HTML tag, \
4529+ which a function doesn't have: style what @{} writes in its body, or pass it \
4531+ attr.key, name, prefix, name
4537+ match ElementKind::from_name(name) {
4539+ let own: Vec<&str> = ElementKind::all_names()
4540+ .filter(|n| ElementKind::from_name(n).is_some_and(|k| k.own_tag().is_some()))
4542+ // An HTML name htmlang writes under another (`@a:` is `@link:`)
4543+ let (written_otherwise, shared) = match crate::ast::HTML_NAMES_WRITTEN_OTHERWISE
4545+ .find(|(html, _)| *html == name)
1680− let suggestion = suggest_closest(val, CURSOR_VALUES);
4547+ Some((_, htmlang)) if own.contains(htmlang) => (Some(*htmlang), false),
1681− let msg = match suggestion {
4548+ Some(_) => (None, true),
1682− Some(s) => format!("unknown cursor value '{}', did you mean '{}'?", val, s),
4549+ None => (None, false),
1683− None => format!("unknown cursor value '{}'", val),
4550+ };
1684− };
4551+ // `@each:`, `@markdown:`: a directive, which is no element
1685− ctx.diagnostics.push(Diagnostic {
4552+ if crate::ast::directive(name).is_some() {
1686− line: line_num,
4553+ return fail(
1687− column: None,
4554+ ctx,
1688− message: msg,
4555+ code::UNKNOWN_PREFIX,
1689− severity: Severity::Warning,
4556+ format!(
1690− source_line: None,
4557+ "unknown element @{} in '{}': @{} is a directive, and an element \
1691− });
4558+ prefix names an element with an HTML tag of its own, such as `@td:`",
1693− } else if base_key == "font-weight" {
4565+ // `@div:`, `@span:`: several elements write it
1694− const WEIGHT_VALUES: &[&str] = &[
4566+ if shared {
1695− "normal", "bold", "bolder", "lighter", "100", "200", "300", "400", "500", "600",
4567+ return fail(
1696− "700", "800", "900",
4568+ ctx,
1697− ];
4569+ code::UNKNOWN_PREFIX,
1698− if !WEIGHT_VALUES.contains(&val.as_str()) && !val.starts_with("var(") {
4570+ format!(
1699− ctx.diagnostics.push(Diagnostic {
4571+ "unknown element @{} in '{}': htmlang writes <{}> for several \
1700− line: line_num,
4572+ elements, so no element prefix picks it out",
1701− column: None,
4573+ name, prefix, name
1703− "'font-weight' expects a weight keyword or number 100-900, got '{}'",
1706− severity: Severity::Warning,
4575+ prefix,
1707− source_line: None,
4576+ None,
1710− } else if base_key == "color" || base_key == "background" {
4579+ // A name with the same first letter first (`@tdd:` is `@td:`)
1711− // Validate named CSS colors (only if not hex, rgb, hsl, var, etc.)
4580+ let same_letter: Vec<&str> = own
1712− if !val.starts_with('#')
4581+ .iter()
1713− && !val.starts_with("rgb")
4582+ .copied()
1714− && !val.starts_with("hsl")
4583+ .filter(|n| n.chars().next() == name.chars().next())
1715− && !val.starts_with("var(")
4584+ .collect();
1716− && !val.starts_with("linear-gradient")
4585+ let closest = written_otherwise
1717− && !val.starts_with("radial-gradient")
4586+ .or_else(|| suggest_closest(name, &same_letter))
1718− && !val.starts_with("conic-gradient")
4587+ .or_else(|| suggest_closest(name, &own));
1719− && !val.starts_with("oklch")
4588+ let message = match (closest, written_otherwise) {
1720− && !val.starts_with("oklab")
4589+ (Some(closest), Some(_)) => format!(
1721− && !val.starts_with("color(")
4590+ "unknown element @{} in '{}', did you mean '@{}:'? (@{} writes <{}>)",
1722− && !val.starts_with("light-dark(")
4591+ name, prefix, closest, closest, name
1723− && !val.contains("url(")
4592+ ),
1724− && !val.contains(' ')
4593+ (Some(closest), None) => format!(
1725− // skip shorthand multi-value
4594+ "unknown element @{} in '{}', did you mean '@{}:'?",
1726− {
4595+ name, prefix, closest
1727− const NAMED_COLORS: &[&str] = &[
4596+ ),
1728− "transparent",
4597+ (None, _) => format!("unknown element @{} in '{}'", name, prefix),
1729− "currentcolor",
4598+ };
1730− "inherit",
4599+ let suggestion = closest.map(|c| format!("@{}:", c));
1731− "initial",
4600+ fail(ctx, code::UNKNOWN_PREFIX, message, prefix, suggestion)
1733− "black",
4602+ Some(kind) if kind.own_tag().is_none() => {
1734− "white",
4603+ let reason = match kind.tag() {
1735− "red",
4604+ None => format!(
1736− "green",
4605+ "@{} writes no element of its own, so there is nothing for `{}` to style",
1737− "blue",
4606+ name, prefix
1739− "orange",
4608+ Some(_) if kind.is_verbatim() => {
1740− "purple",
4609+ format!("@{} isn't shown, so there is nothing to style", name)
1742− "brown",
4611+ Some("span") => format!(
1743− "gray",
4612+ "@{} writes a <span>, as every line of text in a row or column does, so \
1744− "grey",
4613+ `{}` can't pick it out",
1745− "cyan",
4614+ name, prefix
1747− "lime",
4616+ Some(tag) => {
1748− "olive",
4617+ let others: Vec<String> = ElementKind::all_names()
1749− "navy",
4618+ .filter(|n| {
1750− "teal",
4619+ *n != name
1751− "aqua",
4620+ && ElementKind::from_name(n).and_then(|k| k.tag()) == Some(tag)
1753− "maroon",
4622+ .map(|n| format!("@{}", n))
1754− "silver",
4623+ .collect();
1755− "coral",
4624+ let others = match others.split_last() {
1756− "salmon",
4625+ Some((last, [])) => last.clone(),
1757− "tomato",
4626+ Some((last, rest)) => format!("{} and {}", rest.join(", "), last),
1758− "crimson",
4627+ None => String::new(),
1796− if !NAMED_COLORS.contains(&val.to_lowercase().as_str()) {
1797− let lower = val.to_lowercase();
1798− let suggestion = suggest_closest(&lower, NAMED_COLORS);
1799− let msg = match suggestion {
1800− Some(s) => format!("unknown color '{}', did you mean '{}'?", val, s),
1801− None => format!("unknown color '{}'", val),
1803− ctx.diagnostics.push(Diagnostic {
4629+ format!(
1804− line: line_num,
4630+ "@{} writes a <{}>, as {} do, so `{}` can't pick it out",
1805− column: None,
4631+ name, tag, others, prefix
1806− message: msg,
4632+ )
1807− severity: Severity::Warning,
4637+ code::INVALID_PREFIX,
4639+ "'{}': {}. Give those elements their styles themselves, or a bundle \
4640+ (`@let name [...]`, used as `[$name]`)",
4647+ Some(_) if elements.len() > 1 => fail(
4649+ code::INVALID_PREFIX,
4651+ "'{}': a style takes one element prefix, which styles every such element \
4652+ inside this one, at any depth",
4658+ Some(_) if prefixes.contains(&vocab::CHILDREN) => fail(
4660+ code::INVALID_PREFIX,
4662+ "'{}': `children:` and `{}` each say which elements the style is for: write \
4669+ Some(_) if vocab::is_htmlang_word(base, attr.value.as_deref()) => {
4670+ let value = attr.value.as_deref().map(str::trim);
4671+ let css = match (base, value) {
4672+ ("spacing", _) => " (`gap`)",
4673+ ("wrap", _) => " (`flex-wrap wrap`)",
4674+ ("grid-cols", _) => " (`grid-template-columns`)",
4675+ ("grid-rows", _) => " (`grid-template-rows`)",
4676+ ("col-span", _) => " (`grid-column span N`)",
4677+ ("row-span", _) => " (`grid-row span N`)",
4678+ ("width", Some("fill")) => " (`flex 1` in a row, `width 100%` otherwise)",
4679+ ("height", Some("fill")) => " (`flex 1` in a column, `height 100%` otherwise)",
4680+ ("width", _) => " (`flex-shrink 0` in a row, `width fit-content` otherwise)",
4681+ ("height", _) => " (`flex-shrink 0` in a column, `height fit-content` otherwise)",
4682+ ("center-x", _) => " (`margin-inline auto`)",
4683+ ("center-y", _) => " (`margin-block auto`)",
4686+ let word = match value {
4687+ Some(v) if matches!(base, "width" | "height") => format!("{} {}", base, v),
4688+ _ => base.to_string(),
4692+ code::INVALID_PREFIX,
4694+ "'{}': `{}` is one of htmlang's layout words, which compile against each \
4695+ element's layout and its parent's, and `{}` styles elements whose \
4696+ parents it doesn't know: write `{}` on the elements themselves, or the \
4698+ attr.key, word, prefix, word, css
4708+/// Check an attribute's prefixes: each is known, their selector prefixes
4709+/// read left to right with a pseudo-element (`before:`) last, the argument
4710+/// of `has(...)` or `nth-child(...)` can be written into the CSS, and a word that
4711+/// places an element in its parent (`width fill`, `center-x`, `align-*`)
4712+/// isn't under `children:`, whose styles go on the children. Media,
4713+/// container and width prefixes go anywhere. Returns false, after
4714+/// reporting, when the attribute can't be written.
4718+ column: Option<usize>,
4719+ ctx: &mut ParseContext,
4722+ let (prefixes, base) = vocab::split_prefixes(&attr.key);
4724+ |ctx: &mut ParseContext, message: String, subject: &str, suggestion: Option<String>| {
4725+ let diagnostic = Diagnostic::error(code::INVALID_PREFIX, line, message)
4727+ .suggest(suggestion);
4728+ let diagnostic = at_attribute(diagnostic, column, ctx);
4729+ ctx.diagnostics.push(diagnostic);
4733+ if let Some(problem) = unknown_prefix(base) {
4734+ let diagnostic = Diagnostic::error(code::UNKNOWN_PREFIX, line, problem.message)
4735+ .subject(problem.subject)
4736+ .suggest(problem.suggestion);
4737+ let diagnostic = at_attribute(diagnostic, column, ctx);
4738+ ctx.diagnostics.push(diagnostic);
4741+ if !check_element_prefixes(attr, &prefixes, base, line, column, ctx) {
4744+ // The argument of `has(...)` or `nth-child(...)` goes into the CSS as
4746+ for prefix in &prefixes {
4747+ if let Some(reason) = css_breakout(prefix.trim_end_matches(':')) {
4751+ "the prefix '{}' has {}: it can't be written into the page's CSS",
4759+ // `nth-child():` or `has( ):`: CSS has no pseudo-class with an empty
4761+ let empty_argument = |prefix: &str| {
4763+ .strip_suffix("):")
4764+ .and_then(|p| p.split_once('('))
4765+ .is_some_and(|(_, argument)| argument.trim().is_empty())
4767+ if let Some(empty) = prefixes.iter().find(|p| empty_argument(p)) {
4771+ "'{}': `:{}()` takes an argument between its parentheses, as in CSS",
4773+ vocab::pseudo_name(empty)
4779+ // A pseudo-element is the last selector prefix: CSS has no
4780+ // `::before:hover`
4781+ let selectors: Vec<&str> = prefixes
4784+ .filter(|p| vocab::at_rule_rank(p).is_none())
4786+ // Only one: an element has one `::before`, which has no `::after`
4787+ let elements: Vec<&str> = selectors
4790+ .filter(|p| vocab::is_pseudo_element(p))
4792+ if elements.len() > 1 {
4796+ "'{}': `{}` and `{}` each select a pseudo-element, and a style applies to one \
4798+ attr.key, elements[0], elements[1]
4804+ if let Some(at) = selectors.iter().position(|p| vocab::is_pseudo_element(p))
4805+ && at + 1 < selectors.len()
4807+ let element = selectors[at];
4808+ // The same prefixes, with the pseudo-element moved after the other
4809+ // selector prefixes
4810+ let mut order: Vec<&str> = prefixes.iter().copied().filter(|p| *p != element).collect();
4811+ let last_selector = order
4813+ .rposition(|p| vocab::at_rule_rank(p).is_none())
4814+ .map_or(order.len(), |i| i + 1);
4815+ order.insert(last_selector, element);
4816+ let fixed = format!("{}{}", order.concat(), base);
4820+ "'{}': `{}` selects a pseudo-element, which comes after the other selector \
4821+ prefixes, as in CSS: write `{}`",
4822+ attr.key, element, fixed
4828+ // Under `children:` the styles go on the children, whose parent is this
4829+ // element: a word that places an element in its parent can't say where
4830+ if prefixes.contains(&"children:") && vocab::places_in_parent(base, attr.value.as_deref()) {
4831+ // The CSS of `fill` and `shrink` depends on the direction: along
4832+ // it, they are flex properties
4833+ let (word, css) = match (base, attr.value.as_deref().map(str::trim)) {
4834+ ("width", Some("fill")) => (
4836+ " (`children:flex 1` in a row, `children:width 100%` otherwise)",
4838+ ("height", Some("fill")) => (
4840+ " (`children:flex 1` in a column, `children:height 100%` otherwise)",
4842+ ("width", Some(_)) => (
4844+ " (`children:flex-shrink 0` in a row, `children:width fit-content` otherwise)",
4846+ ("height", Some(_)) => (
4848+ " (`children:flex-shrink 0` in a column, `children:height fit-content` \
4856+ "'{}{}': `{}` places an element in its parent, and under `children:` that \
4857+ parent is this element: write `{}` on the children themselves, or the CSS \
4862+ .map_or(String::new(), |v| format!(" {}", v.trim())),
4874+/// Check an attribute written as a style or a flag (not `key=value`): its
4875+/// prefix, its name, and, for a style, its value. A name htmlang doesn't
4876+/// know but CSS could have (`corner-shape`) is passed to the CSS as written,
4877+/// with a warning; custom properties (`--brand`) and vendor-prefixed ones
4878+/// (`-webkit-...`) without one. Anything that can't be written into the
4879+/// page is an error; returns false then, and the attribute is left out.
4883+ column: Option<usize>,
4884+ after_another: bool,
4885+ ctx: &mut ParseContext,
4888+ let (prefixes, base) = vocab::split_prefixes(&attr.key);
4889+ let fail = |ctx: &mut ParseContext, code: &'static str, message: String, subject: &str| {
4890+ let diagnostic = Diagnostic::error(code, line, message).subject(subject);
4891+ let diagnostic = at_attribute(diagnostic, column, ctx);
4892+ ctx.diagnostics.push(diagnostic);
4896+ if !check_prefixes(attr, line, column, ctx) {
4899+ let prefixed = !prefixes.is_empty();
4900+ // `md:id=x`: `=` makes an HTML attribute, which has no states
4901+ if prefixed && let Some((name, _)) = base.split_once('=') {
4904+ code::INVALID_PREFIX,
4906+ "'{}': a prefix applies to a style, and `{}=` is an HTML attribute",
4912+ let is_html_name = |name: &str| {
4913+ vocab::HTML_ATTRIBUTES.contains(&name)
4914+ || name.starts_with("aria-")
4915+ || name.starts_with("data-")
4918+ let Some(value) = &attr.value else {
4919+ // `inline` puts a file into the page as it compiles, which no
4920+ // state or media condition can undo
4921+ if base == "inline" && prefixed {
4924+ code::INVALID_PREFIX,
4926+ "'{}': `inline` puts the image's file into the page, which can't depend \
4933+ if vocab::HTMLANG_FLAGS.contains(&base) {
4936+ if vocab::BOOLEAN_HTML_ATTRS.contains(&base) {
4942+ code::INVALID_PREFIX,
4944+ "'{}': a prefix applies to a style, and '{}' is an HTML attribute",
4950+ if vocab::is_style_attribute(base)
4951+ || vocab::is_custom_property(base)
4952+ || vocab::is_vendor_property(base)
4956+ code::MISSING_VALUE,
4957+ format!("'{}' needs a value: `{} VALUE`", attr.key, attr.key),
4961+ if is_html_name(base) && !prefixed {
4964+ code::HTML_ATTRIBUTE_FORM,
4966+ "'{}' is an HTML attribute that isn't a flag: write `{}=VALUE`",
4972+ return unknown_attribute(attr, base, line, column, after_another, true, ctx);
4975+ if vocab::HTMLANG_FLAGS.contains(&base) {
4978+ code::INVALID_VALUE,
4980+ "'{}' is a flag and takes no value: write `{}` alone",
4986+ if vocab::is_style_attribute(base)
4987+ || vocab::is_custom_property(base)
4988+ || vocab::is_vendor_property(base)
4990+ return check_css_value(attr, base, line, column, ctx);
4992+ if is_html_name(base) && !prefixed {
4993+ let diagnostic = Diagnostic::error(
4994+ code::HTML_ATTRIBUTE_FORM,
4997+ "'{}' is an HTML attribute: write `{}={}`",
4998+ attr.key, attr.key, value
5001+ .subject(attr.key.as_str());
5002+ let diagnostic = at_attribute(diagnostic, column, ctx);
5003+ ctx.diagnostics.push(diagnostic);
5006+ let passes = vocab::is_property_name(base);
5007+ unknown_attribute(attr, base, line, column, after_another, !passes, ctx)
5008+ && check_css_value(attr, base, line, column, ctx)
1816−fn parse_attr_brackets(
5011+/// Whether an attribute of a bundle could pass a parameter to a function
1817− input: &str,
5012+/// it is spliced into (`@let t [title Hello]`): a name without a prefix
1818− line_num: usize,
5013+/// that isn't a style or a flag. Such a name is checked where the bundle is
5015+fn could_be_parameter(attr: &Attribute) -> bool {
5017+ let key = attr.key.as_str();
5018+ let flag = attr.value.is_none()
5019+ && (vocab::HTMLANG_FLAGS.contains(&key) || vocab::BOOLEAN_HTML_ATTRS.contains(&key));
5022+ && !vocab::is_style_attribute(key)
5023+ && key.starts_with(|c: char| c.is_alphabetic())
5026+ .all(|c| c.is_alphanumeric() || matches!(c, '-' | '_'))
5029+/// At a call, a name close to one of the function's parameters is a
5030+/// misspelled parameter, not an attribute for its root: report it, and
5031+/// return true (it is left out).
5032+fn misspelled_parameter(
5034+ text_keys: &[String],
5036+ column: Option<usize>,
5037+ ctx: &mut ParseContext,
5039+ if text_keys.is_empty() || !could_be_parameter(attr) {
5042+ let params: Vec<&str> = text_keys.iter().map(String::as_str).collect();
5043+ let Some(closest) = suggest_closest(&attr.key, ¶ms) else {
5046+ let what = if ctx.in_page {
5051+ let diagnostic = Diagnostic::error(
5052+ code::UNKNOWN_ATTRIBUTE,
5055+ "unknown {} '{}', did you mean '{}'?",
5056+ what, attr.key, closest
5059+ .subject(attr.key.as_str())
5060+ .suggest(Some(closest));
5061+ let diagnostic = at_attribute(diagnostic, column, ctx);
5062+ ctx.diagnostics.push(diagnostic);
5066+/// An attribute name htmlang doesn't know. A style whose name CSS could
5067+/// have goes to the CSS as written, with a warning; anything else (a flag,
5068+/// a name that isn't a word) is an error. Returns whether it is kept.
5069+fn unknown_attribute(
5073+ column: Option<usize>,
5074+ after_another: bool,
1819 ctx: &mut ParseContext,
5076 ctx: &mut ParseContext,
1820−) -> Result<(Vec<Attribute>, String), ParseError> {
5077+) -> bool {
1821− parse_attr_brackets_inner(input, line_num, ctx, true)
5078+ // `@td padding 8`: an element prefix without its colon
5079+ if let Some(name) = base.strip_prefix('@')
5080+ && crate::ast::ElementKind::from_name(name).is_some()
5082+ let example = match attr.value.as_deref() {
5083+ Some(value) => format!("{}:{}", attr.key, value.trim()),
5084+ None => format!("{}:padding 8", attr.key),
5086+ let diagnostic = Diagnostic::error(
5087+ code::UNKNOWN_ATTRIBUTE,
5090+ "unknown attribute '{}': an element prefix ends in a colon, as in `{}`",
5095+ let diagnostic = at_attribute(diagnostic, column, ctx);
5096+ ctx.diagnostics.push(diagnostic);
5099+ // `[card]` where `card` is a bundle: it is used as `$card`
5100+ if attr.value.is_none() && ctx.env.bundle(base).is_some() && base == attr.key {
5101+ ctx.used_defines.insert(base.to_string());
5102+ let diagnostic = Diagnostic::error(
5103+ code::UNKNOWN_ATTRIBUTE,
5106+ "unknown attribute '{}': '{}' is an attribute bundle, used as `${}`",
5111+ .suggest(Some(format!("${}", base)));
5112+ let diagnostic = at_attribute(diagnostic, column, ctx);
5113+ ctx.diagnostics.push(diagnostic);
5116+ // `hover:title x`: an HTML attribute's name is not a suggestion for
5119+ suggest_closest(base, &crate::vocab::all_attributes()).filter(|&closest| closest != base);
5120+ let mut message = match (&suggestion, error) {
5121+ (Some(closest), true) => {
5123+ "unknown attribute '{}', did you mean '{}'?",
5127+ (None, true) => format!("unknown attribute '{}'", attr.key),
5128+ (Some(closest), false) => format!(
5129+ "unknown CSS property '{}', did you mean '{}'? It is written to the CSS as it is",
5132+ (None, false) => format!(
5133+ "unknown CSS property '{}': it is written to the CSS as it is",
5137+ // `box-shadow 0 1px red, 0 2px blue` or `font-family Inter,
5138+ // sans-serif`: the comma ended the attribute, and the rest of the
5139+ // value became one
5140+ let rest_of_a_value = !base.starts_with(|c: char| c.is_ascii_alphabetic() || c == '-')
5141+ || (suggestion.is_none() && attr.value.is_none() && after_another);
5142+ if rest_of_a_value && error {
5143+ if !message.ends_with('?') {
5146+ message.push_str(" A comma separates attributes: to keep one in a value, write `\\,`");
5148+ let severity = if error {
5153+ let diagnostic = Diagnostic::new(code::UNKNOWN_ATTRIBUTE, severity, line, message)
5155+ .suggest(suggestion);
5156+ let diagnostic = at_attribute(diagnostic, column, ctx);
5157+ ctx.diagnostics.push(diagnostic);
1824−fn parse_attr_brackets_no_validate(
5161+/// Evaluate the attributes of a list: bundles are spliced in, `if()`
1825− input: &str,
5162+/// chooses, and variables fill values. A variable fills only the value it
5163+/// is written in: attributes come from bundles, never from text. With
5164+/// `validate`, unknown names and invalid values are reported. `text_keys`
5165+/// are a called function's parameters: their values are text rather than
5166+/// CSS, and they aren't checked as attributes.
5168+ tokens: &[syntax::Attr],
1826 line_num: usize,
5169 line_num: usize,
1827 ctx: &mut ParseContext,
5170 ctx: &mut ParseContext,
1828−) -> Result<(Vec<Attribute>, String), ParseError> {
5171+ validate: bool,
1829− parse_attr_brackets_inner(input, line_num, ctx, false)
5172+ text_keys: &[String],
5173+) -> Vec<Attribute> {
5174+ parse_attrs(tokens, line_num, ctx, validate, text_keys)
5176+ .map(|(attr, _)| attr)
1832−fn parse_attr_brackets_inner(
5180+/// [`parse_attr_list`], with the value of each attribute whose key is one
1833− input: &str,
5181+/// of `text_keys` (a call's parameters) as a value with its type (see
5182+/// [`ParseContext::slot_value`]), so a parameter can get a list or a
5185+ tokens: &[syntax::Attr],
1834 line_num: usize,
5186 line_num: usize,
1835 ctx: &mut ParseContext,
5187 ctx: &mut ParseContext,
1836 validate: bool,
5188 validate: bool,
1837−) -> Result<(Vec<Attribute>, String), ParseError> {
5189+ text_keys: &[String],
1838− let mut depth = 0;
5190+) -> Vec<(Attribute, Option<Value>)> {
1839− let mut end_pos = 0;
5191+ let mut read = ReadAttrs::default();
1840−
5192+ read_attrs(tokens, "", line_num, ctx, validate, text_keys, &mut read);
1841− for (i, c) in input.char_indices() {
5193+ read.attrs
1856− return Err(ParseError {
1858− message: "unclosed '[' in attribute list".to_string(),
1862− let attrs_inner = &input[1..end_pos];
1863− let remaining = input[end_pos + 1..].trim().to_string();
1864− let attrs = parse_attr_list(attrs_inner, line_num, ctx, validate);
1866− Ok((attrs, remaining))
1869−fn is_valid_hex_color(s: &str) -> bool {
5196+/// The attributes of a list read so far, and the keys written (for the
1870− if !s.starts_with('#') {
5197+/// duplicate check).
1871− return true; // Not a hex color, skip
5198+#[derive(Default)]
1872− }
5199+struct ReadAttrs {
1873− let hex = &s[1..];
5200+ attrs: Vec<(Attribute, Option<Value>)>,
1874− matches!(hex.len(), 3 | 4 | 6 | 8) && hex.chars().all(|c| c.is_ascii_hexdigit())
5201+ seen_keys: Vec<(String, bool)>,
1877−fn parse_attr_list(
5204+/// [`parse_attrs`] for the attributes of `tokens`, each under the prefixes
1878− input: &str,
5205+/// `prefix` (`md:` for those of `md:[...]`), which distribute over a
5206+/// group, a bundle and the branch an `if()` takes. Only styles take a
5207+/// prefix, so an HTML attribute there is an error.
5209+ tokens: &[syntax::Attr],
1879 line_num: usize,
5211 line_num: usize,
1880 ctx: &mut ParseContext,
5212 ctx: &mut ParseContext,
1881 validate: bool,
5213 validate: bool,
1882−) -> Vec<Attribute> {
5214+ text_keys: &[String],
1883− let mut attrs = Vec::new();
5215+ out: &mut ReadAttrs,
1884− let mut seen_keys: Vec<String> = Vec::new();
5216+) {
1885−
5217+ let mut chosen = Vec::new();
1886− for part in split_commas(input) {
5218+ choose_attrs(
1887− let part = part.trim();
5219+ tokens,
1888− // A whole attribute `if(cond, a, b)` is the chosen branch's text.
5220+ prefix,
1889− let chosen;
5221+ line_num,
1890− let part = match choose_if(part, ctx, line_num) {
5222+ ctx,
1891− Some(branch) => {
5223+ validate,
1892− chosen = branch;
5224+ text_keys,
1893− chosen.as_str()
5225+ &mut chosen,
5228+ for token in &chosen {
5229+ let line = if token.span.line == 0 {
1897− if part.is_empty() {
5234+ let (key, value, html) = (token.key.clone(), token.value.clone(), token.html);
5235+ let column = |at: usize| Some(token.span.column + at);
5237+ // `md:[...]`, `md:$card`, `md:if(...)`: the prefixes apply to each
5238+ // attribute there, and a prefix a parameter can't have
5239+ if let Some(prefixed) = &token.prefixed {
5240+ if let Some(inner) = group_prefix(token, prefixed, prefix, line, ctx) {
5242+ prefixed.target.attrs(),
1898 continue;
5251 continue;
1901− // $define reference — expand attribute bundle
5254+ // `$name` (or `${name}`) alone: an attribute bundle, spliced in
1902− if let Some(name) = part.strip_prefix('$')
5255+ let bundle = key.strip_prefix('$').filter(|_| value.is_none() && !html);
1903− && let Some(define_attrs) = ctx.defines.get(name)
5256+ let bundle = bundle.and_then(|after| match interp::reference(after, &ctx.env)? {
1904− {
5257+ (interp::Reference::Var(name), len) if len == after.len() => Some(name),
1905− ctx.used_defines.insert(name.to_string());
5258+ _ => None,
1906− attrs.extend(define_attrs.clone());
5259+ });
5260+ if let Some(name) = bundle {
5261+ if let Some(define_attrs) = ctx.env.bundle(&name).cloned() {
5262+ ctx.used_defines.insert(name.clone());
5263+ for attr in define_attrs.iter() {
5264+ if !prefix.is_empty() {
5265+ let prefixed = Attribute {
5266+ key: format!("{}{}", prefix, attr.key),
5269+ if prefixed_parameter(&prefixed, text_keys, line, column(0), validate, ctx)
5273+ if let Some(attr) =
5274+ prefixed_member(attr, prefix, &name, line, column(0), validate, ctx)
5276+ out.attrs.push((attr, None));
5280+ let attrs = &out.attrs;
5281+ // Checked here, where it is either a parameter or not
5282+ let checked_here = validate
5284+ && could_be_parameter(attr)
5285+ && !text_keys.contains(&attr.key);
5287+ && (misspelled_parameter(attr, text_keys, line, column(0), ctx)
5288+ || !check_attribute(attr, line, column(0), !attrs.is_empty(), ctx))
5292+ out.attrs.push((attr.clone(), None));
5295+ not_a_bundle(&name, line, column(0), ctx);
5299+ // A name never comes from a variable
5300+ if key.contains('$') {
5301+ track_var_refs(&key, &mut ctx.used_variables);
5302+ ctx.diagnostics.push(
5304+ code::ATTRIBUTE_FROM_VARIABLE,
5307+ "'{}': an attribute's name can't come from a variable. A variable \
5308+ fills a value (`padding $size`), and whole attributes come from a \
5309+ bundle (`@let name [padding 8]`, used as `[$name]`)",
5313+ .subject(key.as_str()),
1907 continue;
5315 continue;
1910− track_var_refs(part, &mut ctx.used_variables);
5318+ // Only a style has states: `md:[id=x]`, `md:id=x`
1911−
5319+ if html && (!prefix.is_empty() || !crate::vocab::split_prefixes(&key).0.is_empty()) {
1912− // A value `if(cond, a, b)` picks `a` or `b` (free text) by `cond`;
5320+ let written = format!("{}{}", prefix, key);
1913− // an empty choice leaves the attribute out.
5321+ let (name, _) = crate::vocab::split_prefixes(&written);
1914− let Some(part) = choose_if_value(part, ctx, line_num) else {
5322+ let diagnostic = Diagnostic::error(
5323+ code::INVALID_PREFIX,
5326+ "'{}=': a prefix applies to a style, and `{}=` is an HTML attribute, \
5327+ which has no states",
5329+ &written[name.concat().len()..]
5332+ .subject(token.key.as_str());
5333+ let diagnostic = at_attribute(diagnostic, column(0), ctx);
5334+ ctx.diagnostics.push(diagnostic);
1915 continue;
5335 continue;
5337+ let key = if prefix.is_empty() {
5340+ format!("{}{}", prefix, key)
1917− let part = substitute_vars(&part, &ctx.variables);
1919− let attr = if let Some((key, value)) = split_html_attribute(&part) {
5343+ // A value's variables are filled in. A style's value is CSS, where
1920− Attribute {
5344+ // quoted text keeps its quotes; an HTML attribute's (and a
1921− key: key.to_string(),
5345+ // parameter's) is text, where it loses them.
1922− value: Some(value.to_string()),
5346+ let sink = if html || text_keys.contains(&key) {
1923− html: true,
5347+ Sink::Text
1925− } else if let Some((key, value)) = part.split_once(' ') {
1926− let value = value.trim().to_string();
1928− key: key.trim().to_string(),
1929− value: Some(value),
1932 } else {
5348 } else {
1933− Attribute {
5349+ Sink::Css
1934− key: part.to_string(),
5350+ };
1935− value: None,
5351+ let mut filled = true;
1936− html: false,
5352+ let mut quoted = None;
5353+ let mut typed = None;
5354+ let value = match value {
5356+ // A parameter's value keeps its type
5357+ Some(value) if !html && text_keys.contains(&key) => {
5358+ let at = column(token.raw.len() - value.len());
5359+ let (value, ok) = ctx.slot_value(&value, line, at);
5361+ if let Value::Quoted(q) = &value {
5362+ quoted = Some(q.clone());
5364+ let text = value.to_string();
5365+ typed = Some(value);
5369+ let at = column(token.raw.len() - value.len());
5370+ let (text, is_quoted, ok) = ctx.fill_value(&value, line, at, sink);
5372+ quoted = is_quoted;
5376+ let attr = Attribute {
5382+ // A value that couldn't be filled in is already reported, and a
5383+ // parameter's value is text for the function
5384+ let validate = validate && filled && !text_keys.contains(&attr.key);
1940− // Warn on duplicate attributes (compare full key so pseudo-class
5386+ // A duplicate is reported (compare the full key, so `border` and
1941− // variants like `border` and `hover:border` are not conflated)
5387+ // `hover:border` differ, and the form, so `width=800` and
5388+ // `width 200` do too), and the later one wins
1942 if validate {
5389 if validate {
1943− if seen_keys.contains(&attr.key) {
5390+ let seen = (normal_key(&attr.key), attr.html);
1944− ctx.diagnostics.push(Diagnostic {
5391+ if out.seen_keys.contains(&seen) {
1945− line: line_num,
5392+ let message = if attr.html {
1946− column: None,
5393+ format!("duplicate attribute '{}='", attr.key)
1947− message: format!("duplicate attribute '{}'", attr.key),
5394+ } else {
1948− severity: Severity::Warning,
5395+ format!("duplicate attribute '{}': the later one wins", attr.key)
1949− source_line: None,
5396+ };
1950− });
5397+ let diagnostic = Diagnostic::warning(code::DUPLICATE_ATTRIBUTE, line, message)
5398+ .subject(attr.key.as_str());
5399+ let diagnostic = at_attribute(diagnostic, column(0), ctx);
5400+ ctx.diagnostics.push(diagnostic);
1951 } else {
5401 } else {
1952− seen_keys.push(attr.key.clone());
5402+ out.seen_keys.push(seen);
1955− // Color validation for hex colors
5406+ if validate && misspelled_parameter(&attr, text_keys, line, column(0), ctx) {
1956− if !attr.html
5407+ continue;
1957− && matches!(
5408+ }
1958− crate::vocab::base_attribute(&attr.key),
5409+ if prefixed_parameter(&attr, text_keys, line, column(0), validate, ctx) {
1959− "background" | "color"
5410+ continue;
1961− && let Some(ref val) = attr.value
5412+ if validate && attr.html && attr.key == "class" {
1962− && val.starts_with('#')
5413+ reserved_class(&attr, line, column(0), ctx);
1963− && !is_valid_hex_color(val)
5414+ }
1964− {
5415+ // `padding=4`: a style written as an HTML attribute, which the
1965− ctx.diagnostics.push(Diagnostic {
5416+ // browser ignores (`width=` and `height=` are real on some
1966− line: line_num,
5417+ // elements, see `validate_tree`)
1967− column: None,
5418+ if validate
1968− message: format!("invalid hex color '{}'", val),
5419+ && attr.html
1969− severity: Severity::Warning,
5420+ && crate::vocab::is_style_attribute(&attr.key)
1970− source_line: None,
5421+ && !crate::vocab::HTML_ATTRIBUTES.contains(&attr.key.as_str())
1972− }
5423+ let value = token.value.as_deref().unwrap_or("").trim();
5424+ let diagnostic = Diagnostic::warning(
5425+ code::HTML_ATTRIBUTE_FORM,
5428+ "'{0}={1}' is an HTML attribute, but {0} is a style: write `{0} {1}`",
5432+ .subject(token.raw.as_str())
5433+ .suggest(Some(format!("{} {}", attr.key, value)));
5434+ let diagnostic = at_attribute(diagnostic, column(0), ctx);
5435+ ctx.diagnostics.push(diagnostic);
1975− // Warn on unknown attributes. `key=value` HTML attributes may use any
5438+ // A style or a flag: its name is checked, and what can't be
1976− // name; everything else must be a known style.
5439+ // written into the page is an error and left out
1977− if validate && !attr.html {
5440+ let checked = validate && !attr.html && !(ctx.in_bundle && could_be_parameter(&attr));
1978− let base_key = crate::vocab::base_attribute(attr.key.as_str());
5441+ let after_another = !out.attrs.is_empty();
1979− let is_boolean_html =
5442+ if checked && !check_attribute(&attr, line, column(0), after_another, ctx) {
1980− attr.value.is_none() && crate::vocab::BOOLEAN_HTML_ATTRS.contains(&base_key);
5443+ continue;
1981− if is_boolean_html || crate::vocab::is_style_attribute(base_key) {
1982− validate_attr_value(&attr, line_num, ctx);
1983− } else if crate::vocab::HTML_ATTRIBUTES.contains(&base_key)
1984− || base_key.starts_with("aria-")
1985− || base_key.starts_with("data-")
1987− ctx.diagnostics.push(Diagnostic {
1991− "'{}' is an HTML attribute: write `{}={}`",
1994− attr.value.as_deref().unwrap_or("")
1996− severity: Severity::Warning,
2000− let suggestion = suggest_closest(base_key, &crate::vocab::all_attributes());
2001− let msg = match suggestion {
2004− "unknown attribute '{}', did you mean '{}'?",
2008− None => format!("unknown attribute '{}'", attr.key),
2010− ctx.diagnostics.push(Diagnostic {
2014− severity: Severity::Warning,
2020− attrs.push(attr);
5446+ out.attrs.push((attr, typed));
2026−/// Split an HTML attribute written `key=value` (`alt=`, `type=email`,
5450+/// At a call, a parameter under prefixes (`md:title x`, `md:[title x]`):
2027−/// `aria-label=Close menu`). Returns `None` for style attributes.
5451+/// a parameter has one value, with no states, so it is reported (with
2028−fn split_html_attribute(part: &str) -> Option<(&str, &str)> {
5452+/// `validate`) and left out; returns true then. A parameter named like a
2029− let first_token = part.split(char::is_whitespace).next()?;
5453+/// style (`color`) is a style under a prefix, for the root element.
2030− let eq = first_token.find('=')?;
5454+fn prefixed_parameter(
2031− let key = &part[..eq];
5455+ attr: &Attribute,
2032− let valid_key = key.starts_with(|c: char| c.is_ascii_alphabetic())
5456+ text_keys: &[String],
2033− && key
5457+ line: usize,
2034− .chars()
5458+ column: Option<usize>,
2035− .all(|c| c.is_ascii_alphanumeric() || matches!(c, '-' | '_' | '.'));
5459+ validate: bool,
2036− valid_key.then(|| (key, part[eq + 1..].trim()))
5460+ ctx: &mut ParseContext,
5462+ let (prefixes, name) = crate::vocab::split_prefixes(&attr.key);
5464+ || prefixes.is_empty()
5465+ || !text_keys.iter().any(|k| k == name)
5466+ || crate::vocab::is_style_attribute(name)
5471+ let what = if ctx.in_page {
5476+ let diagnostic = Diagnostic::error(
5477+ code::INVALID_PREFIX,
5480+ "'{}': `{}` is {}, which has one value, and a prefix applies to a style, \
5482+ attr.key, name, what
5485+ .subject(attr.key.as_str());
5486+ let diagnostic = at_attribute(diagnostic, column, ctx);
5487+ ctx.diagnostics.push(diagnostic);
2039−fn split_commas(input: &str) -> Vec<&str> {
5492+/// The prefixes of a prefixed group, bundle or `if()` inside `outer` (the
2040− let mut parts = Vec::new();
5493+/// prefixes of the groups it is in), when they are all known; else the
2041− let mut start = 0;
5494+/// unknown one is reported. Text after a group's `]` is an error too.
2042− let mut depth = 0;
5495+fn group_prefix(
2043− let mut in_quotes = false;
5496+ token: &syntax::Attr,
2044−
5497+ prefixed: &syntax::Prefixed,
2045− for (i, c) in input.char_indices() {
5498+ outer: &str,
2046− match c {
5499+ line: usize,
2047− '"' => in_quotes = !in_quotes,
5500+ ctx: &mut ParseContext,
2048− _ if in_quotes => {}
5501+) -> Option<String> {
2049− '[' | '(' => depth += 1,
5502+ let at = |ctx: &ParseContext, diagnostic: Diagnostic, span: syntax::Span| match &ctx
2050− ']' | ')' => depth -= 1,
5503+ .current_source
2051− ',' if depth == 0 => {
5504+ {
2052− parts.push(&input[start..i]);
5505+ (current, Some(text)) if span.line != 0 && *current == span.line => {
2053− start = i + 1;
5506+ diagnostic.column(span.column).source(text.clone())
5510+ if let syntax::Branch::Group {
5511+ trailing: Some(trailing),
5513+ } = &prefixed.target
5515+ let diagnostic = Diagnostic::error(
5516+ code::UNEXPECTED_ARGUMENT,
5519+ "'{}' after the `]` of `{}[...]`: the prefixes apply to the attributes in the \
5520+ group, so it goes inside it",
5521+ trailing.raw, prefixed.prefix
5524+ .subject(trailing.raw.as_str());
5525+ let diagnostic = at(ctx, diagnostic, trailing.span);
5526+ ctx.push_once(diagnostic);
5528+ let (known, rest) = crate::vocab::split_prefixes(&prefixed.prefix);
5529+ if !rest.is_empty() {
5530+ let problem = unknown_prefix(rest).unwrap_or_else(|| {
5531+ let written = rest.split_inclusive(':').next().unwrap_or(rest);
5533+ message: format!("unknown prefix '{}'", written),
5534+ subject: written.to_string(),
5538+ let diagnostic = Diagnostic::error(code::UNKNOWN_PREFIX, line, problem.message)
5539+ .subject(problem.subject)
5540+ .suggest(problem.suggestion);
5541+ let diagnostic = at(ctx, diagnostic, token.span);
5542+ ctx.push_once(diagnostic);
2058− parts.push(&input[start..]);
5545+ Some(format!("{}{}", outer, known.concat()))
2062−// ---------------------------------------------------------------------------
5548+/// An attribute of the bundle `bundle`, spliced in under `prefix`
2063−// Chain splitting (the > operator)
5549+/// (`md:$card`): the same attribute with the prefixes in front, when it can
2064−// ---------------------------------------------------------------------------
5550+/// take them. An HTML attribute can't; a style's prefixes are checked, as
2065−
5551+/// is a flag or a name that isn't a style (a bundle's parameter), which
2066−fn split_chain(content: &str) -> Vec<String> {
5552+/// under a prefix are attributes like any other.
2067− let mut segments = Vec::new();
5553+fn prefixed_member(
2068− let mut current = String::new();
5554+ attr: &Attribute,
2069− let chars: Vec<char> = content.chars().collect();
5555+ prefix: &str,
2070− let mut i = 0;
5556+ bundle: &str,
2071− let mut bracket_depth = 0;
5557+ line: usize,
2072−
5558+ column: Option<usize>,
2073− while i < chars.len() {
5559+ validate: bool,
2074− if chars[i] == '[' {
5560+ ctx: &mut ParseContext,
2075− bracket_depth += 1;
5561+) -> Option<Attribute> {
5562+ let key = format!("{}{}", prefix, attr.key);
5565+ let diagnostic = Diagnostic::error(
5566+ code::INVALID_PREFIX,
5569+ "'{}${}': the bundle has `{}=`, an HTML attribute, and a prefix applies to \
5570+ styles, which have states",
5571+ prefix, bundle, attr.key
5574+ .subject(format!("{}${}", prefix, bundle));
5575+ let diagnostic = at_attribute(diagnostic, column, ctx);
5576+ ctx.diagnostics.push(diagnostic);
2077− if chars[i] == ']' {
5578+ return None;
2078− bracket_depth -= 1;
5579+ }
5580+ let prefixed = Attribute {
5585+ let fine = if attr.value.is_none() || could_be_parameter(attr) {
5586+ check_attribute(&prefixed, line, column, false, ctx)
5588+ check_prefixes(&prefixed, line, column, ctx)
2081− // Match " > @" outside brackets
5597+/// `class=hl-x`: the `hl-` prefix is htmlang's, for its generated classes,
2082− if bracket_depth == 0
5598+/// whose rules would then apply to the element too. It goes into the page
2083− && i + 3 < chars.len()
5599+/// as written, so this is a warning.
2084− && chars[i] == ' '
5600+fn reserved_class(attr: &Attribute, line: usize, column: Option<usize>, ctx: &mut ParseContext) {
2085− && chars[i + 1] == '>'
5601+ let classes = attr.value.as_deref().unwrap_or_default();
2086− && chars[i + 2] == ' '
5602+ for class in classes.split_whitespace() {
2087− && chars[i + 3] == '@'
5603+ if class.starts_with(crate::codegen::CLASS_PREFIX) {
2088− {
5604+ let diagnostic = Diagnostic::warning(
2089− segments.push(current.trim().to_string());
5605+ code::INVALID_VALUE,
2090− current = String::new();
5606+ line,
2091− i += 3; // skip " > ", keep the "@"
5607+ format!(
2092− continue;
5608+ "class '{}' starts with `{}`, which htmlang keeps for the classes it \
5609+ generates, so their styles could apply to this element: give it \
5612+ crate::codegen::CLASS_PREFIX
5616+ let diagnostic = at_attribute(diagnostic, column, ctx);
5617+ ctx.diagnostics.push(diagnostic);
2095− current.push(chars[i]);
2099− if !current.trim().is_empty() {
5622+/// A style's key as the CSS reads it, for finding duplicates: its at-rule
2100− segments.push(current.trim().to_string());
5623+/// prefixes in one order (`dark:md:` is `md:dark:`), then its selector
5624+/// prefixes as written, whose order is the selector's.
5625+fn normal_key(key: &str) -> String {
5626+ let (prefixes, name) = crate::vocab::split_prefixes(key);
5627+ let mut at: Vec<(usize, &str)> = prefixes
5629+ .filter_map(|p| crate::vocab::at_rule_rank(p).map(|rank| (rank, *p)))
5631+ at.sort_unstable();
5633+ let mut normal: String = at.iter().map(|(_, p)| *p).collect();
5634+ for prefix in prefixes
5636+ .filter(|p| crate::vocab::at_rule_rank(p).is_none())
5638+ normal.push_str(prefix);
5640+ normal.push_str(name);
2103− segments
5644+/// `[$name]` where `$name` isn't an attribute bundle.
5645+fn not_a_bundle(name: &str, line: usize, column: Option<usize>, ctx: &mut ParseContext) {
5646+ track_var_refs(&format!("${}", name), &mut ctx.used_variables);
5647+ let is_value = interp::name_len(name) > 0 && interp::resolve(name, &ctx.env).is_some();
5648+ let diagnostic = if is_value {
5650+ code::ATTRIBUTE_FROM_VARIABLE,
5653+ "'${}' is a value, not an attribute: attributes come from a bundle \
5654+ (`@let name [padding 8]`, used as `[$name]`), and a value fills an \
5655+ attribute's value (`padding ${}`)",
5660+ } else if ctx.env.function(name).is_some() {
5661+ ctx.used_functions.insert(name.to_string());
5663+ code::UNDEFINED_VARIABLE,
5666+ "'${}' is a function, not an attribute bundle: it is called as an element, \
5673+ let mut bundles = ctx.env.bundle_names();
5674+ bundles.sort_unstable();
5675+ let suggestion = suggest_closest(name, &bundles);
5676+ let message = match suggestion {
5677+ Some(closest) => format!(
5678+ "undefined attribute bundle '${}', did you mean '${}'?",
5681+ None => format!("undefined attribute bundle '${}'", name),
5683+ Diagnostic::error(code::UNDEFINED_VARIABLE, line, message)
5685+ .suggest(suggestion)
5687+ let diagnostic = match (&ctx.current_source, column) {
5688+ ((current, Some(text)), Some(column)) if *current == line => {
5689+ diagnostic.column(column).source(text.clone())
5693+ ctx.diagnostics.push(diagnostic);
2106// ---------------------------------------------------------------------------
5696// ---------------------------------------------------------------------------
2107// Text segment parsing (inline {...} elements)
5697// Text segment parsing (inline {...} elements)
2108// ---------------------------------------------------------------------------
5698// ---------------------------------------------------------------------------
2110−/// Escapes in text: `\@`, `\$`, `\{`, `\--` and `\\` stand for the
5700+/// While a slot is filled in, each escape (see [`syntax::ESCAPES`]) is a
2111−/// character(s) themselves. While a text is processed, each is a private-use
5701+/// private-use placeholder, U+E000 plus its place in the table, so it
2112−/// placeholder, so it can't start a variable, an inline element or a line.
5702+/// can't start a variable, a quote or an inline element. Afterwards it
2113−const ESCAPES: &[(&str, char, &str)] = &[
5703+/// becomes what it stands for.
2114− ("\\\\", '\u{E000}', "\\"),
2115− ("\\$", '\u{E001}', "$"),
2116− ("\\{", '\u{E002}', "{"),
2117− ("\\@", '\u{E003}', "@"),
2118− ("\\--", '\u{E004}', "--"),
2121fn protect_escapes(text: &str) -> String {
5704fn protect_escapes(text: &str) -> String {
2122 if !text.contains('\\') {
5705 if !text.contains('\\') {
2123 return text.to_string();
5706 return text.to_string();
2125− let mut out = text.to_string();
5708+ let mut out = String::with_capacity(text.len());
2126− for (escape, placeholder, _) in ESCAPES {
5709+ let mut i = 0;
2127− out = out.replace(escape, &placeholder.to_string());
5710+ while let Some(c) = text[i..].chars().next() {
5711+ let len = syntax::escape_len(&text[i..]);
5717+ let escape = &text[i..i + len];
5718+ let index = syntax::ESCAPES.iter().position(|e| *e == escape);
5719+ out.extend(index.and_then(|n| char::from_u32(0xE000 + n as u32)));
5725+/// The escape a placeholder stands for, as written (`\,`).
5726+fn escape_of(c: char) -> Option<&'static str> {
5727+ let index = (c as u32).checked_sub(0xE000)?;
5728+ syntax::ESCAPES.get(index as usize).copied()
2132fn restore_escapes(text: &str) -> String {
5731fn restore_escapes(text: &str) -> String {
2133− let mut out = text.to_string();
5732+ text.chars()
2134− for (_, placeholder, literal) in ESCAPES {
5733+ .fold(String::with_capacity(text.len()), |mut out, c| {
2135− out = out.replace(*placeholder, literal);
5734+ match escape_of(c) {
5735+ // What the escape stands for: what follows the backslash
5736+ Some(escape) => out.push_str(&escape[1..]),
5737+ None => out.push(c),
5743+/// Inside the quoted strings of a CSS value, `\"` and `\\` mean in CSS what
5744+/// they mean in htmlang, so they stay as written there.
5745+fn keep_css_string_escapes(protected: &str) -> String {
5746+ let mut out = String::with_capacity(protected.len());
5747+ let mut inside = false;
5748+ for c in protected.chars() {
5749+ match escape_of(c) {
5750+ Some(escape @ ("\\\"" | "\\\\")) if inside => out.push_str(escape),
2140−fn parse_text_segments(input: &str, ctx: &mut ParseContext) -> Vec<TextSegment> {
5762+/// Evaluate text: fill in the variables of its plain runs and build its
5763+/// inline elements. Each run is one slot, so a value can't make markup.
5764+fn text_segments(text: &syntax::Text, ctx: &mut ParseContext) -> Vec<TextSegment> {
2141 let mut segments = Vec::new();
5765 let mut segments = Vec::new();
2142− let mut current_text = String::new();
5766+ // The plain text so far, and where it starts
2143− let chars: Vec<char> = protect_escapes(input).chars().collect();
5767+ let mut plain = String::new();
2144− let mut i = 0;
5768+ let mut start: Option<syntax::Span> = None;
2145−
5769+ let flush = |plain: &mut String,
2146− while i < chars.len() {
5770+ start: &mut Option<syntax::Span>,
2147− if chars[i] == '{' && i + 1 < chars.len() && chars[i + 1] == '@' {
5771+ segments: &mut Vec<TextSegment>,
2148− // Flush accumulated plain text
5772+ ctx: &mut ParseContext| {
2149− if !current_text.is_empty() {
5773+ if !plain.is_empty() {
2150− segments.push(TextSegment::Plain(restore_escapes(&substitute_vars(
5774+ let at = start.unwrap_or(text.span);
2151− ¤t_text,
5775+ let filled = ctx.interpolate_text(plain, at.line, Some(at.column));
2152− &ctx.variables,
5776+ segments.push(TextSegment::Plain(filled));
2153− ))));
5777+ plain.clear();
2154− current_text.clear();
5778+ }
2155− }
5779+ *start = None;
2157− // Find matching }
5781+ for segment in &text.segments {
2158− let mut depth = 0;
5782+ match segment {
2159− let start = i + 1; // after {
5783+ Segment::Plain { raw, span } => {
2160− i += 1;
5784+ start.get_or_insert(*span);
2161− loop {
5785+ plain.push_str(raw);
2162− if i >= chars.len() {
2165− if chars[i] == '{' {
2167− } else if chars[i] == '}' {
2175−
5787+ Segment::Inline(inline) => {
2176− let inner: String = chars[start..i].iter().collect();
5788+ let line = ctx.current_line;
2177− i += 1; // skip }
5789+ match resolve(&inline.head, inline.text.as_ref(), line, &text.raw, ctx) {
2178−
5790+ Ok(resolved) => {
2179− match parse_single_element(&inner, ctx.current_line, ctx) {
5791+ if !inline.closed {
2180− Ok(elem) => segments.push(TextSegment::Inline(elem)),
5792+ let d = Diagnostic::warning(
2181− Err(e) => {
5793+ code::UNCLOSED_BRACKET,
2182− // Keep the braces as literal text, but flag what looks
5794+ inline.span.line,
2183− // like a mistyped inline element.
5795+ format!(
2184− if inner.trim_start().starts_with('@') {
5796+ "unclosed `{{`: the inline @{} runs to the end of the line. \
2185− ctx.diagnostics.push(Diagnostic {
5797+ An inline element ends with `}}` (a brace that is text is \
2186− line: ctx.current_line,
5798+ written `\\{{`)",
2187− column: None,
5799+ inline.head.name
2188− message: e.message,
5800+ ),
2189− severity: Severity::Warning,
5801+ );
2190− source_line: Some(input.to_string()),
5802+ let d = at_attribute(d, Some(inline.span.column), ctx);
2191− });
5803+ ctx.push_once(d);
5805+ flush(&mut plain, &mut start, &mut segments, ctx);
5806+ // A function called inline gets no children: its
5807+ // content is the text after its attributes
5808+ match Evaluator.complete(resolved, Vec::new(), ctx) {
5809+ Ok(nodes) => segments.extend(inline_segments(nodes, line)),
5812+ .get_or_insert_with(|| text.raw.as_str().into());
5813+ ctx.diagnostics.push(e);
5818+ // A misspelled element is an error inline too (a
5819+ // brace that is text is written `\{`); the braces
5821+ e.source_line = Some(text.raw.as_str().into());
5822+ ctx.diagnostics.push(e);
5823+ start.get_or_insert(inline.span);
5825+ plain.push_str(&inline.raw);
2193− current_text.push('{');
2194− current_text.push_str(&inner);
2195− current_text.push('}');
2199− current_text.push(chars[i]);
5834+ flush(&mut plain, &mut start, &mut segments, ctx);
2204− if !current_text.is_empty() {
5838+/// The variable `raw` is, when it is exactly one `$name` or `${name}`.
2205− segments.push(TextSegment::Plain(restore_escapes(&substitute_vars(
5839+fn whole_reference(raw: &str, env: &Env) -> Option<String> {
2206− ¤t_text,
5840+ let after = raw.trim().strip_prefix('$')?;
2207− &ctx.variables,
5841+ match interp::reference(after, env)? {
2208− ))));
5842+ (interp::Reference::Var(path), len) if len == after.len() => Some(path),
2214−/// The items of a text list: a range `A..B [step N]`, or comma-separated.
5847+/// The attributes of `tokens` after each whole-attribute `if()` has
2215−fn text_list_items(list: &str) -> Vec<String> {
5848+/// chosen (see [`syntax::Choice`]), in order, into `out`. The branch not
2216− if let Some((start, rest)) = list.split_once("..") {
5849+/// taken isn't evaluated; with `validate`, its attribute names are checked
2217− let (end, step) = match rest.split_once(" step ") {
5850+/// like code that doesn't run, under the prefixes `prefix` the `if()` is
2218− Some((end, step)) => (end.trim(), step.trim().parse::<i64>().unwrap_or(1).max(1)),
5851+/// under (`hover:if(...)`).
2219− None => (rest.trim(), 1),
5852+fn choose_attrs(
5853+ tokens: &[syntax::Attr],
5856+ ctx: &mut ParseContext,
5858+ text_keys: &[String],
5859+ out: &mut Vec<syntax::Attr>,
5861+ for token in tokens {
5862+ let Some(choice) = &token.choice else {
5863+ out.push(token.clone());
5866+ let Some(condition) = choice_shape(token, choice, line_num, ctx) else {
2221− if let (Ok(start), Ok(end)) = (start.trim().parse::<i64>(), end.parse::<i64>()) {
5869+ let taken = match condition.span.line {
2222− return numeric_range(start, end, step);
5870+ 0 => ctx.condition(&condition.raw, line_num, None),
5871+ line => ctx.condition(&condition.raw, line, Some(condition.span.column)),
5873+ let (chosen, other) = match taken {
5874+ true => (choice.branches.first(), choice.branches.get(1)),
5875+ false => (choice.branches.get(1), choice.branches.first()),
5877+ if let Some(other) = other {
5878+ track_var_refs(&branch_text(other), &mut ctx.used_variables);
5880+ check_branch(token, other, prefix, line_num, ctx, text_keys);
5883+ if let Some(branch) = chosen {
2226− .map(|s| s.trim().to_string())
2227− .filter(|s| !s.is_empty())
2231−/// Make `$target` (and `$target.key`, and nested lists) a copy of the list
5897+/// Report what is wrong with the shape of `if()`: an empty condition, a
2232−/// item stored under `source`.
5898+/// number of branches other than one or two, text after a group's `]`.
2233−fn bind_item(vars: &mut HashMap<String, String>, source: &str, target: &str) {
5899+/// Returns the condition when the `if()` can be evaluated.
2234− let under = |key: &str, name: &str| {
5900+fn choice_shape<'a>(
2235− key.strip_prefix(name)
5901+ token: &syntax::Attr,
2236− .is_some_and(|rest| rest.is_empty() || rest.starts_with(['.', '#']))
5902+ choice: &'a syntax::Choice,
5904+ ctx: &mut ParseContext,
5905+) -> Option<&'a syntax::Arg> {
5906+ let line = if token.span.line == 0 {
2238− vars.retain(|key, _| !under(key, target));
5911+ // The line the column points into, when it is the one being evaluated
2239− let copies: Vec<(String, String)> = vars
5912+ let source = |ctx: &ParseContext, diagnostic: Diagnostic, at: usize| match &ctx.current_source {
2240− .iter()
5913+ (current, Some(text)) if *current == at => diagnostic.source(text.clone()),
2241− .filter(|(key, _)| under(key, source))
5914+ _ => diagnostic,
2242− .map(|(key, value)| (format!("{}{}", target, &key[source.len()..]), value.clone()))
5915+ };
2243− .collect();
5916+ for branch in &choice.branches {
2244− vars.extend(copies);
5917+ if let syntax::Branch::Group {
2245− // A record has no text of its own
5918+ trailing: Some(trailing),
2246− vars.entry(target.to_string()).or_default();
5919+ ..
2249−/// Inclusive integer range from `start` to `end` (counting down when
5922+ let diagnostic = source(
2250−/// `start > end`), stepping by `step`. Stops instead of overflowing.
5923+ ctx,
2251−fn numeric_range(start: i64, end: i64, step: i64) -> Vec<String> {
5924+ Diagnostic::error(
2252− let mut items = Vec::new();
5925+ code::UNEXPECTED_ARGUMENT,
2253− let mut n = start;
5926+ trailing.span.line,
2254− if start <= end {
5927+ format!(
2255− while n <= end {
5928+ "'{}' after the `]` of a group in if(): a branch is one attribute, \
2256− items.push(n.to_string());
5929+ one `[group]` of attributes or one `$bundle`",
2257− match n.checked_add(step) {
5930+ trailing.raw
2258− Some(next) => n = next,
5931+ ),
2259− None => break,
5932+ )
2260− }
5933+ .column(trailing.span.column)
5934+ .subject(trailing.raw.as_str()),
5935+ trailing.span.line,
5937+ ctx.push_once(diagnostic);
2263− while n >= end {
5940+ match &choice.condition {
2264− items.push(n.to_string());
5941+ Some(condition) if (1..=2).contains(&choice.branches.len()) => Some(condition),
2265− match n.checked_sub(step) {
5942+ _ => {
2266− Some(next) => n = next,
5943+ let diagnostic = source(
2267− None => break,
5944+ ctx,
2268− }
5945+ Diagnostic::error(
5946+ code::INVALID_EXPRESSION,
5949+ "`{}`: if() takes a condition and one or two branches, \
5950+ `if(CONDITION, A, B)`",
5954+ .column(token.span.column),
5957+ ctx.push_once(diagnostic);
2274−/// Evaluate `if(cond, a)` or `if(cond, a, b)` when it is all of `text`,
5963+/// A branch's text, for the names it uses.
2275−/// returning the chosen branch (empty when `cond` fails and there is no `b`).
5964+fn branch_text(branch: &syntax::Branch) -> String {
2276−fn choose_if(text: &str, ctx: &mut ParseContext, line: usize) -> Option<String> {
5965+ let raws: Vec<&str> = branch.attrs().iter().map(|a| a.raw.as_str()).collect();
2277− let inner = text.strip_prefix("if(")?.strip_suffix(')')?;
5966+ raws.join(", ")
2278− let args = split_if_args(inner);
2279− // `if(a) (b)` isn't one call
2280− if split_trailing_paren(inner) || !(2..=3).contains(&args.len()) {
2283− let branch = if ctx.condition(args[0].trim(), line) {
2286− args.get(2).copied().unwrap_or("")
2288− Some(branch.trim().to_string())
2291−/// Whether the parentheses in `inner` close before its end, as in the
5969+/// Check attributes that are never evaluated (in code that doesn't run,
2292−/// inside of `if(a)(b)`.
5970+/// or the branch an `if()` didn't take), as far as they can be checked:
2293−fn split_trailing_paren(inner: &str) -> bool {
5971+/// names are, and literal values; a value with a variable depends on what
2294− let mut depth = 0i32;
5972+/// the variable holds. Each branch of an `if()` is checked on its own.
2295− let mut quote = None;
5973+fn check_attrs(tokens: &[syntax::Attr], line: usize, ctx: &mut ParseContext, text_keys: &[String]) {
2296− for c in inner.chars() {
5974+ parse_attr_list(&literal_attrs(tokens), line, ctx, true, text_keys);
2297− match c {
5975+ check_choices(tokens, "", line, ctx, text_keys);
2298− '"' | '\'' if quote == Some(c) => quote = None,
2299− '"' | '\'' if quote.is_none() => quote = Some(c),
2300− _ if quote.is_some() => {}
2314−/// Resolve a value written `if(cond, a, b)`: evaluate `cond` and keep the
5978+/// [`check_attrs`] for a branch of the `if()` `token`, under the prefixes
2315−/// chosen branch's text, or `None` when the choice is empty. Other
5979+/// `prefix` it is under: `hover:if($on, color red, [id=x])` checks
2316−/// attributes are returned unchanged.
5980+/// `hover:[id=x]`, an error whichever branch is taken.
2317−fn choose_if_value(part: &str, ctx: &mut ParseContext, line: usize) -> Option<String> {
5981+fn check_branch(
2318− let Some(pos) = part.find(['=', ' ']) else {
5982+ token: &syntax::Attr,
2319− return Some(part.to_string());
5983+ branch: &syntax::Branch,
2320− };
5984+ prefix: &str,
2321− let (head, value) = part.split_at(pos + 1);
5985+ line: usize,
2322− match choose_if(value.trim(), ctx, line) {
5986+ ctx: &mut ParseContext,
2323− Some(branch) if branch.is_empty() => None,
5987+ text_keys: &[String],
2324− Some(branch) => Some(format!("{}{}", head, branch)),
5988+) {
2325− None => Some(part.to_string()),
5989+ if prefix.is_empty() {
5990+ check_attrs(branch.attrs(), line, ctx, text_keys);
5993+ let list = syntax::AttrList {
5994+ attrs: branch.attrs().to_vec(),
5998+ let grouped = syntax::Attr {
5999+ key: prefix.to_string(),
6002+ raw: token.raw.clone(),
6005+ prefixed: Some(Box::new(syntax::Prefixed {
6006+ prefix: prefix.to_string(),
6007+ prefix_span: token.span,
6008+ target: syntax::Branch::Group {
6014+ check_attrs(std::slice::from_ref(&grouped), line, ctx, text_keys);
2329−fn split_if_args(input: &str) -> Vec<&str> {
6017+/// [`check_attrs`] for the branches of each `if()` of `tokens`, which are
2330− let mut parts = Vec::new();
6018+/// under the prefixes `prefix`, also inside a prefixed group or as a
2331− let mut start = 0;
6019+/// prefixed `if()`.
2332− let mut depth = 0;
6020+fn check_choices(
2333− let mut quote = None;
6021+ tokens: &[syntax::Attr],
2334− for (i, c) in input.char_indices() {
6022+ prefix: &str,
2335− match c {
6023+ line: usize,
2336− '"' | '\'' if quote == Some(c) => quote = None,
6024+ ctx: &mut ParseContext,
2337− '"' | '\'' if quote.is_none() => quote = Some(c),
6025+ text_keys: &[String],
2338− _ if quote.is_some() => {}
6026+) {
2339− '(' => depth += 1,
6027+ for token in tokens {
2340− ')' => depth -= 1,
6028+ if let Some(choice) = &token.choice
2341− ',' if depth == 0 => {
6029+ && choice_shape(token, choice, line, ctx).is_some()
2342− parts.push(&input[start..i]);
6030+ {
2343− start = i + 1;
6031+ for branch in &choice.branches {
6032+ check_branch(token, branch, prefix, line, ctx, text_keys);
6035+ if let Some(prefixed) = &token.prefixed {
6036+ let inner = format!("{}{}", prefix, prefixed.prefix);
6037+ check_choices(prefixed.target.attrs(), &inner, line, ctx, text_keys);
2348− parts.push(&input[start..]);
2352// ---------------------------------------------------------------------------
6042// ---------------------------------------------------------------------------
2353// Post-parse validation (context-dependent warnings)
6043// Post-parse validation (context-dependent warnings)
2354// ---------------------------------------------------------------------------
6044// ---------------------------------------------------------------------------
2356−/// Attributes that only make sense on container elements (@row, @el, @el).
2357−const CONTAINER_ONLY_ATTRS: &[&str] = &[
2368fn element_kind_name(kind: &ElementKind) -> String {
6046fn element_kind_name(kind: &ElementKind) -> String {
2369 format!("@{}", kind.name())
6047 format!("@{}", kind.name())
2372−fn is_container(kind: &ElementKind) -> bool {
6050+/// HTML elements whose start tag ends an open `<p>`: written inside a
2373− matches!(kind, ElementKind::Row | ElementKind::El)
6051+/// `@paragraph`, the browser moves them out of it. (`div` isn't here:
2374− || kind.spec().is_some_and(|spec| spec.container)
6052+/// inside text, htmlang writes its `<div>`s as `<span>`s.)
6054+const ENDS_A_PARAGRAPH: &[&str] = &[
6055+ "address", "article", "aside", "blockquote", "dd", "details", "dialog", "dl", "dt",
6056+ "fieldset", "figcaption", "figure", "footer", "form", "h1", "h2", "h3", "h4", "h5", "h6",
6057+ "header", "hgroup", "hr", "li", "main", "menu", "nav", "ol", "p", "pre", "search",
6058+ "section", "summary", "table", "ul",
6061+/// The HTML element `kind` is written as, if the browser would take it out
6063+fn ends_a_paragraph(kind: &ElementKind) -> Option<&'static str> {
6064+ let html = match kind {
6065+ ElementKind::Paragraph => "p",
6066+ ElementKind::Tag(spec) => spec.html,
6069+ ENDS_A_PARAGRAPH.contains(&html).then_some(html)
2377/// Stricter checks for `htmlang lint`, on top of the diagnostics every
6072/// Stricter checks for `htmlang lint`, on top of the diagnostics every
@@ -2381,132 +6076,171 @@ pub fn lint(nodes: &[Node]) -> Vec<Diagnostic> {
2381 fn walk(nodes: &[Node], depth: usize, out: &mut Vec<Diagnostic>) {
6076 fn walk(nodes: &[Node], depth: usize, out: &mut Vec<Diagnostic>) {
2382 for node in nodes {
6077 for node in nodes {
2383 let Node::Element(elem) = node else { continue };
6078 let Node::Element(elem) = node else { continue };
2384− let mut warn = |message: String| {
6079+ let start = out.len();
2385− out.push(Diagnostic {
6080+ let mut warn = |code: &'static str, message: String| {
2386− line: elem.line_num,
6081+ out.push(Diagnostic::warning(code, elem.line_num, message))
2389− severity: Severity::Warning,
2393 if depth > 10 {
6083 if depth > 10 {
2394− warn(format!(
6084+ warn(
2395− "deeply nested element ({} levels): consider simplifying",
6085+ code::DEEP_NESTING,
2396− depth
6086+ format!(
2397− ));
6087+ "deeply nested element ({} levels): consider simplifying",
2399− if matches!(elem.kind, ElementKind::Row | ElementKind::El) && elem.children.is_empty() {
6092+ // A function's body may draw with an empty element (a spacer,
2400− warn(format!(
6093+ // a dot): only one written in the page is flagged
2401− "empty container (@{}) has no children",
6094+ if elem.kind.layout().is_container()
2402− elem.kind.name()
6095+ && elem.children.is_empty()
2403− ));
6096+ && elem.function.is_none()
6099+ code::EMPTY_CONTAINER,
6100+ format!("empty container (@{}) has no children", elem.kind.name()),
2405 if elem.kind.is_tag("button") && !elem.attrs.iter().any(|a| a.key == "type") {
6103 if elem.kind.is_tag("button") && !elem.attrs.iter().any(|a| a.key == "type") {
2406− warn("@button missing 'type' attribute (defaults to submit)".to_string());
6104+ warn(
6105+ code::MISSING_BUTTON_TYPE,
6106+ "@button missing 'type' attribute (defaults to submit)".to_string(),
6109+ in_function_body(elem, &mut out[start..]);
2408 walk(&elem.children, depth + 1, out);
6110 walk(&elem.children, depth + 1, out);
2411 let mut out = Vec::new();
6113 let mut out = Vec::new();
2412 walk(nodes, 0, &mut out);
6114 walk(nodes, 0, &mut out);
6119+/// `in_paragraph`: the nodes are inside a `@paragraph` (and not inside a
6120+/// `@button` in it, which the browser keeps whole).
2416fn validate_tree(
6121fn validate_tree(
2417 nodes: &[Node],
6122 nodes: &[Node],
2418 parent_kind: Option<&ElementKind>,
6123 parent_kind: Option<&ElementKind>,
6124+ in_paragraph: bool,
2419 diagnostics: &mut Vec<Diagnostic>,
6125 diagnostics: &mut Vec<Diagnostic>,
2421 for node in nodes {
6127 for node in nodes {
6128+ // An element inside a line of text (`{@kbd ...}`, an inline call)
6129+ // is checked like one on a line of its own
6130+ if let Node::Text(segments) = node {
6131+ let inline: Vec<Node> = segments
6133+ .filter_map(|segment| match segment {
6134+ TextSegment::Inline(elem) => Some(Node::Element(elem.clone())),
6138+ validate_tree(&inline, parent_kind, in_paragraph, diagnostics);
2422 if let Node::Element(elem) = node {
6140 if let Node::Element(elem) = node {
6141+ let start = diagnostics.len();
6142+ dropped_by_the_element(elem, diagnostics);
6143+ if in_paragraph && let Some(html) = ends_a_paragraph(&elem.kind) {
6145+ Diagnostic::warning(
6146+ code::BLOCK_IN_PARAGRAPH,
6149+ "{0} inside @paragraph: HTML ends a <p> before a <{1}>, so the \
6150+ browser moves the <{1}> out of the paragraph. Put {0} after the \
6151+ paragraph, or use @el, @row or @grid, which are laid out inline \
6153+ element_kind_name(&elem.kind),
6157+ .subject(elem.kind.name()),
2423 for attr in &elem.attrs {
6160 for attr in &elem.attrs {
2424 let base = crate::vocab::base_attribute(&attr.key);
6161 let base = crate::vocab::base_attribute(&attr.key);
2426− && attr.value.as_deref() == Some("fill")
2427− && !matches!(parent_kind, Some(ElementKind::Row))
2429− diagnostics.push(Diagnostic {
2430− line: elem.line_num,
2432− message: "'width fill' works best inside @row; using 100% as fallback"
2434− severity: Severity::Warning,
2438− if base == "height"
2439− && attr.value.as_deref() == Some("fill")
2440− && !parent_kind.is_some_and(ElementKind::is_column)
2442− diagnostics.push(Diagnostic {
2443− line: elem.line_num,
2445− message: "'height fill' works best inside @el; using 100% as fallback"
2447− severity: Severity::Warning,
2452− // Container-only attributes on non-container elements
6163+ // htmlang's words for laying out children, on an element
2453− if CONTAINER_ONLY_ATTRS.contains(&base) && !is_container(&elem.kind) {
6164+ // that doesn't lay out its children: left out (codegen)
2454− diagnostics.push(Diagnostic {
6165+ if !attr.html
2455− line: elem.line_num,
6166+ && crate::vocab::CONTAINER_ATTRIBUTES.contains(&base)
2456− column: None,
6167+ && !elem.kind.layout().is_container()
2457− message: format!(
6168+ && !has_no_element(&elem.kind)
2458− "'{}' has no effect on {} (only works on @row, @el, @el)",
6169+ && !crate::vocab::split_prefixes(&attr.key)
2460− element_kind_name(&elem.kind)
6171+ .contains(&"children:")
2462− severity: Severity::Warning,
6173+ diagnostics.push(not_a_container(&elem.kind, elem.line_num, base));
2467 // Form-specific: placeholder only on @input/@textarea
6176 // Form-specific: placeholder only on @input/@textarea
2468 if base == "placeholder"
6177 if base == "placeholder"
2469 && !(elem.kind.is_tag("input") || elem.kind.is_tag("textarea"))
6178 && !(elem.kind.is_tag("input") || elem.kind.is_tag("textarea"))
2471− diagnostics.push(Diagnostic {
6180+ diagnostics.push(Diagnostic::new(
2472− line: elem.line_num,
6181+ code::NO_EFFECT,
2473− column: None,
6182+ Severity::Warning,
2474− message: format!(
6183+ elem.line_num,
2475 "'placeholder' has no effect on {} (only works on @input, @textarea)",
6185 "'placeholder' has no effect on {} (only works on @input, @textarea)",
2476 element_kind_name(&elem.kind)
6186 element_kind_name(&elem.kind)
2478− severity: Severity::Warning,
6188+ ));
2483− // 'for' only on @label
6191+ // 'for' only on @label and @output
2484− if base == "for" && !elem.kind.is_tag("label") {
6192+ if base == "for" && !(elem.kind.is_tag("label") || elem.kind.is_tag("output")) {
2485− diagnostics.push(Diagnostic {
6193+ diagnostics.push(Diagnostic::new(
2486− line: elem.line_num,
6194+ code::NO_EFFECT,
2487− column: None,
6195+ Severity::Warning,
2488− message: format!(
6196+ elem.line_num,
2489− "'for' has no effect on {} (only works on @label)",
6197+ format!(
6198+ "'for' has no effect on {} (only works on @label and @output)",
2490 element_kind_name(&elem.kind)
6199 element_kind_name(&elem.kind)
2492− severity: Severity::Warning,
6201+ ));
2493− source_line: None,
6202+ }
6204+ // `width=` and `height=` are HTML attributes of media and
6205+ // embedded content only; elsewhere they are styles
6207+ && (base == "width" || base == "height")
6208+ && !matches!(elem.kind, ElementKind::Image)
6210+ "video", "canvas", "iframe", "embed", "object", "input", "source",
6213+ .any(|tag| elem.kind.is_tag(tag))
6215+ let value = attr.value.as_deref().unwrap_or("");
6217+ Diagnostic::warning(
6218+ code::HTML_ATTRIBUTE_FORM,
6221+ "'{0}={1}' has no effect on {2}, which has no {0} attribute: \
6222+ the style is written `{0} {1}`",
6225+ element_kind_name(&elem.kind)
6228+ .subject(format!("{}={}", base, value)),
2497 // 'rows'/'cols' only on @textarea
6232 // 'rows'/'cols' only on @textarea
2498 if (base == "rows" || base == "cols") && !elem.kind.is_tag("textarea") {
6233 if (base == "rows" || base == "cols") && !elem.kind.is_tag("textarea") {
2499− diagnostics.push(Diagnostic {
6234+ diagnostics.push(Diagnostic::new(
2500− line: elem.line_num,
6235+ code::NO_EFFECT,
2501− column: None,
6236+ Severity::Warning,
2502− message: format!(
6237+ elem.line_num,
2503 "'{}' has no effect on {} (only works on @textarea)",
6239 "'{}' has no effect on {} (only works on @textarea)",
2505 element_kind_name(&elem.kind)
6241 element_kind_name(&elem.kind)
2507− severity: Severity::Warning,
6243+ ));
2512 // Media-specific attributes only on @video/@audio
6246 // Media-specific attributes only on @video/@audio
@@ -2521,38 +6255,35 @@ fn validate_tree(
2521 | "preload"
6255 | "preload"
2522 ) && !matches!(elem.kind.name(), "video" | "audio")
6256 ) && !matches!(elem.kind.name(), "video" | "audio")
2524− diagnostics.push(Diagnostic {
6258+ diagnostics.push(Diagnostic::new(
2525− line: elem.line_num,
6259+ code::NO_EFFECT,
2526− column: None,
6260+ Severity::Warning,
2527− message: format!(
6261+ elem.line_num,
2528 "'{}' has no effect on {} (only works on @video, @audio)",
6263 "'{}' has no effect on {} (only works on @video, @audio)",
2530 element_kind_name(&elem.kind)
6265 element_kind_name(&elem.kind)
2532− severity: Severity::Warning,
6267+ ));
2537 // Missing alt text on @image
6270 // Missing alt text on @image
2538 if matches!(elem.kind, ElementKind::Image) && !elem.attrs.iter().any(|a| a.key == "alt")
6271 if matches!(elem.kind, ElementKind::Image) && !elem.attrs.iter().any(|a| a.key == "alt")
2540− diagnostics.push(Diagnostic {
6273+ diagnostics.push(Diagnostic::new(
2541− line: elem.line_num,
6274+ code::MISSING_ALT,
2542− column: None,
6275+ Severity::Warning,
2543− message: "@image missing 'alt' attribute (accessibility)".to_string(),
6276+ elem.line_num,
2544− severity: Severity::Warning,
6277+ "@image missing 'alt' attribute (accessibility)".to_string(),
2545− source_line: None,
6278+ ));
2548 if elem.kind.is_tag("input") && !elem.attrs.iter().any(|a| a.key == "type") {
6280 if elem.kind.is_tag("input") && !elem.attrs.iter().any(|a| a.key == "type") {
2549− diagnostics.push(Diagnostic {
6281+ diagnostics.push(Diagnostic::new(
2550− line: elem.line_num,
6282+ code::MISSING_INPUT_TYPE,
2551− column: None,
6283+ Severity::Warning,
2552− message: "@input missing 'type' attribute (defaults to 'text')".to_string(),
6284+ elem.line_num,
2553− severity: Severity::Warning,
6285+ "@input missing 'type' attribute (defaults to 'text')".to_string(),
2554− source_line: None,
6286+ ));
2557 if matches!(elem.kind, ElementKind::Link) {
6288 if matches!(elem.kind, ElementKind::Link) {
2558 // For @link, argument is the URL, not text content
6289 // For @link, argument is the URL, not text content
@@ -2563,47 +6294,50 @@ fn validate_tree(
2564 .any(|a| a.key == "aria-label" || a.key == "title")
6295 .any(|a| a.key == "aria-label" || a.key == "title")
2566− diagnostics.push(Diagnostic {
6297+ diagnostics.push(Diagnostic::new(
2567− line: elem.line_num,
6298+ code::MISSING_LINK_TEXT,
2568− column: None,
6299+ Severity::Warning,
2569− message: "@link has no visible text or aria-label (accessibility)"
6300+ elem.line_num,
2570− .to_string(),
6301+ "@link has no visible text or aria-label (accessibility)".to_string(),
2571− severity: Severity::Warning,
6302+ ));
2577− // Contrast ratio check for hex color pairs
6306+ // Contrast ratio check for hex color pairs, each pair on the
2578− {
6307+ // same elements: the element's own, or those an element prefix
2579− let bg_color = elem
6308+ // (`@td:`) picks out inside it
2580− .attrs
6309+ let inside = |key: &str| {
2581− .iter()
6310+ crate::vocab::split_prefixes(key)
2582− .find(|a| crate::vocab::base_attribute(&a.key) == "background")
6311+ .0
2583− .and_then(|a| a.value.as_deref());
6312+ .into_iter()
2584− let fg_color = elem
6313+ .find_map(crate::vocab::element_prefix)
2585− .attrs
6314+ .map(str::to_string)
2587− .find(|a| crate::vocab::base_attribute(&a.key) == "color")
6316+ let mut targets: Vec<Option<String>> = Vec::new();
2588− .and_then(|a| a.value.as_deref());
6317+ for attr in elem.attrs.iter().filter(|a| !a.html) {
6318+ let target = inside(&attr.key);
6319+ if !targets.contains(&target) {
6320+ targets.push(target);
6323+ for target in targets {
6324+ let color = |property: &str| {
6327+ .filter(|a| !a.html && inside(&a.key) == target)
6328+ .find(|a| crate::vocab::base_attribute(&a.key) == property)
6329+ .and_then(|a| a.value.as_deref())
6331+ let (bg_color, fg_color) = (color("background"), color("color"));
2589 if let (Some(bg), Some(fg)) = (bg_color, fg_color)
6332 if let (Some(bg), Some(fg)) = (bg_color, fg_color)
2590− && let (Some(bg_rgb), Some(fg_rgb)) = (
6333+ && let (Some(bg_rgb), Some(fg_rgb)) = (parse_hex_rgb(bg), parse_hex_rgb(fg))
2591− crate::expr::parse_hex_rgb(bg),
2592− crate::expr::parse_hex_rgb(fg),
2595 let ratio = contrast_ratio(bg_rgb, fg_rgb);
6335 let ratio = contrast_ratio(bg_rgb, fg_rgb);
2596 if ratio < 4.5 {
6336 if ratio < 4.5 {
2597− diagnostics.push(Diagnostic {
6337+ diagnostics.push(Diagnostic::new(code::LOW_CONTRAST, Severity::Warning, elem.line_num, format!(
2598− line: elem.line_num,
2601 "low contrast ratio {:.1}:1 between '{}' and '{}' (WCAG AA requires 4.5:1)",
6338 "low contrast ratio {:.1}:1 between '{}' and '{}' (WCAG AA requires 4.5:1)",
2602 ratio, fg, bg
6339 ratio, fg, bg
2604− severity: Severity::Warning,
@@ -2618,43 +6352,34 @@ fn validate_tree(
2618 let has_title = elem.attrs.iter().any(|a| a.key == "title");
6352 let has_title = elem.attrs.iter().any(|a| a.key == "title");
2619 let in_label = parent_kind.is_some_and(|k| k.is_tag("label"));
6353 let in_label = parent_kind.is_some_and(|k| k.is_tag("label"));
2620 if !has_id && !has_aria_label && !has_title && !in_label {
6354 if !has_id && !has_aria_label && !has_title && !in_label {
2621− diagnostics.push(Diagnostic {
6355+ diagnostics.push(Diagnostic::new(code::MISSING_LABEL, Severity::Warning, elem.line_num, format!(
2622− line: elem.line_num,
2625 "{} should have an 'id' (with matching @label[for]), 'aria-label', or be wrapped in @label (accessibility)",
6356 "{} should have an 'id' (with matching @label[for]), 'aria-label', or be wrapped in @label (accessibility)",
2626 element_kind_name(&elem.kind)
6357 element_kind_name(&elem.kind)
2628− severity: Severity::Warning,
2634 // @iframe should have title attribute
6362 // @iframe should have title attribute
2635 if elem.kind.is_tag("iframe") && !elem.attrs.iter().any(|a| a.key == "title") {
6363 if elem.kind.is_tag("iframe") && !elem.attrs.iter().any(|a| a.key == "title") {
2636− diagnostics.push(Diagnostic {
6364+ diagnostics.push(Diagnostic::new(
2637− line: elem.line_num,
6365+ code::MISSING_TITLE,
2638− column: None,
6366+ Severity::Warning,
2639− message: "@iframe missing 'title' attribute (accessibility)".to_string(),
6367+ elem.line_num,
2640− severity: Severity::Warning,
6368+ "@iframe missing 'title' attribute (accessibility)".to_string(),
2641− source_line: None,
6369+ ));
2645 // @button should have accessible text
6372 // @button should have accessible text
2646 if elem.kind.is_tag("button") {
6373 if elem.kind.is_tag("button") {
2647− let has_text = elem.argument.is_some() || !elem.children.is_empty();
6374+ let has_text = !elem.children.is_empty();
2648 let has_aria = elem.attrs.iter().any(|a| a.key == "aria-label");
6375 let has_aria = elem.attrs.iter().any(|a| a.key == "aria-label");
2649 if !has_text && !has_aria {
6376 if !has_text && !has_aria {
2650− diagnostics.push(Diagnostic {
6377+ diagnostics.push(Diagnostic::new(
2651− line: elem.line_num,
6378+ code::MISSING_BUTTON_TEXT,
2652− column: None,
6379+ Severity::Warning,
2653− message: "@button has no text content or aria-label (accessibility)"
6380+ elem.line_num,
2654− .to_string(),
6381+ "@button has no text content or aria-label (accessibility)".to_string(),
2655− severity: Severity::Warning,
6382+ ));
@@ -2667,16 +6392,15 @@ fn validate_tree(
2667 let has_track = elem
6392 let has_track = elem
2668 .children
6393 .children
2670− .any(|c| matches!(c, Node::Element(e) if e.kind.is_tag("source")));
6395+ .any(|c| matches!(c, Node::Element(e) if e.kind.is_tag("track")));
2671 if !has_aria && !has_track {
6396 if !has_aria && !has_track {
2672− diagnostics.push(Diagnostic {
6397+ diagnostics.push(Diagnostic::new(
2673− line: elem.line_num,
6398+ code::MISSING_CAPTIONS,
2674− column: None,
6399+ Severity::Warning,
2675− message: "@video should have aria-label or captions for accessibility"
6400+ elem.line_num,
6401+ "@video should have aria-label or a captions @track for accessibility"
2676 .to_string(),
6402 .to_string(),
2677− severity: Severity::Warning,
6403+ ));
@@ -2686,20 +6410,204 @@ fn validate_tree(
2686 && let Ok(n) = val.parse::<i32>()
6410 && let Ok(n) = val.parse::<i32>()
2687 && n > 0
6411 && n > 0
2689− diagnostics.push(Diagnostic {
6413+ diagnostics.push(Diagnostic::new(code::POSITIVE_TABINDEX, Severity::Warning, elem.line_num, format!("tabindex {} is positive — avoid positive tabindex values as they disrupt natural tab order", n)));
2690− line: elem.line_num,
2692− message: format!("tabindex {} is positive — avoid positive tabindex values as they disrupt natural tab order", n),
2693− severity: Severity::Warning,
6415+ in_function_body(elem, &mut diagnostics[start..]);
6417+ // An element that ends the <p> takes what is inside it out of
6418+ // the paragraph too, so only it is reported
6419+ let in_paragraph = elem.kind == ElementKind::Paragraph
6421+ && ends_a_paragraph(&elem.kind).is_none()
6422+ && !elem.kind.is_tag("button"));
6423+ validate_tree(&elem.children, Some(&elem.kind), in_paragraph, diagnostics);
6428+/// What an element has no place for in HTML, which would otherwise be
6429+/// left out of the page: attributes on `@fragment` (which has no element
6430+/// of its own), styles on `@script` (which isn't shown), a body under a
6431+/// `@script` that has a src (which the browser doesn't run), an element
6432+/// under a `@script` (whose body is code), and content in a void element
6433+/// such as `@input`.
6434+fn dropped_by_the_element(elem: &Element, diagnostics: &mut Vec<Diagnostic>) {
6435+ let name = elem.kind.name();
6436+ let keys = |attrs: Vec<&Attribute>| {
6439+ .map(|a| format!("'{}'", a.key))
6440+ .collect::<Vec<_>>()
6443+ let mut error = |code: &'static str, message: String| {
6444+ diagnostics.push(Diagnostic::error(code, elem.line_num, message).subject(name))
6446+ if elem.kind == ElementKind::Fragment && !elem.attrs.is_empty() {
6448+ code::UNEXPECTED_ARGUMENT,
6450+ "@fragment has no element of its own to put attributes on, so {} would go \
6451+ nowhere: put them on its children, or use @el",
6452+ keys(elem.attrs.iter().collect())
6456+ // The leading argument given twice: an attribute passed to the root
6457+ // of a function whose body gives the argument (written on one line,
6458+ // it is reported where it is read, and the attribute wins there)
6459+ if let Some(argument) = &elem.argument
6460+ && let Some(attr) = elem
6463+ .find(|a| a.html && elem.kind.arg().attributes().contains(&a.key.as_str()))
6466+ code::DUPLICATE_ATTRIBUTE,
6468+ "@{} takes '{}' as its {}, and it also has {}={}: give it once",
6471+ leading_name(&elem.kind),
6473+ attr.value.as_deref().unwrap_or("")
6477+ if elem.kind.is_verbatim() {
6478+ let styles: Vec<&Attribute> = elem
6481+ .filter(|a| !a.html && !crate::vocab::BOOLEAN_HTML_ATTRS.contains(&a.key.as_str()))
6483+ if !styles.is_empty() {
6485+ code::UNEXPECTED_ARGUMENT,
6487+ "@{} isn't shown on the page, so its styles {} would go nowhere",
6493+ let src = elem.argument.clone().or_else(|| {
6496+ .find(|a| a.html && a.key == "src")
6497+ .map(|a| a.value.clone().unwrap_or_default())
6499+ if let Some(src) = src
6500+ && !elem.children.is_empty()
6503+ code::UNEXPECTED_CONTENT,
6505+ "@{0} has both a src ('{1}') and a body: the browser runs only the file, \
6506+ so the body would go nowhere. Put the code in {1}, or leave out the src",
6510+ } else if let Some(Node::Element(child)) = elem
6513+ .find(|child| matches!(child, Node::Element(_)))
6515+ // `@script > @b x`: its body is code, not elements
6517+ code::UNEXPECTED_CONTENT,
6519+ "@{} holds its code as the lines under it, kept as written, so @{} would \
6527+ if elem.kind != ElementKind::Image && elem.attrs.iter().any(|a| !a.html && a.key == "inline") {
6529+ code::UNEXPECTED_ARGUMENT,
6531+ "`inline` puts an image's file into the page, and @{} has none: it only \
6537+ if elem.kind.layout() == Layout::Void && !elem.children.is_empty() {
6539+ code::UNEXPECTED_CONTENT,
6541+ "@{} takes no content: it is an element without a closing tag, so its text \
6542+ and indented lines would go nowhere",
6549+/// `@fragment`, `@script`, `@children` and `@slot`, whose attributes are
6550+/// reported on their own (see `dropped_by_the_element`).
6551+fn has_no_element(kind: &ElementKind) -> bool {
6554+ ElementKind::Fragment | ElementKind::Children | ElementKind::Slot(_)
6555+ ) || kind.is_verbatim()
2698− validate_tree(&elem.children, Some(&elem.kind), diagnostics);
6558+/// htmlang's word `word` for laying out children (`spacing`, `wrap`,
6559+/// `grid-cols`, `grid-rows`) on an element that doesn't lay out its
6560+/// children: an error, and the word is left out.
6561+fn not_a_container(kind: &ElementKind, line: usize, word: &str) -> Diagnostic {
6562+ let name = element_kind_name(kind);
6563+ let (what, instead) = match kind.layout() {
6565+ "is text, whose lines and children flow together with no gap between them",
6566+ "; to space the children out, put them in an @el or @row",
6568+ Layout::Void => ("has no content to lay out", ""),
6570+ "keeps HTML's own layout",
6571+ "; for a flex layout of your own, write CSS, such as `display flex, gap 8`",
6578+ "'{0}' can't go on {1}: {1} {2}. `{0}` works on a row, column or grid \
6579+ (@el, @row, @grid, @section, ...){3}",
6580+ word, name, what, instead
6586+/// Diagnostics about an element a function's body wrote are reported at
6587+/// the call (see `belongs_to_call`); say which body the element is in.
6588+fn in_function_body(elem: &Element, diagnostics: &mut [Diagnostic]) {
6589+ if let Some(function) = &elem.function {
6590+ for d in diagnostics {
6591+ d.message = format!("{}\n in the body of @{}", d.message, function);
6596+/// Report each diagnostic once: a line that runs many times (in a loop, in
6597+/// a function called from one place many times) reports its problems once.
6598+fn dedupe(diagnostics: &mut Vec<Diagnostic>) {
6599+ let mut seen = HashSet::new();
6600+ diagnostics.retain(|d| {
2703fn relative_luminance(r: u8, g: u8, b: u8) -> f64 {
6611fn relative_luminance(r: u8, g: u8, b: u8) -> f64 {
2704 fn linearize(c: u8) -> f64 {
6612 fn linearize(c: u8) -> f64 {
2705 let s = c as f64 / 255.0;
6613 let s = c as f64 / 255.0;
@@ -2712,6 +6620,24 @@ fn relative_luminance(r: u8, g: u8, b: u8) -> f64 {
2712 0.2126 * linearize(r) + 0.7152 * linearize(g) + 0.0722 * linearize(b)
6620 0.2126 * linearize(r) + 0.7152 * linearize(g) + 0.0722 * linearize(b)
6623+/// The red, green and blue of a `#rgb` or `#rrggbb` colour.
6624+fn parse_hex_rgb(s: &str) -> Option<(u8, u8, u8)> {
6625+ let s = s.strip_prefix('#')?;
6626+ if !s.bytes().all(|b| b.is_ascii_hexdigit()) {
6629+ let channel = |i: usize, len: usize| u8::from_str_radix(&s[i..i + len], 16).ok();
6632+ channel(0, 1)? * 17,
6633+ channel(1, 1)? * 17,
6634+ channel(2, 1)? * 17,
6636+ 6 => Some((channel(0, 2)?, channel(2, 2)?, channel(4, 2)?)),
2715fn contrast_ratio(c1: (u8, u8, u8), c2: (u8, u8, u8)) -> f64 {
6641fn contrast_ratio(c1: (u8, u8, u8), c2: (u8, u8, u8)) -> f64 {
2716 let l1 = relative_luminance(c1.0, c1.1, c1.2);
6642 let l1 = relative_luminance(c1.0, c1.1, c1.2);
2717 let l2 = relative_luminance(c2.0, c2.1, c2.2);
6643 let l2 = relative_luminance(c2.0, c2.1, c2.2);
@@ -2719,70 +6645,48 @@ fn contrast_ratio(c1: (u8, u8, u8), c2: (u8, u8, u8)) -> f64 {
2719 (lighter + 0.05) / (darker + 0.05)
6645 (lighter + 0.05) / (darker + 0.05)
2722−// ---------------------------------------------------------------------------
2723−// Variable substitution
2724−// ---------------------------------------------------------------------------
2726−/// Interpolate `$name` variables and `${expr}` expressions into text.
2727−/// Undefined variables, and expressions that don't evaluate, are left as
2728−/// written so they show up in the output.
2729−fn substitute_vars(input: &str, vars: &HashMap<String, String>) -> String {
2730− if !input.contains('$') {
2731− return input.to_string();
2733− let is_name_char = |c: char| c.is_alphanumeric() || matches!(c, '_' | '-' | '.');
2734− let mut result = String::with_capacity(input.len());
2735− let mut rest = input;
2736− while let Some(pos) = rest.find('$') {
2737− result.push_str(&rest[..pos]);
2738− let after = &rest[pos + 1..];
2739− if after.starts_with('{')
2740− && let Some(close) = matching_brace(after)
2742− let source = &after[1..close];
2743− match crate::expr::eval(source, &|name: &str| lookup(vars, name)) {
2744− Ok(value) => result.push_str(&value.to_string()),
2745− Err(_) => result.push_str(&rest[pos..pos + 1 + close + 1]),
2747− rest = &after[close + 1..];
2750− let mut end = after
2751− .find(|c: char| !is_name_char(c))
2752− .unwrap_or(after.len());
2753− while end > 0 && after[..end].ends_with('.') {
2756− let name = &after[..end];
2757− match vars.get(name) {
2758− Some(value) if !name.is_empty() => result.push_str(value),
2761− result.push_str(name);
2764− rest = &after[end..];
2766− result.push_str(rest);
2770/// `@image [inline] icon.svg` becomes the SVG's markup, with `width`,
6648/// `@image [inline] icon.svg` becomes the SVG's markup, with `width`,
2771−/// `height`, `color` / `fill`, `class=` and `id=` applied to the `<svg>`
6649+/// `height`, `color` / `fill` and the HTML attributes (`class=`, `id=`,
2772−/// tag. Other nodes are returned unchanged.
6650+/// `aria-label=`, ...) applied to the `<svg>` tag; any other attribute is
6651+/// an error. Other nodes are returned unchanged.
2773fn inline_svg(node: Node, line_num: usize, ctx: &mut ParseContext) -> Node {
6652fn inline_svg(node: Node, line_num: usize, ctx: &mut ParseContext) -> Node {
2774 let Node::Element(elem) = &node else {
6653 let Node::Element(elem) = &node else {
2775 return node;
6654 return node;
2777− let is_inline_svg = elem.kind == ElementKind::Image
6656+ let inline = elem.kind == ElementKind::Image
2778 && elem.attrs.iter().any(|a| a.key == "inline" && !a.html)
6657 && elem.attrs.iter().any(|a| a.key == "inline" && !a.html)
2779− && elem
6658+ && elem.argument.as_deref().is_some_and(|src| !src.is_empty());
2780− .argument
6659+ if !inline {
2782− .is_some_and(|src| src.ends_with(".svg"));
2783− if !is_inline_svg {
2784 return node;
6660 return node;
6662+ // A raster image: its file, read relative to this one, as a `data:` URI
6666+ .is_some_and(|src| src.ends_with(".svg"))
6668+ let Node::Element(mut elem) = node else {
6671+ let filename = elem.argument.clone().unwrap_or_default();
6672+ let resolved = ctx.resolve(&filename);
6673+ match std::fs::read(&resolved) {
6675+ elem.argument = Some(crate::codegen::data_uri(&filename, &data));
6676+ ctx.included_files.push(resolved);
6678+ Err(e) => ctx.diagnostics.push(Diagnostic::new(
6679+ code::UNREADABLE_FILE,
6683+ "cannot load image '{}' to put it into the page: {}",
6688+ return Node::Element(elem);
2786 let filename = elem.argument.clone().unwrap_or_default();
6690 let filename = elem.argument.clone().unwrap_or_default();
2787 let resolved = match &ctx.base_path {
6691 let resolved = match &ctx.base_path {
2788 Some(base) => base.join(&filename),
6692 Some(base) => base.join(&filename),
@@ -2791,81 +6695,104 @@ fn inline_svg(node: Node, line_num: usize, ctx: &mut ParseContext) -> Node {
2791 let mut svg = match std::fs::read_to_string(&resolved) {
6695 let mut svg = match std::fs::read_to_string(&resolved) {
2792 Ok(text) => text.trim().to_string(),
6696 Ok(text) => text.trim().to_string(),
2793 Err(e) => {
6697 Err(e) => {
2794− ctx.diagnostics.push(Diagnostic {
6698+ ctx.diagnostics.push(Diagnostic::new(
2795− line: line_num,
6699+ code::UNREADABLE_FILE,
2796− column: None,
6700+ Severity::Error,
2797− message: format!("cannot load SVG '{}': {}", filename, e),
6701+ line_num,
2798− severity: Severity::Error,
6702+ format!("cannot load SVG '{}': {}", filename, e),
2799− source_line: None,
6703+ ));
2801 return node;
6704 return node;
2804 ctx.included_files.push(resolved);
6707 ctx.included_files.push(resolved);
6708+ // The file's markup has no class of its own, so a style reaches it only
6709+ // as one of the root's attributes: anything else is reported, never
6710+ // left out silently
6711+ let mut left_out: Vec<String> = Vec::new();
6712+ // The styles go in the root's `style=`, where a length takes its unit
6713+ // and `var(--name)` works, as in any CSS
6714+ let mut style: Vec<String> = Vec::new();
2805 for attr in &elem.attrs {
6715 for attr in &elem.attrs {
2806− let Some(value) = &attr.value else { continue };
6716+ let target = match (attr.key.as_str(), attr.html, &attr.value) {
2807− let target = match (attr.key.as_str(), attr.html) {
6717+ ("inline", false, None) | ("src", true, _) => continue,
2808− ("width", false) | ("height", false) => attr.key.as_str(),
6718+ // `fill` and `shrink` are layout words, which need a class
2809− ("color", false) | ("fill", false) => "fill",
6719+ ("width" | "height", false, Some(value))
2810− ("class", true) | ("id", true) => attr.key.as_str(),
6720+ if matches!(value.as_str(), "fill" | "shrink") =>
2811− _ => continue,
6721+ {
6722+ left_out.push(format!("{} {}", attr.key, value));
6725+ ("width" | "height", false, Some(value)) => {
6726+ let value = crate::vocab::with_px(&attr.key, value);
6727+ style.push(format!("{}:{}", attr.key, value));
6730+ ("color" | "fill", false, Some(value)) => {
6731+ style.push(format!("fill:{}", value));
6734+ ("style", true, Some(value)) => {
6735+ style.insert(0, value.trim().trim_end_matches(';').to_string());
6738+ ("alt", true, _) => {
6739+ left_out.push("alt".to_string());
6742+ (key, true, Some(_)) => key,
6743+ (key, false, None) if crate::vocab::BOOLEAN_HTML_ATTRS.contains(&key) => key,
6745+ left_out.push(attr.key.clone());
2813− svg = set_svg_attr(&svg, target, value);
6749+ let value = attr.value.as_deref().unwrap_or("");
6750+ svg = set_svg_attr(&svg, target, &html_escape_md(value));
2815− Node::Raw(svg)
6752+ if !style.is_empty() {
2816−}
6753+ // After the file's own `style=`, which stays: these come later, so
2817−
6754+ // they win where both set a property
2818−/// Index of the `}` matching the `{` that `s` starts with (skipping
6755+ let mut value = html_escape_md(&style.join(";"));
2819−/// braces inside string literals).
6756+ if let Some(own) = svg_attr_value(&svg, "style")
2820−fn matching_brace(s: &str) -> Option<usize> {
6757+ .map(|range| svg[range].trim().trim_end_matches(';').to_string())
2821− let mut depth = 0;
6758+ .filter(|own| !own.is_empty())
2822− let mut in_string = false;
6759+ {
2823− for (i, c) in s.char_indices() {
6760+ value = format!("{};{}", own, value);
2825− '"' => in_string = !in_string,
2826− _ if in_string => {}
6762+ svg = set_svg_attr(&svg, "style", &value);
2837− None
6764+ if !left_out.is_empty() {
6765+ let alt = left_out.iter().any(|name| name == "alt");
6766+ let names = left_out
6768+ .map(|name| format!("'{}'", name))
6769+ .collect::<Vec<_>>()
6771+ let mut message = format!(
6772+ "{} can't go on an inline SVG: `@image [inline]` puts the file's own markup into the page, which takes `width` and `height` as lengths, `color` or `fill` (as its fill) and HTML attributes (`class=`, `aria-label=`, ...)",
6776+ message.push_str("; an SVG has no alt text: name it with `aria-label=` and `role=img`");
6778+ ctx.diagnostics.push(Diagnostic::new(
6779+ code::UNEXPECTED_ARGUMENT,
2840// ---------------------------------------------------------------------------
6788// ---------------------------------------------------------------------------
2841// Variable usage tracking
6789// Variable usage tracking
2842// ---------------------------------------------------------------------------
6790// ---------------------------------------------------------------------------
2844−/// Scan a string for $name references and record them in the used set.
6792+/// Record the names a string refers to (by syntax) as used.
2845fn track_var_refs(input: &str, used: &mut HashSet<String>) {
6793fn track_var_refs(input: &str, used: &mut HashSet<String>) {
2846− if !input.contains('$') {
6794+ if input.contains('$') {
2847− return;
6795+ used.extend(interp::names(input).into_iter().map(String::from));
2849− let chars: Vec<char> = input.chars().collect();
2851− while i < chars.len() {
2853− && i + 1 < chars.len()
2854− && (chars[i + 1].is_alphanumeric() || chars[i + 1] == '_' || chars[i + 1] == '-')
2857− let mut end = start;
2858− while end < chars.len()
2859− && (chars[end].is_alphanumeric() || chars[end] == '-' || chars[end] == '_')
2863− let name: String = chars[start..end].iter().collect();
@@ -2873,49 +6800,63 @@ fn track_var_refs(input: &str, used: &mut HashSet<String>) {
2873// Unused definition warnings
6800// Unused definition warnings
2874// ---------------------------------------------------------------------------
6801// ---------------------------------------------------------------------------
2876−fn check_unused(ctx: &mut ParseContext) {
6803+/// Warn about definitions nothing uses, except `exported` ones (the
6804+/// definitions of a library, for the files that include it).
6805+fn check_unused(ctx: &mut ParseContext, exported: &HashSet<String>) {
2877 // Check unused @let variables
6806 // Check unused @let variables
2878 for (name, &line) in &ctx.let_lines {
6807 for (name, &line) in &ctx.let_lines {
2879− if name.starts_with("--") {
6808+ if exported.contains(name) {
2880− continue; // CSS vars are always used
6809+ // A library's names are for other files (a custom property
6810+ // isn't a variable, so it is never listed here)
2882 if !ctx.used_variables.contains(name) {
6813 if !ctx.used_variables.contains(name) {
2883− ctx.diagnostics.push(Diagnostic {
6814+ ctx.diagnostics.push(
2884− line,
6815+ Diagnostic::new(
2885− column: None,
6816+ code::UNUSED_VARIABLE,
2886− message: format!("unused variable '${}' (defined but never referenced)", name),
6817+ Severity::Warning,
2887− severity: Severity::Warning,
6818+ line,
2888− source_line: None,
6819+ format!("unused variable '${}' (defined but never referenced)", name),
6821+ .subject(name.as_str()),
2893− // Check unused attribute bundles (@let name [...])
6826+ // Check unused attribute bundles (@let name [...]). A `$name` in code
6827+ // that doesn't run (an `if()` branch or `@if` not taken) counts too.
2894 for (name, &line) in &ctx.define_lines {
6828 for (name, &line) in &ctx.define_lines {
2895− if !ctx.used_defines.contains(name) {
6829+ if !ctx.used_defines.contains(name)
2896− ctx.diagnostics.push(Diagnostic {
6830+ && !ctx.used_variables.contains(name)
2897− line,
6831+ && !exported.contains(name)
2898− column: None,
6832+ {
2899− message: format!(
6833+ ctx.diagnostics.push(
2900− "unused attribute bundle '${}' (defined but never referenced)",
6834+ Diagnostic::new(
2901− name
6835+ code::UNUSED_BUNDLE,
2902− ),
6836+ Severity::Warning,
2903− severity: Severity::Warning,
6837+ line,
2904− source_line: None,
6838+ format!(
2905− });
6839+ "unused attribute bundle '${}' (defined but never referenced)",
6843+ .subject(name.as_str()),
2909 // Check unused functions (@let name ... with body)
6848 // Check unused functions (@let name ... with body)
2910 for (name, &line) in &ctx.fn_lines {
6849 for (name, &line) in &ctx.fn_lines {
2911− if !ctx.used_functions.contains(name) {
6850+ if !ctx.used_functions.contains(name) && !exported.contains(name) {
2912− ctx.diagnostics.push(Diagnostic {
6851+ ctx.diagnostics.push(
2913− line,
6852+ Diagnostic::new(
2914− column: None,
6853+ code::UNUSED_FUNCTION,
2915− message: format!("unused function '@{}' (defined but never called)", name),
6854+ Severity::Warning,
2916− severity: Severity::Warning,
6855+ line,
2917− source_line: None,
6856+ format!("unused function '@{}' (defined but never called)", name),
6858+ .subject(name.as_str()),
@@ -3001,34 +6942,6 @@ fn parse_json_with_error(input: &str) -> Result<JsonValue, String> {
3004−/// Visit the lines of a block in source order, children after their line.
3005−fn for_each_line<'a>(block: &'a [Syntax], f: &mut impl FnMut(&'a Syntax)) {
3006− for node in block {
3008− if let Syntax::Line { children, .. } = node {
3009− for_each_line(children, f);
3014−/// The text of a block whose lines are content, not htmlang (`@head`,
3015−/// `@style`, `@markdown`): each line trimmed, verbatim text as is.
3016−fn block_text(block: &[Syntax]) -> String {
3017− let mut text = String::new();
3018− for_each_line(block, &mut |node| match node {
3019− Syntax::Line { text: line, .. } => {
3020− text.push_str(line.trim());
3023− Syntax::Raw { text: raw, .. } => {
3024− text.push_str(raw);
3032fn parse_json_value(chars: &[char], mut pos: usize) -> Option<(JsonValue, usize)> {
6945fn parse_json_value(chars: &[char], mut pos: usize) -> Option<(JsonValue, usize)> {
3033 pos = skip_ws(chars, pos);
6946 pos = skip_ws(chars, pos);
3034 if pos >= chars.len() {
6947 if pos >= chars.len() {
@@ -3209,75 +7122,21 @@ fn skip_ws(chars: &[char], mut pos: usize) -> usize {
3212−/// Flatten a JSON value into variable assignments.
7125+/// A JSON value as an htmlang value: an object is a record, an array a
3213−/// - Top-level object: each key becomes `prefix.key`
7126+/// list, a string text (never quoted text), `null` empty. A number keeps
3214−/// - Top-level array: `prefix` becomes comma-separated, `prefix._count` set
7127+/// the text it is written with (`1.50`), and reads as a number.
3215−/// - Array of objects: each item becomes space-separated values for @each destructuring
7128+fn json_value(json: JsonValue) -> Value {
3216−fn flatten_json(prefix: &str, value: &JsonValue, vars: &mut HashMap<String, String>) {
7129+ match json {
3217− match value {
7130+ JsonValue::Null => Value::empty(),
3218− JsonValue::Str(s) => {
7131+ JsonValue::Bool(b) => Value::Bool(b),
3219− vars.insert(prefix.to_string(), s.clone());
7132+ JsonValue::Number(n) | JsonValue::Str(n) => Value::Str(n),
3220− }
7133+ JsonValue::Array(items) => Value::list(items.into_iter().map(json_value).collect()),
3221− JsonValue::Number(n) => {
7134+ JsonValue::Object(pairs) => Value::Record(Rc::new(
3222− vars.insert(prefix.to_string(), n.clone());
7135+ pairs
3223− }
7136+ .into_iter()
3224− JsonValue::Bool(b) => {
7137+ .map(|(key, value)| (key, json_value(value)))
3225− vars.insert(prefix.to_string(), b.to_string());
3227− JsonValue::Null => {
3228− vars.insert(prefix.to_string(), String::new());
3230− JsonValue::Object(pairs) => {
3231− for (key, val) in pairs {
3232− flatten_json(&format!("{}.{}", prefix, key), val, vars);
3235− JsonValue::Array(items) => {
3236− // A list: its length under `NAME#` (see `lookup`), its text
3237− // items joined as its value, and each item as `NAME.INDEX`
3238− vars.insert(format!("{}#", prefix), items.len().to_string());
3239− let text: Vec<String> = items
3241− .map(json_value_to_string)
3242− .filter(|s| !s.is_empty())
3244− vars.insert(prefix.to_string(), text.join(", "));
3245− // Also set indexed access: prefix.0, prefix.1, etc.
3246− for (i, item) in items.iter().enumerate() {
3247− flatten_json(&format!("{}.{}", prefix, i), item, vars);
3253−/// Resolve `$name` for an expression: a list if `name` was loaded from a
3254−/// JSON array, else its text.
3255−fn lookup(vars: &HashMap<String, String>, name: &str) -> Option<crate::expr::Value> {
3256− use crate::expr::Value;
3258− .get(&format!("{}#", name))
3259− .and_then(|n| n.parse::<usize>().ok())
3261− Some(len) => Some(Value::List(
3264− vars.get(&format!("{}.{}", name, i))
3266− .unwrap_or_default()
3268 .collect(),
7138 .collect(),
3270− None => vars.get(name).cloned().map(Value::Str),
3274−fn json_value_to_string(v: &JsonValue) -> String {
3276− JsonValue::Str(s) => s.clone(),
3277− JsonValue::Number(n) => n.clone(),
3278− JsonValue::Bool(b) => b.to_string(),
3279− JsonValue::Null => String::new(),
3280− JsonValue::Array(_) | JsonValue::Object(_) => String::new(),
@@ -3285,6 +7144,29 @@ fn json_value_to_string(v: &JsonValue) -> String {
3285// SVG attribute injection helper
7144// SVG attribute injection helper
3286// ---------------------------------------------------------------------------
7145// ---------------------------------------------------------------------------
7147+/// Where the root `<svg ...>` tag's `attr_name="..."` value is, as a byte
7148+/// range of `svg`. Only the opening tag is read, so a child's attribute is
7149+/// never found, and the name must follow whitespace, so `width` doesn't
7150+/// match `stroke-width`.
7151+fn svg_attr_value(svg: &str, attr_name: &str) -> Option<std::ops::Range<usize>> {
7152+ let tag_start = svg.find("<svg")?;
7153+ let tag_end = svg[tag_start..]
7155+ .map(|p| tag_start + p)
7156+ .unwrap_or(svg.len());
7157+ let tag = &svg[tag_start..tag_end];
7158+ let pattern = format!("{}=\"", attr_name);
7159+ let (pos, _) = tag.match_indices(&pattern).find(|(pos, _)| {
7163+ .is_some_and(char::is_whitespace)
7165+ let value_start = tag_start + pos + pattern.len();
7166+ let end = svg[value_start..tag_end].find('"')?;
7167+ Some(value_start..value_start + end)
3288fn set_svg_attr(svg: &str, attr_name: &str, value: &str) -> String {
7170fn set_svg_attr(svg: &str, attr_name: &str, value: &str) -> String {
3289 // Only the opening <svg ...> tag is touched, so child attributes such as
7171 // Only the opening <svg ...> tag is touched, so child attributes such as
3290 // `stroke-width` are left alone.
7172 // `stroke-width` are left alone.
@@ -3295,26 +7177,14 @@ fn set_svg_attr(svg: &str, attr_name: &str, value: &str) -> String {
3295 .find('>')
7177 .find('>')
3296 .map(|p| tag_start + p)
7178 .map(|p| tag_start + p)
3297 .unwrap_or(svg.len());
7179 .unwrap_or(svg.len());
3298− let tag = &svg[tag_start..tag_end];
3300− // Replace an existing attribute (must be preceded by whitespace so that
7181+ // Replace an existing attribute
3301− // `width` doesn't match `stroke-width`).
7182+ if let Some(existing) = svg_attr_value(svg, attr_name) {
3302− let pattern = format!("{}=\"", attr_name);
7183+ let mut result = String::with_capacity(svg.len());
3303− let existing = tag.match_indices(&pattern).find(|(pos, _)| {
7184+ result.push_str(&svg[..existing.start]);
3304− tag[..*pos]
7185+ result.push_str(value);
3305− .chars()
7186+ result.push_str(&svg[existing.end..]);
3306− .next_back()
7187+ return result;
3307− .is_some_and(char::is_whitespace)
3309− if let Some((pos, _)) = existing {
3310− let value_start = tag_start + pos + pattern.len();
3311− if let Some(end) = svg[value_start..tag_end].find('"') {
3312− let mut result = String::with_capacity(svg.len());
3313− result.push_str(&svg[..value_start]);
3314− result.push_str(value);
3315− result.push_str(&svg[value_start + end..]);
3320 // Otherwise inject it into the opening tag (before a self-closing `/`).
7190 // Otherwise inject it into the opening tag (before a self-closing `/`).
@@ -3637,7 +7507,10 @@ mod tests {
3638 fn parses_page_directive() {
7508 fn parses_page_directive() {
3639 let r = parse_ok("@page My Title\n");
7509 let r = parse_ok("@page My Title\n");
3640− assert_eq!(r.document.page_title.as_deref(), Some("My Title"));
7510+ assert_eq!(
7511+ r.document.page.map(|p| p.title).as_deref(),