@@ -1,7651 +0,0 @@
1−use std::collections::{HashMap, HashSet};
2−use std::path::{Path, PathBuf};
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};
12−// ---------------------------------------------------------------------------
14−// ---------------------------------------------------------------------------
16−pub struct ParseResult {
17− pub document: Document,
18− pub diagnostics: Vec<Diagnostic>,
19− pub included_files: Vec<PathBuf>,
22−/// An error that stops one line from being evaluated.
23−type ParseError = Diagnostic;
25−// ---------------------------------------------------------------------------
27−// ---------------------------------------------------------------------------
31− /// The parameters in the order they are declared; one without a
32− /// default is required.
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`: its class (`hl-fn-NAME-HASH`), and the
48− /// stylesheet nested under it, written into the page once the function
49− /// is called (see `Document::scoped_css`).
50− scoped: Option<(String, 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()
169−struct ParseContext {
170− /// Source line currently being parsed, for diagnostics raised deep
171− /// inside helpers that don't take a line number.
172− current_line: usize,
173− /// What the `@page` said, once one has run
175− /// Where that `@page` is, for the error a second one gets
176− page_at: Option<String>,
177− meta_tags: Vec<(String, String)>,
178− head_blocks: Vec<String>,
179− /// The first `@meta` or `@head` that ran, for the warning a file
180− /// without `@page` gets: a fragment has no `<head>` for them.
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>>,
187− css_vars: Vec<(String, String)>,
188− custom_css: Vec<String>,
189− /// The scoped `@style` of each function called so far
190− scoped_css: Vec<String>,
191− og_tags: Vec<(String, String)>,
192− diagnostics: Vec<Diagnostic>,
193− base_path: Option<PathBuf>,
194− included_files: Vec<PathBuf>,
195− include_stack: Vec<PathBuf>,
196− fn_call_stack: Vec<String>,
197− file_cache: HashMap<PathBuf, String>,
198− /// Track which @let variables are referenced (for unused warnings)
199− used_variables: HashSet<String>,
200− /// Track which functions are called (for unused warnings)
201− used_functions: HashSet<String>,
202− /// Track which attribute bundles are referenced (for unused warnings)
203− used_defines: HashSet<String>,
204− /// Line numbers of @let definitions (name -> line)
205− let_lines: HashMap<String, usize>,
206− /// Line numbers of function definitions (name -> line)
207− fn_lines: HashMap<String, usize>,
208− /// Line numbers of attribute bundle definitions (name -> line)
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;
326−/// Evaluates a syntax tree (see `syntax.rs`) into the document's nodes.
330− /// Bind a value to `name` in the innermost block.
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> {
343− track_var_refs(src, &mut self.used_variables);
344− match crate::expr::eval(src, &self.env) {
345− Ok(value) => Some(value),
347− // Without the line to point into, show the expression
348− let shown = matches!(&self.current_source, (current, Some(_)) if *current == line);
349− let before = self.diagnostics.len();
350− self.report(error.at(0), line, column);
351− if !shown && let Some(diagnostic) = self.diagnostics.get_mut(before) {
352− diagnostic.source_line = Some(src.into());
359− /// Evaluate a condition; an invalid one is reported and counts as false.
360− fn condition(&mut self, src: &str, line: usize, column: Option<usize>) -> bool {
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),
757−/// The standard library (`std.hl`): components and bundles defined in
758−/// htmlang itself and available in every file.
759−const PRELUDE: &str = include_str!("std.hl");
761−fn load_prelude(ctx: &mut ParseContext) {
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;
770− // Library definitions aren't the file's own: never report them unused.
771− ctx.fn_lines.clear();
772− ctx.define_lines.clear();
773− ctx.let_lines.clear();
777−pub fn parse(input: &str) -> ParseResult {
778− parse_with_base(input, None)
781−pub fn parse_with_base(input: &str, base_path: Option<&Path>) -> ParseResult {
782− let mut ctx = ParseContext {
786− meta_tags: Vec::new(),
787− head_blocks: Vec::new(),
789− env: Env::default(),
790− defined_functions: HashMap::new(),
791− css_vars: Vec::new(),
792− custom_css: Vec::new(),
793− scoped_css: Vec::new(),
794− og_tags: Vec::new(),
795− diagnostics: Vec::new(),
796− base_path: base_path.map(|p| p.to_path_buf()),
797− included_files: Vec::new(),
798− include_stack: Vec::new(),
799− fn_call_stack: Vec::new(),
800− file_cache: HashMap::new(),
801− used_variables: HashSet::new(),
802− used_functions: HashSet::new(),
803− used_defines: HashSet::new(),
804− let_lines: HashMap::new(),
805− fn_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(),
820− load_prelude(&mut ctx);
821− let tree = ctx.parse_tree(input);
822− ctx.diagnostics.extend(tree.diagnostics.iter().cloned());
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(_) => {}
876− document: Document {
878− meta_tags: ctx.meta_tags,
879− head_blocks: ctx.head_blocks,
882− css_vars: ctx.css_vars,
883− custom_css: ctx.custom_css,
884− scoped_css: ctx.scoped_css,
885− og_tags: ctx.og_tags,
888− diagnostics: ctx.diagnostics,
889− included_files: ctx.included_files,
893−// ---------------------------------------------------------------------------
894−// Code that never runs: an untaken branch, an uncalled function, a loop over
896−// ---------------------------------------------------------------------------
898−/// Collect the functions defined anywhere in `nodes` and in the files they
899−/// include (by a literal path), into `ctx.namespace`.
900−fn collect_namespace(
901− nodes: &[syntax::Node],
902− base: Option<PathBuf>,
903− seen: &mut HashSet<PathBuf>,
904− ctx: &mut ParseContext,
906− let mut includes = Vec::new();
908− node.walk(&mut |node| match node.directive().map(|d| &d.args) {
909− Some(DirectiveArgs::Let(def)) if matches!(def.form, LetForm::Function(_)) => {
910− ctx.namespace.insert(def.name.clone());
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('$') {
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);
939−/// Check the lines that were never evaluated: element and function names,
940−/// and the attributes of built-in elements (those that don't depend on a
941−/// variable). Names that come from data are only checked when evaluated.
942−fn check_unevaluated(ctx: &mut ParseContext) {
943− let trees = std::mem::take(&mut ctx.trees);
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);
963−fn check_unevaluated_node(node: &syntax::Node, ctx: &mut ParseContext) {
964− if !ctx.visited.contains(&node.id) {
965− let line = node.span.line;
966− // A reference from code that doesn't run still counts as a use
967− track_var_refs(&node.source, &mut ctx.used_variables);
968− let before = ctx.diagnostics.len();
970− NodeKind::Element(element) => {
971− for head in &element.chain {
972− check_head(head, line, ctx);
974− check_unevaluated_content(node, element, ctx);
975− if let Some(text) = &element.text {
976− check_inline_heads(text, line, ctx);
979− NodeKind::Text(text) => check_inline_heads(text, line, ctx),
980− // `@page`'s attributes are checked like an element's (a layout's
981− // `@page` is in a function that may not run in this file)
982− NodeKind::Directive(syntax::Directive {
984− DirectiveArgs::Page {
985− attrs: Some(list), ..
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);
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);
1010−/// Check the content passed to the calls of a line that was never
1011−/// evaluated: its `@slot NAME` blocks, and, for a function without
1012−/// `@children`, any other content.
1013−fn check_unevaluated_content(
1014− node: &syntax::Node,
1015− element: &syntax::ElementLine,
1016− ctx: &mut ParseContext,
1018− let calls: Vec<Option<(String, Rc<FnDef>)>> = element
1022− let function = ctx.defined_functions.get(&head.name)?;
1023− Some((head.name.clone(), function.clone()))
1026− check_fillers(node, element, &calls, ctx);
1027− let last = calls.len() - 1;
1028− for (i, call) in calls.iter().enumerate() {
1029− let Some((name, function)) = call else {
1032− if function.has_children || function.wraps_itself {
1035− let content = if i == last {
1036− element.text.is_some() || holds_content(&node.children, ctx)
1038− element.chain[i + 1].name != "slot" || !slot_is_built_in(ctx)
1041− let head = &element.chain[i];
1042− ctx.push_once(no_children(
1045− name_column(head, node.span.line),
1051−/// Check a head that was never evaluated: its name, and its attributes
1052−/// (for a call, see [`check_call`]).
1053−fn check_head(head: &syntax::Head, line: usize, ctx: &mut ParseContext) {
1055− ctx.namespace.contains(&head.name) || ctx.defined_functions.contains_key(&head.name);
1057− ctx.used_functions.insert(head.name.clone());
1058− if let Some(function) = ctx.defined_functions.get(&head.name).cloned()
1059− && !function.wraps_itself
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));
1094−/// The attributes of a list that is never evaluated that can be checked
1095−/// together: not bundles or `if()`s. Names are checked; a value with a
1096−/// variable in it depends on what the variable holds, so only a literal
1097−/// value is (the other is checked as an empty value).
1098−/// `@page`'s own rules (see `check_page_attr`) for a list that isn't
1099−/// evaluated, as written: a value made from a variable counts as given.
1100−fn check_page_tokens(tokens: &[syntax::Attr], line: usize, ctx: &mut ParseContext) {
1101− for token in tokens {
1102− match &token.choice {
1104− for branch in &choice.branches {
1105− check_page_tokens(branch.attrs(), line, ctx);
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("$"),
1121− Some(token.span.column),
1129−fn literal_attrs(tokens: &[syntax::Attr]) -> Vec<syntax::Attr> {
1130− // A prefixed group is checked with its prefixes, as far as its own
1131− // attributes can be; a prefixed bundle or `if()` depends on what it holds
1132− let group = |a: &syntax::Attr| {
1133− let prefixed = a.prefixed.as_ref()?;
1134− let syntax::Branch::Group { list, trailing } = &prefixed.target else {
1137− let mut list = list.clone();
1138− list.attrs = literal_attrs(&list.attrs);
1139− let mut a = a.clone();
1140− a.prefixed = Some(Box::new(syntax::Prefixed {
1141− target: syntax::Branch::Group {
1143− trailing: trailing.clone(),
1145− ..(**prefixed).clone()
1149− let groups = tokens.iter().filter_map(group);
1153− let bundle = a.key.starts_with('$') && 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);
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));
1195−/// Report each parameter a call's list writes `name=value`, with the value
1196−/// as written and its column; returns their names, so the evaluated call
1197−/// doesn't report them again.
1198−fn written_parameter_forms(
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());
1226−fn check_inline_heads(text: &syntax::Text, line: usize, ctx: &mut ParseContext) {
1227− for segment in &text.segments {
1228− if let Segment::Inline(inline) = segment {
1229− check_head(&inline.head, line, ctx);
1230− if let Some(text) = &inline.text {
1231− check_inline_heads(text, line, ctx);
1237−// ---------------------------------------------------------------------------
1239−// ---------------------------------------------------------------------------
1241−/// The `@else` lines that continue the `@if` or `@each` before `from`, and
1242−/// the position after them.
1243−fn else_branches(block: &[syntax::Node], from: usize, is_if: bool) -> (Vec<&syntax::Node>, usize) {
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);
1270− fn eval_block(&mut self, block: &[syntax::Node], ctx: &mut ParseContext) -> Vec<Node> {
1271− let mut nodes = Vec::new();
1273− while i < block.len() {
1274− let node = &block[i];
1276− if node.is_trivia() {
1279− let result = match node.directive().map(|d| d.name()) {
1280− Some(name @ ("if" | "each")) => {
1281− let (branches, next) = else_branches(block, i, name == "if");
1284− Ok(Some(self.eval_if(node, &branches, ctx)))
1286− self.eval_each(node, branches.first().copied(), ctx)
1289− // Reported as a syntax error
1291− ctx.visited.insert(node.id);
1294− _ => self.eval(node, ctx),
1297− Ok(Some(new_nodes)) => nodes.extend(new_nodes),
1299− // Record the error and go on, to report several in one pass
1302− .get_or_insert_with(|| node.source.as_str().into());
1303− ctx.diagnostics.push(e);
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);
1319− /// `@if` with its `@else if` / `@else` branches. Every condition is
1320− /// checked (and its errors reported); the first that holds picks the
1324− node: &syntax::Node,
1325− branches: &[&syntax::Node],
1326− ctx: &mut ParseContext,
1328− let mut chosen = None;
1329− for branch in std::iter::once(node).chain(branches.iter().copied()) {
1330− ctx.visited.insert(branch.id);
1332− let holds = match branch.directive().map(|d| &d.args) {
1333− Some(DirectiveArgs::Condition(condition))
1334− | Some(DirectiveArgs::Else {
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));
1397− node: &syntax::Node,
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),
1413− if let Some(first) = &ctx.page_at {
1414− let again = if *first == here {
1415− "this @page runs a second time (in a loop, or in a function called \
1419− format!("a second @page (this page already has one, on {})", first)
1421− let diagnostic = Diagnostic::error(
1422− code::DUPLICATE_PAGE,
1425− "{}: a page has one @page, the root element that styles its <body>",
1429− .source(content.clone())
1431− ctx.diagnostics.push(diagnostic);
1433− ctx.page_at = Some(here);
1434− ctx.page = Some(page);
1439− ("let", DirectiveArgs::Let(def)) => {
1440− let name = def.name.as_str();
1441− // Values, bundles and functions share one namespace: a
1442− // definition replaces whatever the name meant in its block
1444− LetForm::Function(function) => {
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()),
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());
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))]));
1550− let filename = ctx.interpolate_text(&file.raw, line_num, Some(file.span.column));
1551− let resolved = ctx.resolve(&filename);
1552− let md_text = match ctx.read_file(&resolved) {
1555− ctx.diagnostics.push(
1557− code::UNREADABLE_FILE,
1559− format!("cannot read markdown '{}': {}", filename, e),
1561− .source(content.clone()),
1566− ctx.included_files.push(resolved);
1567− let md_lines: Vec<String> = md_text.lines().map(|l| l.to_string()).collect();
1568− Ok(Some(vec![Node::Raw(markdown_to_html(&md_lines))]))
1571− ("include", DirectiveArgs::Text(Some(path))) => {
1572− self.eval_include(node.id, path, line_num, content, ctx)
1575− ("data", DirectiveArgs::Data { name, source, .. }) => {
1576− self.eval_data(name, source, line_num, content, ctx);
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())]))
1587− // A header with a syntax error (reported), or a directive
1588− // without its argument
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
1625− let imported_text = match ctx.read_file(&resolved) {
1628− ctx.diagnostics.push(
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);
1677− ctx.base_path = saved_base;
1678− ctx.include_stack.pop();
1679− Ok(Some(included_nodes))
1682− /// @data $name file.json values as $name.key
1683− /// @data $name dir/*.json a list of the files' records
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()));
1722− // Inline JSON: @data $links [{"label": "Home", "url": "/"}]
1723− let (json_text, source) = if filename.starts_with(['[', '{']) {
1724− (filename.to_string(), "the inline data".to_string())
1726− let filename = ctx.interpolate_text(filename, line_num, Some(source.span.column));
1727− if filename.contains('*') {
1728− self.load_data_glob(&prefix, &filename, line_num, content, ctx);
1731− let resolved = ctx.resolve(&filename);
1732− match std::fs::read_to_string(&resolved) {
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),
1763− /// `@data $name dir/*.json`: a list with one record per matching file
1764− /// (in name order), whose `file` is the file's name without extension.
1771− ctx: &mut ParseContext,
1773− let base = ctx.base_path.clone().unwrap_or_else(|| PathBuf::from("."));
1774− let pattern_path = Path::new(pattern);
1775− let dir = match pattern_path.parent() {
1776− Some(dir) if !dir.as_os_str().is_empty() => base.join(dir),
1779− let file_pattern = pattern_path
1781− .unwrap_or_default()
1784− let mut files: Vec<PathBuf> = match std::fs::read_dir(&dir) {
1785− Ok(entries) => entries
1790− .is_some_and(|n| glob_match(&file_pattern, &n.to_string_lossy()))
1794− ctx.diagnostics.push(
1796− code::UNREADABLE_FILE,
1799− format!("cannot read directory for '{}': {}", pattern, e),
1801− .source(content.to_string()),
1807− let mut records = Vec::new();
1808− for file in files {
1811− .unwrap_or_default()
1814− let text = match std::fs::read_to_string(&file) {
1817− ctx.diagnostics.push(
1819− code::UNREADABLE_FILE,
1822− format!("cannot load data '{}': {}", file.display(), e),
1824− .source(content.to_string()),
1829− match parse_json_with_error(&text) {
1830− Ok(JsonValue::Object(mut pairs)) => {
1831− if !pairs.iter().any(|(key, _)| key == "file") {
1832− pairs.push(("file".to_string(), JsonValue::Str(stem)));
1834− records.push(JsonValue::Object(pairs));
1836− Ok(_) => ctx.diagnostics.push(
1838− code::INVALID_JSON,
1841− format!("'{}' should hold a JSON object", file.display()),
1843− .source(content.to_string()),
1845− Err(detail) => ctx.diagnostics.push(
1847− code::INVALID_JSON,
1850− format!("invalid JSON in '{}': {}", file.display(), detail),
1852− .source(content.to_string()),
1855− ctx.included_files.push(file);
1857− ctx.bind(name, json_value(JsonValue::Array(records)));
1860− /// `@each $item in LIST` or `@each $item, $index in LIST`, with the
1861− /// `@else` that follows it. LIST is a value (see
1862− /// [`ParseContext::slot_value`]): a list written with commas, a range,
1863− /// or one `$name` or `${...}` that holds a list. Each item is bound
1864− /// whole to `$item`, and each iteration is a block of its own.
1867− node: &syntax::Node,
1868− empty_branch: Option<&syntax::Node>,
1869− ctx: &mut ParseContext,
1870− ) -> Result<Option<Vec<Node>>, ParseError> {
1871− ctx.visited.insert(node.id);
1872− if let Some(branch) = empty_branch {
1873− ctx.visited.insert(branch.id);
1876− // A malformed header is a syntax error, already reported
1877− let Some(DirectiveArgs::Each(header)) = node.directive().map(|d| &d.args) else {
1880− let body = &node.children;
1881− let empty: &[syntax::Node] = empty_branch.map_or(&[], |b| &b.children);
1882− let (item, index) = (header.item.as_str(), header.index.as_deref());
1883− let list = &header.list;
1884− // `[...]` is an attribute list or JSON elsewhere, not a list here
1885− let bracketed = list.raw.starts_with('[') && list.raw.ends_with(']');
1886− let (source, filled) = match bracketed {
1887− true => (Value::empty(), false),
1888− false => ctx.slot_value(&list.raw, list.span.line, Some(list.span.column)),
1890− let not_a_list = |message: String, ctx: &ParseContext| {
1891− let diagnostic = Diagnostic::error(code::INVALID_LOOP, list.span.line, message)
1892− .column(list.span.column)
1893− .subject(list.raw.as_str());
1894− match &ctx.current_source {
1895− (current, Some(text)) if *current == list.span.line => {
1896− diagnostic.source(text.clone())
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);
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],
1937− if body.iter().all(syntax::Node::is_trivia) {
1938− return Ok(Some(Vec::new()));
1940− if items.is_empty() {
1941− return Ok(Some(self.eval_scoped(empty, ctx)));
1943− let mut nodes = Vec::new();
1944− for (i, value) in items.into_iter().enumerate() {
1946− ctx.bind(item, value);
1947− if let Some(index) = index {
1948− ctx.bind(index, Value::Num(i as f64));
1950− nodes.extend(self.eval_block(body, ctx));
1956− fn define_function(
1959− params: &[syntax::Param],
1960− node: &syntax::Node,
1961− ctx: &mut ParseContext,
1963− let line_num = node.span.line;
1964− let body = &node.children;
1965− // An @style block at the top of the body is scoped to the
1966− // function: its rules apply inside a `.hl-fn-NAME-HASH` wrapper (a
1967− // generated class never has a second `-`, so the two can't meet).
1968− // The hash is the stylesheet's, so two functions of one name with
1969− // two stylesheets, in two files, don't style each other's elements
1970− // in a page that has both. It is written into the page when the
1971− // function is called.
1972− let (style, body): (Vec<&syntax::Node>, Vec<&syntax::Node>) =
1973− body.iter().partition(|node| node.is_directive("style"));
1974− let scoped = (!style.is_empty()).then(|| {
1975− let css: String = style
1978− ctx.visited.insert(node.id);
1979− verbatim_content(node)
1982− let digits = crate::codegen::CLASS_DIGITS;
1983− let hash = crate::codegen::hash_digits(crate::codegen::stable_hash(&css), digits);
1984− let class = format!("hl-fn-{}-{}", name, hash);
1985− // Nested under the scope class, so any CSS works (multi-line
1986− // rules, at-rules)
1987− let css = if css.trim().is_empty() {
1990− format!(".{} {{\n{}}}", class, css)
1995− // A default is filled in only when a call leaves its parameter
1996− // out, so the names in it count as used here
1997− for default in params.iter().filter_map(|p| p.default.as_ref()) {
1998− track_var_refs(default, &mut ctx.used_variables);
2000− ctx.fn_lines.entry(name.to_string()).or_insert(line_num);
2001− let wraps_itself = ElementKind::from_name(name).is_some()
2002− && body.iter().any(|node| calls_unguarded(node, name));
2006− code::RECURSIVE_CALL,
2009− "@{0} in the body of `@let @{0}` calls the function itself, not the \
2010− element @{0}, so it would never stop: give the function another name \
2011− (such as @site-{0})",
2018− for node in &body {
2019− node.walk(&mut |node| {
2020− if let Some(d) = marker_in_text(node) {
2025− let body: Vec<syntax::Node> = body.into_iter().cloned().collect();
2026− let (slots, has_children) = declared_slots(&body, ctx);
2027− let function = Rc::new(FnDef {
2028− params: params.to_vec(),
2030− source: ctx.current_source.1.clone(),
2033− file: ctx.current_file.clone(),
2037− env: ctx.env.clone(),
2040− ctx.defined_functions
2041− .insert(name.to_string(), function.clone());
2042− ctx.env.define(name, Binding::Function(function));
2045− /// An element line: a chain of elements and function calls, the last of
2046− /// which gets the indented children.
2049− node: &syntax::Node,
2050− element: &syntax::ElementLine,
2051− ctx: &mut ParseContext,
2052− ) -> Result<Vec<Node>, ParseError> {
2053− // An unclosed attribute list is a syntax error, already reported
2057− .any(|h| h.attrs.as_ref().is_some_and(|a| !a.closed))
2059− return Ok(Vec::new());
2061− let line_num = node.span.line;
2062− let last = element.chain.len() - 1;
2063− // Each head is read where it is written, left to right. The
2064− // children belong to the last one, so the chain is built right to
2065− // left, each link wrapping the next.
2066− let mut links = Vec::new();
2067− for (i, head) in element.chain.iter().enumerate() {
2068− let text = if i == last {
2069− element.text.as_ref()
2073− links.push(resolve(head, text, line_num, &node.source, ctx)?);
2075− let calls: Vec<Option<(String, Rc<FnDef>)>> = links
2077− .map(|link| match link {
2078− Resolved::Call(call) => Some((call.name.clone(), call.function.clone())),
2079− Resolved::Element(_) => None,
2082− let mut current = self.eval_scoped(&node.children, ctx);
2083− // After the lines under the call ran, so the files they include
2085− check_fillers(node, element, &calls, ctx);
2086− for link in links.into_iter().rev() {
2087− current = self.complete(link, current, ctx)?;
2092− /// Give a resolved `@name` its children: an element holds them, and a
2093− /// function's body puts them where its `@children` is.
2096− resolved: Resolved,
2097− children: Vec<Node>,
2098− ctx: &mut ParseContext,
2099− ) -> Result<Vec<Node>, ParseError> {
2101− Resolved::Element(mut element) => {
2102− element.children.extend(children);
2103− let line = element.line_num;
2104− Ok(vec![inline_svg(Node::Element(element), line, ctx)])
2106− Resolved::Call(call) => self.expand_fn_call(*call, children, ctx),
2113− all_caller_children: Vec<Node>,
2114− ctx: &mut ParseContext,
2115− ) -> Result<Vec<Node>, ParseError> {
2121− text: trailing_text,
2128− let (name, content) = (name.as_str(), content.as_str());
2130− // Separate the caller's `@slot NAME` blocks from its other
2131− // children. A block for a slot the function doesn't declare was
2132− // reported where it is written (see `check_fillers`), like one
2134− let mut slot_contents: HashMap<String, Vec<Node>> = HashMap::new();
2135− let mut caller_children = Vec::new();
2136− for child in all_caller_children {
2137− if let Node::Element(elem) = child {
2139− ElementKind::Slot(slot_name) => {
2143− .extend(elem.children);
2145− kind => caller_children.push(Node::Element(Element { kind, ..elem })),
2149− caller_children.push(child);
2151− // Text after the call, as in `@card [color red] New`, is content:
2152− // it goes first among the caller's children, and like them it is
2153− // evaluated where the call is written.
2154− if let Some(text) = &trailing_text {
2155− caller_children.insert(0, Node::Text(text_segments(text, ctx)));
2157− // Content goes where the body's `@children` is: without one, it
2158− // would be dropped
2159− if !fn_def.has_children && !caller_children.is_empty() {
2160− let (column, text) = match &name_at {
2161− Some((column, text)) => (Some(*column), text.as_str()),
2162− None => (None, content),
2164− ctx.push_once(no_children(name, line_num, column).source(text));
2167− if fn_def.wraps_itself {
2168− return Ok(Vec::new());
2170− // Only the body is inside the call, so a function may appear in the
2171− // content its caller passes it. A function may call itself, under
2172− // a condition that stops it; one that doesn't stop goes too deep.
2174− return Ok(Vec::new());
2176− if ctx.fn_call_stack.len() >= MAX_CALL_DEPTH {
2177− ctx.too_deep = true;
2178− return Err(too_deep(name, &ctx.fn_call_stack, line_num).source(content));
2182− ctx.current_source.clone(),
2185− ctx.fn_call_stack.push(name.to_string());
2187− // The body runs where the function is defined: it sees what was
2188− // visible there, the function itself (so it can call itself), and
2189− // its parameters, bound by name in the order they are declared. A
2190− // default is filled in at the call, seeing the same, with the
2191− // parameters before it.
2192− let caller_env = std::mem::replace(&mut ctx.env, fn_def.env.clone());
2194− ctx.env.define(name, Binding::Function(fn_def.clone()));
2195− let mut consumed = vec![false; args.len()];
2196− for param in &fn_def.params {
2197− let mut passed = None;
2198− for (j, arg) in args.iter().enumerate() {
2199− if arg.key != param.name {
2202− consumed[j] = true;
2203− // The later one wins, as for any attribute: one written
2204− // after a bundle overrides it, and only one written twice
2205− // in the call's own list is reported
2206− if passed.is_some() && written_keys.iter().filter(|k| **k == param.name).count() > 1
2209− Diagnostic::warning(
2210− code::DUPLICATE_ATTRIBUTE,
2213− "parameter '{}' of @{} is passed twice: the later one wins",
2218− .subject(param.name.as_str()),
2221− // Written `name=value` in the call's own list is reported
2222− // as written; this is one from a bundle
2223− if arg.html && !written_form.contains(&arg.key) {
2224− let value = arg.value.as_deref().unwrap_or("");
2225− ctx.push_once(parameter_form(name, &arg.key, value, line_num).source(content));
2229− let value = match passed {
2230− // A parameter's name alone is true: `@post-card [featured]`
2231− Some(j) if args[j].value.is_none() => Value::Bool(true),
2232− // What the call passed, with its type: a record, a list,
2234− Some(j) => values[j].clone().unwrap_or_else(|| {
2235− let arg = &args[j];
2236− match &arg.quoted {
2237− Some(quoted) => Value::Quoted(quoted.clone()),
2238− None => Value::Str(arg.value.clone().unwrap_or_default()),
2241− None => match ¶m.default {
2243− let before = ctx.diagnostics.len();
2244− let value = fill_default(&fn_def, param, default, ctx);
2245− point_at_call(ctx, before, &fn_def, name, line_num, content);
2249− let (column, text) = match &name_at {
2250− Some((column, text)) => (Some(*column), text.as_str()),
2251− None => (None, content),
2254− missing_parameter(name, ¶m.name, line_num, column).source(text),
2260− ctx.bind(¶m.name, value);
2262− // Arguments that aren't parameters are attributes for the
2263− // function's root element, so a function can be styled like an
2264− // element: `@card [background red] New`.
2265− let forwarded: Vec<Attribute> = args
2268− .filter(|&(_, &used)| !used)
2269− .map(|(a, _)| a.clone())
2272− // Evaluate the body with the parameters in scope, as lines of the
2273− // file that defines the function
2274− let caller_file = std::mem::replace(&mut ctx.current_file, fn_def.file.clone());
2275− let before = ctx.diagnostics.len();
2276− let mut body_nodes = self.eval_block(&fn_def.body, ctx);
2277− ctx.current_file = caller_file;
2278− point_at_call(ctx, before, &fn_def, name, line_num, content);
2280− // Back to the caller's names and call stack
2281− ctx.env = caller_env;
2282− ctx.fn_call_stack.pop();
2283− if ctx.fn_call_stack.is_empty() {
2284− ctx.too_deep = false;
2286− (ctx.current_line, ctx.current_source, ctx.current_node) = caller;
2288− // What the body wrote is the call's
2289− belongs_to_call(&mut body_nodes, name, line_num);
2291− // Replace @children with caller's children and @slot with slot content
2292− let mut result_nodes =
2293− replace_children_and_slots(body_nodes, &caller_children, &slot_contents);
2295− // Attributes that aren't parameters style the function's root
2296− // element, and a scoped @style's class goes on it too.
2297− let scope_class = fn_def.scoped.as_ref().map(|(class, _)| class.clone());
2298− if !forwarded.is_empty() || scope_class.is_some() {
2299− let mut roots = result_nodes.iter_mut().filter_map(|n| match n {
2300− Node::Element(e) => Some(e),
2303− let root = match (roots.next(), roots.next()) {
2304− (Some(root), None) => Some(root),
2307− let mut problems = Vec::new();
2310− // A call's `class=` adds to the root's own classes
2311− for attr in forwarded {
2312− let existing = (attr.html && attr.key == "class")
2313− .then(|| root.attrs.iter_mut().find(|a| a.html && a.key == "class"))
2317− let mut value = class.value.take().unwrap_or_default();
2318− for name in attr.value.as_deref().unwrap_or("").split_whitespace() {
2319− if !value.split_whitespace().any(|c| c == name) {
2321− value.push_str(name);
2324− class.value = Some(value.trim().to_string());
2326− None => root.attrs.push(attr),
2329− // The scoped `@style` goes into the page once, when the
2330− // function is first called
2331− if let Some((_, css)) = &fn_def.scoped
2333− && !ctx.scoped_css.contains(css)
2335− ctx.scoped_css.push(css.clone());
2337− if let Some(class) = scope_class {
2338− match root.attrs.iter_mut().find(|a| a.html && a.key == "class") {
2340− let existing = attr.value.take().unwrap_or_default();
2342− Some(format!("{} {}", existing, class).trim().to_string());
2344− None => root.attrs.push(Attribute {
2345− key: "class".to_string(),
2346− value: Some(class),
2354− if !forwarded.is_empty() {
2355− problems.push(format!(
2356− "attributes {} on @{} are not parameters, and its body has no single \
2357− root element to receive them",
2360− .map(|a| format!("'{}'", a.key))
2361− .collect::<Vec<_>>()
2366− if scope_class.is_some() {
2367− problems.push(format!(
2368− "@{} has a scoped @style, but its body has no single root element \
2375− for message in problems {
2376− ctx.diagnostics.push(
2377− Diagnostic::error(code::NO_SINGLE_ROOT, line_num, message)
2388−/// A `@name` read where it is written: a built-in element, or a call.
2394−/// A call of a function, with its arguments evaluated where it is written.
2397− function: Rc<FnDef>,
2398− args: Vec<Attribute>,
2399− /// The value of each argument that passes a parameter, with its type
2400− /// (see [`ParseContext::slot_value`]), in the order of `args`.
2401− values: Vec<Option<Value>>,
2402− /// Text after the attributes, which is content.
2403− text: Option<syntax::Text>,
2404− /// Parameters written `name=value`, already reported.
2405− written_form: Vec<String>,
2406− /// The keys written in the call's own list, not from a bundle.
2407− written_keys: Vec<String>,
2409− /// The column of the call's name and the line it is on, for a missing
2411− name_at: Option<(usize, String)>,
2412− /// The line as written, for diagnostics.
2416−/// What `@name` is where it is written: a call of the function `name`
2417−/// when one is defined, else the built-in element. A whole line, each link
2418−/// of a chain and an inline element in text all resolve here.
2420− head: &syntax::Head,
2421− text: Option<&syntax::Text>,
2424− ctx: &mut ParseContext,
2425−) -> Result<Resolved, ParseError> {
2426− let Some(function) = ctx.env.function(&head.name).cloned() else {
2427− return parse_single_element(head, text, line, ctx).map(Resolved::Element);
2429− ctx.used_functions.insert(head.name.clone());
2430− let params: Vec<String> = function.params.iter().map(|p| p.name.clone()).collect();
2431− let written = head.attrs.as_ref().map_or(&[][..], |list| &list.attrs[..]);
2432− let written_form = written_parameter_forms(&head.name, &function, written, line, ctx);
2433− let written_keys = written.iter().map(|a| a.key.clone()).collect();
2434− // Parameters are bound by name; every other attribute goes to the
2435− // root element, and is checked like any attribute
2436− let (args, values) = parse_attrs(written, line, ctx, true, ¶ms)
2439− let name_at = name_column(head, line).zip(match &ctx.current_source {
2440− (current, Some(text)) if *current == line => Some(text.clone()),
2443− Ok(Resolved::Call(Box::new(Call {
2444− name: head.name.clone(),
2448− text: text.cloned(),
2453− source: source.to_string(),
2457−/// A line of another file (the standard library, an included file) means
2458−/// nothing in this one: the problems reported since `before` while
2459−/// evaluating the function (its body, a default) are moved to the call.
2461− ctx: &mut ParseContext,
2468− if function.file == ctx.current_file {
2471− let defined_in = function
2474− .unwrap_or("the file being compiled");
2475− for d in &mut ctx.diagnostics[before..] {
2476− d.message = format!(
2477− "{}\n in @{} (line {} of {})",
2478− d.message, name, d.line, defined_in
2483− d.suggestion = None;
2484− d.source_line = Some(source.into());
2488−/// A call nested deeper than [`MAX_CALL_DEPTH`].
2489−fn too_deep(name: &str, stack: &[String], line: usize) -> Diagnostic {
2490− let message = if stack.iter().any(|n| n == name) {
2492− "recursive function call to @{} goes more than {} calls deep: a function that \
2493− calls itself needs a condition that stops it (`@if`)",
2494− name, MAX_CALL_DEPTH
2498− "function calls nest more than {} deep at @{} (starting with {})",
2504− .map(|n| format!("@{}", n))
2505− .collect::<Vec<_>>()
2509− Diagnostic::error(code::RECURSIVE_CALL, line, message).subject(name)
2512−/// Mark what a function's body wrote as the call's: it gets the call's
2513−/// line, so what is reported about it points at the call, and the name of
2514−/// the function, unless a call inside the body already claimed it.
2515−fn belongs_to_call(nodes: &mut [Node], function: &str, line: usize) {
2516− fn claim(element: &mut Element, function: &str, line: usize) {
2517− element.line_num = line;
2518− element.function.get_or_insert_with(|| function.to_string());
2519− belongs_to_call(&mut element.children, function, line);
2521− for node in nodes {
2523− Node::Element(element) => claim(element, function, line),
2524− Node::Text(segments) => {
2525− for segment in segments {
2526− if let TextSegment::Inline(element) = segment {
2527− claim(element, function, line);
2536−/// What an inline `{@name ...}` stands for in its line of text: an
2537−/// element; the text of a function whose body is text; or, for a body with
2538−/// several roots, its nodes as a fragment.
2539−fn inline_segments(mut nodes: Vec<Node>, line: usize) -> Vec<TextSegment> {
2540− if let [Node::Element(_)] = nodes.as_slice()
2541− && let Some(Node::Element(element)) = nodes.pop()
2543− return vec![TextSegment::Inline(element)];
2545− if nodes.iter().all(|n| matches!(n, Node::Text(_))) {
2546− let mut segments = Vec::new();
2547− for node in nodes {
2548− if let Node::Text(run) = node {
2549− if !segments.is_empty() {
2550− segments.push(TextSegment::Plain(" ".to_string()));
2552− segments.extend(run);
2557− vec![TextSegment::Inline(Element {
2558− kind: ElementKind::Fragment,
2567−/// Fill in the default of a parameter that a call leaves out, like the
2568−/// value of an attribute passed for it: variables are filled in, one
2569−/// `$name` keeps its type and one `"..."` is quoted text. It sees what the
2570−/// body sees: the names visible where the function is defined, and the
2571−/// parameters before it. Its problems are reported at the definition, once.
2574− param: &syntax::Param,
2576− ctx: &mut ParseContext,
2578− // A default that uses a later parameter is an error in the
2579− // definition; the later one isn't bound yet, so don't report it again
2583− .skip_while(|p| p.name != param.name)
2585− let names = interp::names(default);
2586− if later.clone().any(|p| names.contains(&p.name.as_str())) {
2587− return Value::empty();
2589− let line = param.span.line;
2590− let at_head = line == fn_def.line && fn_def.source.is_some();
2592− at_head.then(|| param.span.column + (param.span.end - param.span.start) - default.len());
2595− &mut ctx.current_source,
2596− (fn_def.line, fn_def.source.clone()),
2598− std::mem::replace(&mut ctx.current_node, fn_def.node),
2600− let (value, _) = ctx.slot_value(default, line, column);
2601− (ctx.current_source, ctx.current_node) = caller;
2605−/// Read `@page`'s attribute list and title. The page is the root element,
2606−/// and its attributes are checked like any element's: `key=value` (and a
2607−/// bare boolean HTML attribute) go on `<html>`, styles on `<body>`, and
2608−/// `favicon FILE` is its one word of htmlang's own.
2610− attrs: Option<&syntax::AttrList>,
2611− title: Option<&syntax::Arg>,
2613− ctx: &mut ParseContext,
2615− let mut page = Page::default();
2616− if let Some(list) = attrs {
2617− let words: Vec<String> = crate::vocab::PAGE_WORDS
2619− .map(|w| w.to_string())
2621− ctx.in_page = true;
2622− let read = parse_attr_list(&list.attrs, line, ctx, true, &words);
2623− ctx.in_page = false;
2624− // How many of each name have been read, to find where the next
2626− let mut seen: HashMap<String, usize> = HashMap::new();
2628− let boolean = attr.value.is_none() && crate::vocab::is_html_flag(&attr.key);
2629− // Where it is written, when it is written in the list itself
2630− let nth = seen.entry(attr.key.clone()).or_default();
2634− .filter(|token| token.key == attr.key)
2636− .map(|token| token.span.column);
2641− .map(|q| q.text.clone())
2642− .or(attr.value.clone());
2643− if !check_page_attr(&attr.key, attr.html, value.as_deref(), line, column, ctx) {
2646− if words.contains(&attr.key) {
2647− if page.favicon.is_some() {
2648− let diagnostic = Diagnostic::warning(
2649− code::DUPLICATE_ATTRIBUTE,
2651− "duplicate attribute 'favicon': the later one wins".to_string(),
2653− .subject("favicon");
2654− ctx.diagnostics.push(at_attribute(diagnostic, column, ctx));
2656− // The file itself goes into the page when it can be read
2657− // (relative to the file); otherwise it is linked
2658− page.favicon = value.map(|path| match std::fs::read(ctx.resolve(&path)) {
2659− Ok(data) => crate::codegen::data_uri(&path, &data),
2662− } else if attr.html || boolean {
2663− page.html_attrs.push(attr);
2665− page.styles.push(attr);
2669− page.title = match title {
2670− Some(title) => ctx.interpolate_text(&title.raw, title.span.line, Some(title.span.column)),
2671− None => String::new(),
2676−/// `@page`'s own rules for one of its attributes, checked where the
2677−/// `@page` runs and where it doesn't (a layout that isn't called): its
2678−/// word is written `favicon FILE`, and `inline` belongs to `@image`.
2679−/// Returns whether the attribute can be used (a `favicon` with its file,
2680−/// or any other attribute but `inline`).
2684− value: Option<&str>,
2686− column: Option<usize>,
2687− ctx: &mut ParseContext,
2689− let report = |ctx: &mut ParseContext, diagnostic: Diagnostic| {
2690− let diagnostic = at_attribute(diagnostic, column, ctx);
2691− ctx.diagnostics.push(diagnostic);
2693− if crate::vocab::PAGE_WORDS.contains(&key) {
2698− code::PARAMETER_FORM,
2701− "'{0}' is @page's own word, not an HTML attribute: write `{0} {1}`",
2703− value.filter(|v| !v.is_empty()).unwrap_or("FILE")
2706− .subject(format!("{}=", key))
2707− .suggest(Some(format!("{} ", key))),
2710− if value.is_none_or(|v| v.trim().is_empty()) {
2714− code::MISSING_VALUE,
2716− format!("'{0}' needs its file: `{0} favicon.png`", key),
2724− if !html && crate::vocab::base_attribute(key) == "inline" {
2728− code::UNEXPECTED_ARGUMENT,
2730− "`inline` puts an image's file into the page, and @page has none: it only \
2734− .subject("inline"),
2741−/// A parameter passed `name=value`, the form of an HTML attribute.
2742−fn parameter_form(function: &str, key: &str, value: &str, line: usize) -> Diagnostic {
2744− code::PARAMETER_FORM,
2747− "'{}' is a parameter of @{}: parameters are written `name value`, so write `{} {}`",
2748− key, function, key, value
2751− .subject(format!("{}=", key))
2752− .suggest(Some(format!("{} ", key)))
2755−/// A call that leaves out a parameter without a default.
2756−fn missing_parameter(
2760− column: Option<usize>,
2762− let diagnostic = Diagnostic::error(
2763− code::MISSING_PARAMETER,
2766− "@{} needs '{}': the parameter has no default, so pass it as `{} VALUE`",
2767− function, param, param
2772− Some(column) => diagnostic.column(column),
2773− None => diagnostic,
2777−/// The column of a call's `@name`, when it is on the call's line.
2778−fn name_column(head: &syntax::Head, line: usize) -> Option<usize> {
2779− (head.name_span.line == line).then_some(head.name_span.column)
2782−/// Define `$name`, or, for `--name`, the CSS custom property on `:root`
2783−/// (which gets quoted text with its quotes, and is read with
2784−/// `var(--name)`, never as a variable). `@let name.field value` gives the
2785−/// record `$name` that field (or the list `$name` a new item at that
2786−/// index), as a new value in this block.
2787−fn set_variable(name: &str, value: Value, line_num: usize, ctx: &mut ParseContext) {
2788− if name.starts_with("--") {
2791− .map_or_else(|| value.to_string(), str::to_string);
2792− let at_line = |diagnostic: Diagnostic, ctx: &ParseContext| match &ctx.current_source {
2793− (current, Some(text)) if *current == line_num => diagnostic.source(text.clone()),
2796− // `:root` is one place for the whole page: a declaration inside a
2797− // block (an element, a loop, a function's body) would not be
2798− // kept to it, and each run would replace the last
2799− if ctx.env.frames.len() > FILE_FRAMES {
2800− let diagnostic = Diagnostic::error(
2801− code::INVALID_DEFINITION,
2804− "`@let {name}` declares {name} on :root, for the whole page, so it goes at \
2805− the top level of the file: to set it on an element and what is inside \
2806− it, write `[{name} value]` on that element"
2810− ctx.push_once(at_line(diagnostic, ctx));
2813− match css_breakout(&css) {
2815− let diagnostic = Diagnostic::error(
2816− code::INVALID_VALUE,
2819− "the value of '{}' has {}: `{}` can't be written into the page's CSS",
2823− .subject(css.as_str());
2824− ctx.push_once(at_line(diagnostic, ctx));
2826− None => match ctx.css_vars.iter_mut().find(|(n, _)| n == name) {
2827− Some(declared) => {
2828− let diagnostic = Diagnostic::warning(
2829− code::DUPLICATE_ATTRIBUTE,
2832− "{name} is declared again: :root has one value for the whole page, \
2833− so every element gets this one, also above this line (a theme \
2834− redefines a token on an element: `[dark:{name} {css}]`)"
2839− ctx.push_once(at_line(diagnostic, ctx));
2841− None => ctx.css_vars.push((name.to_string(), css)),
2846− let mut path = name.split('.');
2847− let root = path.next().unwrap_or(name);
2848− let fields: Vec<&str> = path.collect();
2849− let value = match fields.is_empty() {
2851− false => match with_field(ctx.env.value(root).cloned(), root, &fields, value) {
2852− Ok(value) => value,
2855− Diagnostic::error(code::INVALID_DEFINITION, line_num, message).subject(name);
2856− let diagnostic = match &ctx.current_source {
2857− (current, Some(text)) if *current == line_num => {
2858− diagnostic.source(text.clone())
2862− ctx.push_once(diagnostic);
2863− // Reported: the name keeps what it held
2864− ctx.let_lines.entry(root.to_string()).or_insert(line_num);
2869− ctx.bind(root, value);
2870− ctx.let_lines.entry(root.to_string()).or_insert(line_num);
2873−/// `value` (the value of `$name`) with the field at `path` set to `new`:
2874−/// a record's field, or the item of a list at an index it has. A name
2875−/// without a value, or one whose value is empty (a field a record doesn't
2876−/// have), becomes a record; any other value has no fields to set.
2878− value: Option<Value>,
2882−) -> Result<Value, String> {
2883− let Some((field, rest)) = path.split_first() else {
2886− let inner = format!("{}.{}", name, field);
2888− Some(Value::Record(fields)) => {
2889− let mut fields = fields.as_ref().clone();
2890− match fields.iter().position(|(key, _)| key == field) {
2892− let old = std::mem::replace(&mut fields[i].1, Value::empty());
2893− fields[i].1 = with_field(Some(old), &inner, rest, new)?;
2895− None => fields.push((field.to_string(), with_field(None, &inner, rest, new)?)),
2897− Ok(Value::Record(Rc::new(fields)))
2899− Some(Value::List(list)) => {
2900− let count = list.items.len();
2901− let Some(i) = field.parse::<usize>().ok().filter(|&i| i < count) else {
2902− return Err(format!(
2903− "`${}` is {}, so `.{}` isn't one of its items (they are `.0` to `.{}`)",
2905− Value::List(list).describe(),
2907− count.saturating_sub(1)
2910− let mut items = list.items.as_ref().clone();
2911− let old = std::mem::replace(&mut items[i], Value::empty());
2912− items[i] = with_field(Some(old), &inner, rest, new)?;
2913− // Its items changed, so it no longer prints as written
2914− Ok(Value::list(items))
2916− None => Ok(Value::Record(Rc::new(vec![(
2918− with_field(None, &inner, rest, new)?,
2920− Some(value) if value.to_string().is_empty() => with_field(None, name, path, new),
2921− Some(value) => Err(format!(
2922− "`@let {}.{}` sets a field of a record, but `${}` is {} (`{}`), which has no fields",
2932−/// What a verbatim directive holds (`@head`, `@style`, `@raw`): the rest
2933−/// of its line (`@style .a { color: red }`), or else its indented block.
2934−/// The two together are a syntax error, reported by the tree; the line
2936−fn verbatim_content(node: &syntax::Node) -> String {
2937− match node.directive().map(|d| &d.args) {
2938− Some(DirectiveArgs::Text(Some(line))) => format!("{}\n", line.raw),
2939− _ => verbatim_text(&node.children),
2943−/// The text of a verbatim body (`@head`, `@style`, `@markdown`, `@raw`).
2944−fn verbatim_text(children: &[syntax::Node]) -> String {
2945− let mut text = String::new();
2946− for child in children {
2947− if let NodeKind::Verbatim(body) = &child.kind {
2948− text.push_str(&body.text);
2955−// ---------------------------------------------------------------------------
2956−// @children replacement
2957−// ---------------------------------------------------------------------------
2959−fn replace_children_and_slots(
2961− caller_children: &[Node],
2962− slot_contents: &HashMap<String, Vec<Node>>,
2964− let mut result = Vec::new();
2965− for node in nodes {
2967− Node::Element(elem) if elem.kind == ElementKind::Children => {
2968− if caller_children.is_empty() && !elem.children.is_empty() {
2969− // Use @children's own children as default/fallback content
2970− result.extend(elem.children);
2972− result.extend(caller_children.iter().cloned());
2975− Node::Element(elem) if matches!(&elem.kind, ElementKind::Slot(name) if !name.is_empty()) =>
2977− if let ElementKind::Slot(ref name) = elem.kind {
2978− if let Some(content) = slot_contents.get(name) {
2979− result.extend(content.iter().cloned());
2981− // If no content provided for this slot, use the slot's own children as default
2982− else if !elem.children.is_empty() {
2983− result.extend(elem.children);
2987− Node::Element(mut elem) => {
2989− replace_children_and_slots(elem.children, caller_children, slot_contents);
2990− result.push(Node::Element(elem));
2992− other => result.push(other),
2998−// ---------------------------------------------------------------------------
2999−// Where @slot and @children are written
3000−// ---------------------------------------------------------------------------
3002−/// The files each `@include` line brought in, by the line's node id, with
3003−/// the include chain that leads to each.
3004−type IncludedBy = HashMap<usize, Vec<(Rc<Tree>, String)>>;
3006−/// The lines of the files an `@include` line brings in, and the include
3007−/// chain of each (for diagnostics).
3008−type Included<'a, 'f> = &'f dyn Fn(&syntax::Node) -> Vec<(&'a [syntax::Node], Option<&'a str>)>;
3010−/// Whether `name` is a function here: defined so far, or anywhere in the
3011−/// file and the files it includes.
3012−fn is_function(name: &str, ctx: &ParseContext) -> bool {
3013− ctx.env.function(name).is_some() || ctx.namespace.contains(name)
3016−/// Whether `name` is one slot name: letters, digits, `-` and `_`,
3017−/// starting with a letter (like a function's name).
3018−fn is_slot_name(name: &str) -> bool {
3019− name.chars().next().is_some_and(char::is_alphabetic)
3022− .all(|c| c.is_alphanumeric() || c == '-' || c == '_')
3025−/// What a `@slot` or `@children` line is written in.
3026−#[derive(Clone, Copy)]
3028− /// The top of a file or of a function's body, or a built-in element
3030− Element(Option<&'a str>),
3031− /// A call: its content.
3035−/// Where a line is, for [`slot_uses`].
3036−#[derive(Clone, Copy)]
3038− /// Inside a function's body.
3041− /// Outside a body: the call (and its line) whose content it is in.
3042− call: Option<(&'a str, usize)>,
3043− /// The include chain of the file it is in, when that isn't the file
3044− /// being compiled.
3045− file: Option<&'a str>,
3049− /// The top of a file, or of a function's body.
3050− fn top(body: bool) -> Self {
3053− place: Place::Element(None),
3060−/// What [`slot_uses`] knows about the names and files it walks.
3061−struct Scan<'a, 'f> {
3062− is_function: &'f dyn Fn(&str) -> bool,
3063− included: Included<'a, 'f>,
3064− /// Visit the bodies of the functions defined in the lines too.
3068−/// A `@slot` or `@children` written in a file, and where.
3069−struct SlotUse<'a> {
3070− node: &'a syntax::Node,
3071− head: &'a syntax::Head,
3072− /// The text after it, which is a slot's name; `None` when it isn't
3073− /// the last head of its chain.
3074− text: Option<&'a syntax::Text>,
3075− /// Written inline in a line of text, `{@slot x}`.
3081− fn is_slot(&self) -> bool {
3082− self.head.name == "slot"
3085− /// The slot's name as written.
3086− fn name(&self) -> &str {
3087− self.text.map_or("", |t| t.raw.trim())
3090− /// A `@slot NAME` that marks a place in a function's body (not one
3091− /// that fills a slot of a call).
3092− fn declares(&self) -> bool {
3093− self.is_slot() && !self.inline && !matches!(self.at.place, Place::Call)
3097−/// Where each `@slot` and `@children` in `block` is written. A `@slot`
3098−/// directly under a call (under its `@if`, `@else` and `@each` too) fills
3099−/// one of its slots; anywhere else in a function's body it declares one.
3100−/// An included file's lines are where its `@include` is.
3102− block: &'a [syntax::Node],
3104− scan: &Scan<'a, '_>,
3105− out: &mut Vec<SlotUse<'a>>,
3108− text: &'a syntax::Text,
3109− node: &'a syntax::Node,
3111− scan: &Scan<'a, '_>,
3112− out: &mut Vec<SlotUse<'a>>,
3114− for segment in &text.segments {
3115− if let Segment::Inline(inline_element) = segment {
3116− let head = &inline_element.head;
3117− if matches!(head.name.as_str(), "slot" | "children")
3118− && !(scan.is_function)(&head.name)
3123− text: inline_element.text.as_ref(),
3128− if let Some(text) = &inline_element.text {
3129− inline(text, node, at, scan, out);
3134− for node in block {
3136− NodeKind::Directive(directive) => match &directive.args {
3137− DirectiveArgs::Let(def) if matches!(def.form, LetForm::Function(_)) => {
3138− if scan.into_lets {
3143− slot_uses(&node.children, top, scan, out);
3146− // A value's body is an error of its own
3147− DirectiveArgs::Let(_) => {}
3148− _ if directive.spec.body == BodyKind::Verbatim => {}
3149− // `@if`, `@else` and `@each` put their lines in place, and
3150− // `@include` its file's; the lines under a directive that
3151− // takes no body are its siblings
3153− for (lines, file) in (scan.included)(node) {
3154− slot_uses(lines, At { file, ..at }, scan, out);
3156− slot_uses(&node.children, at, scan, out);
3159− NodeKind::Element(line) => {
3161− let last = line.chain.len() - 1;
3162− for (i, head) in line.chain.iter().enumerate() {
3163− let text = if i == last { line.text.as_ref() } else { None };
3164− let function = (scan.is_function)(&head.name);
3165− if !function && matches!(head.name.as_str(), "slot" | "children") {
3173− } else if let Some(text) = text {
3174− inline(text, node, at, scan, out);
3177− at.place = Place::Call;
3179− at.call = Some((&head.name, node.span.line));
3182− at.place = Place::Element(Some(&head.name));
3185− slot_uses(&node.children, at, scan, out);
3187− NodeKind::Text(text) => {
3188− inline(text, node, at, scan, out);
3189− slot_uses(&node.children, at, scan, out);
3191− NodeKind::Blank | NodeKind::Comment | NodeKind::Verbatim(_) => {}
3196−/// The slots a function's body declares, and whether it has a
3197−/// `@children`, when it is defined. The files its `@include` lines bring
3198−/// in count too: they are read now, since they run only at a call.
3199−fn declared_slots(body: &[syntax::Node], ctx: &mut ParseContext) -> (Vec<String>, bool) {
3200− let mut files = HashMap::new();
3203− ctx.base_path.clone(),
3208− let included = |node: &syntax::Node| match files.get(&node.id) {
3209− Some(tree) => vec![(&tree.nodes[..], None)],
3210− None => Vec::new(),
3212− let is_function = |name: &str| is_function(name, ctx);
3213− slots_of(body, &is_function, &included)
3216−/// Read and parse the files the `@include` lines in `nodes` bring in (by
3217−/// a literal path, relative to `base`), and the files those include, by
3218−/// the node id of each `@include` line.
3220− nodes: &[syntax::Node],
3221− base: Option<PathBuf>,
3222− stack: &mut Vec<PathBuf>,
3223− ctx: &mut ParseContext,
3224− files: &mut HashMap<usize, Rc<Tree>>,
3226− let mut includes = Vec::new();
3227− for node in nodes {
3228− node.walk(&mut |node| {
3229− if let Some(DirectiveArgs::Text(Some(path))) = node.directive().map(|d| &d.args)
3230− && node.is_directive("include")
3232− includes.push((node.id, path.raw.clone()));
3236− for (id, path) in includes {
3237− let path = path.trim_matches('"');
3238− if path.contains('$') {
3241− let resolved = match &base {
3242− Some(base) => base.join(path),
3243− None => PathBuf::from(path),
3245− if stack.contains(&resolved) {
3248− let Ok(text) = ctx.read_file(&resolved) else {
3251− let tree = ctx.parse_tree(&text);
3252− stack.push(resolved.clone());
3253− let parent = resolved.parent().map(Path::to_path_buf);
3254− read_includes(&tree.nodes, parent, stack, ctx, files);
3256− files.insert(id, tree);
3260−/// The slots a function's body declares (`@slot NAME`, in order), and
3261−/// whether it has a `@children` for the content of a call. A `@slot`
3262−/// directly under a call in the body fills that call's slot instead, so
3263−/// `is_function` says which names are functions. The files the body
3264−/// includes aren't read.
3265−pub fn function_slots(
3266− body: &[syntax::Node],
3267− is_function: &dyn Fn(&str) -> bool,
3268−) -> (Vec<String>, bool) {
3269− slots_of(body, is_function, &|_| Vec::new())
3273− body: &'a [syntax::Node],
3274− is_function: &dyn Fn(&str) -> bool,
3275− included: Included<'a, '_>,
3276−) -> (Vec<String>, bool) {
3282− let mut uses = Vec::new();
3283− slot_uses(body, At::top(true), &scan, &mut uses);
3284− let mut slots: Vec<String> = Vec::new();
3285− for slot in uses.iter().filter(|u| u.declares()) {
3286− let name = slot.name();
3287− if is_slot_name(name) && !slots.iter().any(|s| s == name) {
3288− slots.push(name.to_string());
3291− let has_children = uses.iter().any(|u| !u.is_slot() && !u.inline);
3292− (slots, has_children)
3295−/// The line as written, indented, when it is one physical line, so a
3296−/// column points into it.
3297−fn written_line(node: &syntax::Node) -> String {
3298− match node.line_count <= 1 {
3299− true => format!("{}{}", " ".repeat(node.indent), node.source),
3300− false => node.source.clone(),
3304−/// The lines of the files an `@include` line brought in when it ran, from
3306−fn ran_includes<'a>(
3307− included_by: &'a IncludedBy,
3308− node: &syntax::Node,
3309−) -> Vec<(&'a [syntax::Node], Option<&'a str>)> {
3310− match included_by.get(&node.id) {
3311− Some(files) => files
3313− .map(|(tree, chain)| (&tree.nodes[..], Some(chain.as_str())))
3315− None => Vec::new(),
3319−/// Check where every `@slot` and `@children` of the file and the files it
3320−/// includes is written, whether or not it runs: a slot has one name, a
3321−/// function's body marks places with them, and a call fills its slots
3322−/// with `@slot` blocks directly under it. An included file's lines are
3323−/// where its `@include` is (in a body, under a call), so an `@include`
3324−/// that never ran leaves its file unchecked.
3325−fn check_slot_places(ctx: &mut ParseContext) {
3326− let trees = std::mem::take(&mut ctx.trees);
3327− let included_by = ctx.included_by.clone();
3328− let is_function = |name: &str| is_function(name, ctx);
3330− is_function: &is_function,
3331− included: &|node| ran_includes(&included_by, node),
3334− let mut uses = Vec::new();
3335− for (tree, _) in trees.iter().filter(|(_, chain)| chain.is_none()) {
3336− slot_uses(&tree.nodes, At::top(false), &scan, &mut uses);
3338− let found: Vec<Diagnostic> = uses
3340− .filter_map(|slot| {
3341− let mut d = slot_problem(slot)?;
3342− if d.column.is_none() {
3343− d = d.column(slot.head.name_span.column);
3345− d = d.source(written_line(slot.node));
3346− if let Some(file) = slot.at.file {
3347− d.message = format!("{}\n in {}", d.message, file);
3352− ctx.diagnostics.extend(found);
3356−/// What is wrong with a `@slot` or `@children` where it is written.
3357−fn slot_problem(slot: &SlotUse) -> Option<Diagnostic> {
3358− let line = slot.node.span.line;
3359− let what = if slot.is_slot() {
3360− match slot.name() {
3361− "" => "@slot".to_string(),
3362− name => format!("@slot {}", name),
3365− "@children".to_string()
3368− return Some(Diagnostic::error(
3369− code::MISPLACED_SLOT,
3372− "{} goes on a line of its own: inline in text it marks and fills nothing",
3377− if let Some(list) = &slot.head.attrs {
3380− code::UNEXPECTED_ARGUMENT,
3383− "{} takes no attributes: it is replaced by content, so style the \
3384− element around it",
3388− .column(list.span.column),
3391− if slot.is_slot() {
3392− let name = slot.name();
3393− if name.is_empty() {
3394− return Some(Diagnostic::error(
3395− code::MISSING_ARGUMENT,
3397− "@slot needs a name: `@slot footer` (the caller's content without a \
3398− name goes where `@children` is)"
3402− if !is_slot_name(name) {
3403− let joined = name.split_whitespace().collect::<Vec<_>>().join("-");
3404− let suggestion = is_slot_name(&joined).then_some(joined);
3405− let column = slot.text.map(|t| t.span.column);
3406− let d = Diagnostic::error(
3407− code::INVALID_SLOT_NAME,
3410− "'{}' is not a slot name: a slot's name is one word of letters, digits, \
3411− `-` and `_`, starting with a letter, and its content goes on the lines \
3417− .suggest(suggestion);
3418− return Some(match column {
3419− Some(column) => d.column(column),
3423− if matches!(slot.at.place, Place::Call) || slot.at.body {
3426− let message = match (slot.at.call, slot.at.place) {
3427− (Some((call, call_line)), Place::Element(Some(element))) => format!(
3428− "{} is inside @{}, so it fills nothing: a @slot block that fills a slot of \
3429− @{} (line {}) goes directly under the call",
3430− what, element, call, call_line
3433− "{} is outside a function's body: `@slot NAME` marks a place in a body \
3434− (`@let @name`), and directly under a call it fills one",
3438− return Some(Diagnostic::error(code::MISPLACED_SLOT, line, message));
3443− let message = match slot.at.call {
3444− Some((call, _)) => format!(
3445− "@children is outside a function's body, so it stands for nothing: the content \
3446− for @{} is written directly under the call",
3449− None => "@children is outside a function's body: it marks where a body puts the \
3450− content of each call"
3453− Some(Diagnostic::error(code::MISPLACED_SLOT, line, message))
3456−/// A `@slot NAME` block that fills a slot of a call.
3458− node: &'a syntax::Node,
3459− text: &'a syntax::Text,
3460− /// The include chain of the file it is in, when that isn't the file
3461− /// being compiled.
3462− file: Option<&'a str>,
3465−/// Whether `@slot` is the built-in element here, and not a function
3466−/// defined so far that took its name.
3467−fn slot_is_built_in(ctx: &ParseContext) -> bool {
3468− ctx.env.function("slot").is_none()
3471−/// The `@slot NAME` blocks directly under a call, in `block` (under its
3472−/// `@if`, `@else` and `@each` too, and in the files its `@include` lines
3475− block: &'a [syntax::Node],
3476− file: Option<&'a str>,
3477− included: &'a IncludedBy,
3478− out: &mut Vec<Filler<'a>>,
3480− for node in block {
3482− NodeKind::Directive(directive)
3483− if matches!(directive.name(), "if" | "else" | "each") =>
3485− fillers(&node.children, file, included, out);
3487− NodeKind::Directive(directive) if directive.name() == "include" => {
3488− for (lines, file) in ran_includes(included, node) {
3489− fillers(lines, file, included, out);
3492− NodeKind::Element(line) if line.chain.len() == 1 && line.chain[0].name == "slot" => {
3493− if let Some(text) = &line.text {
3494− out.push(Filler { node, text, file });
3502−/// Whether `block`, the lines under a call, holds content other than
3503−/// `@slot` blocks (under `@if`, `@else` and `@each` too): text, an
3504−/// element, raw HTML, Markdown or an included file. For code that doesn't
3506−fn holds_content(block: &[syntax::Node], ctx: &ParseContext) -> bool {
3507− block.iter().any(|node| match &node.kind {
3508− NodeKind::Directive(directive) => match directive.name() {
3509− "if" | "else" | "each" => holds_content(&node.children, ctx),
3510− name => matches!(name, "raw" | "markdown" | "include"),
3512− NodeKind::Element(line) => {
3513− line.chain[0].name != "slot" || !slot_is_built_in(ctx) || line.chain.len() > 1
3515− NodeKind::Text(_) => true,
3520−/// Check the `@slot NAME` blocks passed to each call of a line against
3521−/// the slots its function declares. `calls` has the function of each head
3522−/// of the chain that is a call.
3524− node: &syntax::Node,
3525− element: &syntax::ElementLine,
3526− calls: &[Option<(String, Rc<FnDef>)>],
3527− ctx: &mut ParseContext,
3529− if !slot_is_built_in(ctx) {
3532− let included = ctx.included_by.clone();
3533− let last = element.chain.len() - 1;
3534− for (i, call) in calls.iter().enumerate() {
3535− let Some((name, function)) = call else {
3538− let mut found = Vec::new();
3540− fillers(&node.children, None, &included, &mut found);
3541− } else if i + 1 == last
3542− && element.chain[last].name == "slot"
3543− && let Some(text) = &element.text
3545− // `@card > @slot footer`
3546− found.push(Filler {
3552− for filler in found {
3553− let slot = filler.text.raw.trim();
3554− if !is_slot_name(slot) || function.slots.iter().any(|s| s == slot) {
3557− let mut d = unknown_slot(name, slot, &function.slots, filler.text.span.line)
3558− .column(filler.text.span.column)
3559− .source(written_line(filler.node));
3560− if let Some(file) = filler.file {
3561− d.message = format!("{}\n in {}", d.message, file);
3568−/// A `@slot NAME` block for a slot the function doesn't declare.
3569−fn unknown_slot(function: &str, slot: &str, slots: &[String], line: usize) -> Diagnostic {
3570− let candidates: Vec<&str> = slots.iter().map(String::as_str).collect();
3571− let suggestion = suggest_closest(slot, &candidates);
3572− let message = match (slots.is_empty(), suggestion) {
3573− (true, _) => format!(
3574− "@{} has no slot '{}': its body declares no slots (`@slot NAME`)",
3577− (false, Some(close)) => format!(
3578− "@{} has no slot '{}', did you mean '{}'? (its slots: {})",
3584− (false, None) => format!(
3585− "@{} has no slot '{}' (its slots: {})",
3591− Diagnostic::error(code::UNKNOWN_SLOT, line, message)
3593− .suggest(suggestion)
3596−/// Content passed to a function whose body has no `@children`.
3597−fn no_children(function: &str, line: usize, column: Option<usize>) -> Diagnostic {
3598− let d = Diagnostic::error(
3599− code::UNEXPECTED_CONTENT,
3602− "@{0} takes no content: its body has no `@children`, so the text and lines \
3603− passed to it would be dropped (pass text as a parameter, `@{0} [name value]`, \
3604− or add `@children` to the body)",
3608− .subject(function);
3610− Some(column) => d.column(column),
3615−// ---------------------------------------------------------------------------
3617−// ---------------------------------------------------------------------------
3619−/// Build the element for `@name [attrs] text` (on its own line, in a chain,
3620−/// or inline in text).
3621−fn parse_single_element(
3622− head: &syntax::Head,
3623− text: Option<&syntax::Text>,
3625− ctx: &mut ParseContext,
3626−) -> Result<Element, ParseError> {
3627− let kind = parse_element_kind(&head.name, line_num, ctx)?;
3628− let mut attrs = head.attrs.as_ref().map_or_else(Vec::new, |list| {
3629− parse_attr_list(&list.attrs, line_num, ctx, true, &[])
3632− // The leading argument: for an element whose row names a leading
3633− // attribute (`@link`'s href, `@image`'s src, `@form`'s action, ...),
3634− // the first token of the text fills it, split before anything is
3635− // filled in, and the rest is content (an error on an element without
3636− // content). `@slot`'s whole text is its name. Any other element's text
3637− // is content, parsed like any line of text, as in `@el [padding 8]
3638− // Hello` or `@h2 Meet {@text htmlang}`; its layout decides how it
3639− // combines with the lines under it.
3640− let mut children = Vec::new();
3641− let mut argument = None;
3642− let leading = kind.arg().attributes();
3644− Some(text) if !leading.is_empty() => {
3645− let (token, rest) = text.split_leading();
3648− .find(|a| a.html && leading.contains(&a.key.as_str()))
3649− .map(|a| (a.key.clone(), a.value.clone().unwrap_or_default()));
3650− if let Some((key, value)) = given {
3651− // The attribute wins; the text is content, as if the
3652− // element had no leading argument
3653− ctx.push_once(leading_twice(&kind, &token, &key, &value, text, ctx));
3654− if !takes_no_text(&kind) {
3655− children.push(Node::Text(text_segments(text, ctx)));
3657− } else if let Some(d) = bad_leading_token(&kind, &token, &text.raw, ctx) {
3658− // Nothing is taken as the argument; the line is content
3660− if !takes_no_text(&kind) {
3661− children.push(Node::Text(text_segments(text, ctx)));
3664− let column = Some(token.span.column);
3665− if let Some(d) = text_as_url(&kind, &token, ctx) {
3669− ctx.fill_value(&token.raw, text.span.line, column, Sink::Text)
3672− if let Some(rest) = rest {
3673− if let Some(d) = chain_after_argument(&kind, &token.raw, &rest, ctx) {
3676− if takes_no_text(&kind) {
3677− let d = after_the_leading_argument(&kind, &token.raw, &rest);
3678− let d = at_attribute(d, Some(rest.span.column), ctx);
3681− children.push(Node::Text(text_segments(&rest, ctx)));
3686− Some(text) if matches!(kind, ElementKind::Slot(_)) => {
3688− Some(ctx.interpolate_text(&text.raw, text.span.line, Some(text.span.column)));
3690− Some(text) => children.push(Node::Text(text_segments(text, ctx))),
3691− // `@link [href=/about]`: the attribute is the leading argument, so
3692− // both forms compile the same (`@image [src=a.svg, inline]`). Not
3693− // for `@source`, whose attribute depends on where it is.
3694− None if leading.len() == 1 => {
3695− if let Some(i) = attrs.iter().position(|a| a.html && a.key == leading[0]) {
3696− argument = Some(attrs.remove(i).value.unwrap_or_default());
3702− // For @slot, the argument is the slot name
3703− let kind = if let ElementKind::Slot(_) = kind {
3704− ElementKind::Slot(argument.clone().unwrap_or_default())
3719−/// Whether `node` or a line inside it calls `@name` outside any `@if`
3720−/// (in a chain, or inline in text).
3721−fn calls_unguarded(node: &syntax::Node, name: &str) -> bool {
3722− if node.is_directive("if") || node.is_directive("else") {
3725− let text_calls = |text: &syntax::Text| {
3728− .any(|s| matches!(s, Segment::Inline(inline) if inline.head.name == name))
3730− let here = match &node.kind {
3731− NodeKind::Element(element) => {
3732− element.chain.iter().any(|head| head.name == name)
3733− || element.text.as_ref().is_some_and(text_calls)
3735− NodeKind::Text(text) => text_calls(text),
3741− .any(|child| calls_unguarded(child, name))
3744−/// `@td [padding 8] @children`: `@children` and `@slot NAME` mark where a
3745−/// call's content goes only on a line of their own; after an element's
3746−/// attributes, or in a verbatim body, they are text.
3747−fn marker_in_text(node: &syntax::Node) -> Option<Diagnostic> {
3748− let is_marker = |text: &str| {
3749− let text = text.trim();
3750− text == "@children" || text == "@slot" || text.starts_with("@slot ")
3752− let mut line = node.span.line;
3753− let mut source = written_line(node);
3754− let (marker, message) = match &node.kind {
3755− NodeKind::Element(element) => {
3756− let text = element.text.as_ref()?;
3757− if !is_marker(&text.raw) {
3760− let name = &element.chain.last()?.name;
3761− let marker = text.raw.trim().to_string();
3762− let message = format!(
3763− "`{marker}` after @{name}'s attributes is text: it marks where a call's content \
3764− goes only on a line of its own, so write it on the next line, indented under \
3769− NodeKind::Verbatim(verbatim) if verbatim.escaped => {
3770− let (i, written) = verbatim
3774− .find(|(_, l)| is_marker(l))?;
3775− let marker = written.trim().to_string();
3777− source = written.to_string();
3778− let message = format!(
3779− "`{marker}` in a verbatim body is text: the body is written as it is, so it can't \
3780− hold a call's content (pass the text as a parameter instead)"
3787− Diagnostic::error(code::MISPLACED_SLOT, line, message)
3793−/// A first word that can't be a leading argument: an inline element
3794−/// (`@link {@b x} y`), or a quote that isn't closed (`@link "a b`).
3795−fn bad_leading_token(
3796− kind: &ElementKind,
3797− token: &syntax::Arg,
3799− ctx: &ParseContext,
3800−) -> Option<Diagnostic> {
3801− let what = leading_name(kind);
3802− let name = kind.name();
3803− let message = if token.raw.starts_with("{@") {
3805− "@{0} takes its {1} first, before any text: write `@{0} VALUE {2}`, or give it as \
3811− } else if token.raw.starts_with('"') && syntax::quoted_string(&token.raw).is_none() {
3813− "@{}'s {} starts with a `\"` that isn't closed: close it (`\"...\"`), or write \
3814− `\\\"` for a quote in the value",
3820− let d = Diagnostic::error(code::UNEXPECTED_ARGUMENT, token.span.line, message)
3821− .subject(token.raw.clone());
3822− Some(at_attribute(d, Some(token.span.column), ctx))
3825−/// A first word taken as a URL that reads as text: a word with a capital
3826−/// and nothing a URL or a file name has, as in `@link [hx-get=/panel] Open
3827−/// panel`, whose href would be `Open`. It still is (a relative URL can be
3828−/// such a word), with a warning.
3829−fn text_as_url(kind: &ElementKind, token: &syntax::Arg, ctx: &ParseContext) -> Option<Diagnostic> {
3830− const URLS: &[&str] = &["href", "src", "srcset", "action", "data"];
3831− let word = token.raw.as_str();
3832− let reads_as_text = word.starts_with(char::is_uppercase)
3833− && !word.contains([
3834− '/', '.', ':', '#', '?', '=', '&', '%', '~', '$', '{', '\\', '"',
3836− if !reads_as_text || !kind.arg().attributes().iter().any(|a| URLS.contains(a)) {
3839− let name = kind.name();
3840− let attr = leading_name(kind);
3841− let text = if takes_no_text(kind) {
3844− format!(": write the {attr} before the text, or put the text on the lines under it")
3846− let message = format!(
3847− "@{name} takes '{word}', its first word, as its {attr}{text}. A relative URL that \
3848− starts with a capital is written `./{word}`"
3850− let d = Diagnostic::warning(code::TEXT_AS_URL, token.span.line, message).subject(word);
3851− Some(at_attribute(d, Some(token.span.column), ctx))
3854−/// `@link /a > @image logo.png`: a `>` chains only after an element's
3855−/// name or its `[attributes]`, so after a leading argument it is text.
3856−/// Said when what follows names an element or a function.
3857−fn chain_after_argument(
3858− kind: &ElementKind,
3860− rest: &syntax::Text,
3861− ctx: &ParseContext,
3862−) -> Option<Diagnostic> {
3863− let after = rest.raw.strip_prefix('>')?;
3864− let name_start = after.trim_start().strip_prefix('@')?;
3865− if after.len() == after.trim_start().len() {
3868− let name: String = name_start
3870− .take_while(|c| c.is_ascii_alphanumeric() || *c == '-')
3872− if ElementKind::from_name(&name).is_none() && ctx.env.function(&name).is_none() {
3875− let attr = leading_name(kind);
3876− let d = Diagnostic::warning(
3877− code::UNEXPECTED_ARGUMENT,
3880− "`{}` after @{}'s {} is text, not a chain: `>` chains after an element's name or \
3881− its [attributes], so write `@{} [{}={}] {}`",
3882− rest.raw.trim_end(),
3888− rest.raw.trim_end()
3891− .subject(rest.raw.trim_end());
3892− Some(at_attribute(d, Some(rest.span.column), ctx))
3895−/// A leading argument given twice, as the first token and as its
3896−/// attribute: `@link [href=/a] About`.
3898− kind: &ElementKind,
3899− token: &syntax::Arg,
3902− text: &syntax::Text,
3903− ctx: &ParseContext,
3905− let name = kind.name();
3906− let what = leading_name(kind);
3907− // The value as one token: quoted when it is empty or has a space in it
3908− let value = if !value.is_empty() && syntax::leading_token_len(value) == value.len() {
3911− format!("\"{}\"", value.replace('\\', "\\\\").replace('"', "\\\""))
3913− let written = if takes_no_text(kind) {
3914− format!("@{} {}", name, value)
3916− format!("@{} {} {}", name, value, text.raw)
3918− let d = Diagnostic::error(
3919− code::DUPLICATE_ATTRIBUTE,
3922− "@{} takes its first word '{}' as its {}, and it also has {}=: give it once, \
3924− name, token.raw, what, key, written
3927− .subject(token.raw.clone());
3928− at_attribute(d, Some(token.span.column), ctx)
3931−/// The attribute an element's leading argument fills, for messages.
3932−fn leading_name(kind: &ElementKind) -> &'static str {
3934− TagArg::Source => "srcset in @picture or src elsewhere",
3935− arg => arg.attribute(false).unwrap_or("argument"),
3939−/// Whether text after an element's leading argument has nowhere to go:
3940−/// an element without content (`@image`, `@source`, ...), or `@optgroup`,
3941−/// which holds only `@option` lines, so `@optgroup Citrus fruits` would
3942−/// otherwise make `Citrus` the label and drop `fruits`.
3943−fn takes_no_text(kind: &ElementKind) -> bool {
3944− kind.layout() == Layout::Void || kind.is_tag("optgroup")
3947−/// Text after the leading argument of an element without content:
3948−/// `@image logo.png Our logo`.
3949−fn after_the_leading_argument(kind: &ElementKind, token: &str, rest: &syntax::Text) -> Diagnostic {
3950− let name = kind.name();
3951− let attr = leading_name(kind);
3952− let alt = if matches!(kind, ElementKind::Image) || kind.is_tag("area") {
3953− " For a text alternative, write `alt=...`."
3957− let holds = if kind.layout() == Layout::Void {
3958− "it has no content"
3960− "it holds only the elements on the lines under it"
3962− let bare = syntax::quoted_string(token).unwrap_or(token);
3964− code::UNEXPECTED_ARGUMENT,
3967− "@{0} takes one word after its attributes, its {1} ('{2}'), and {5}, so '{3}' \
3968− would go nowhere. A value with a space in it is quoted: `\"{6} {3}\"`.{4}",
3969− name, attr, token, rest.raw, alt, holds, bare
3972− .subject(rest.raw.clone())
3975−/// The element named `name`, or an "unknown element" error that suggests
3976−/// the closest element, directive or function.
3977−fn parse_element_kind(
3980− ctx: &mut ParseContext,
3981−) -> Result<ElementKind, ParseError> {
3982− if let Some(kind) = ElementKind::from_name(name) {
3985− // A known name in a place it can't go: say why instead of suggesting
3986− // the name itself.
3987− let misplaced = if crate::ast::directive(name).is_some() {
3989− "unknown element @{}: @{} is a directive, which goes at the start of its own line",
3992− } else if ctx.env.bundle(name).is_some() {
3994− "unknown element @{}: '{}' is an attribute bundle, used as `[${}]` \
3995− (a function is defined with `@let @{}`)",
3996− name, name, name, name
3998− } else if ctx.env.value(name).is_some() {
4000− "unknown element @{}: '{}' is a value, used as `${}` \
4001− (a function is defined with `@let @{}`)",
4002− name, name, name, name
4004− } else if ctx.namespace.contains(name) {
4005− ctx.used_functions.insert(name.to_string());
4007− "unknown element @{}: the function @{} isn't visible here. A definition is \
4008− visible from its line to the end of its block, and a function's body sees what \
4009− is defined above the function, so define @{} above this line, outside the block \
4013− } else if matches!(name, "svg" | "math" | "template") {
4015− "unknown element @{}: htmlang doesn't write <{}>; put its markup in the page with \
4020− " (or an SVG file with `@image [inline] file.svg`)"
4028− if let Some(message) = misplaced {
4029− return Err(Diagnostic::error(code::UNKNOWN_ELEMENT, line_num, message).subject(name));
4031− let all_known: Vec<&str> = ElementKind::all_names()
4032− .chain(DIRECTIVES.iter().map(|d| d.name))
4034− // An HTML element htmlang writes under its own name (`@a` is `@link`).
4035− let written_otherwise = crate::ast::HTML_NAMES_WRITTEN_OTHERWISE
4037− .find(|(html, _)| *html == name)
4038− .map(|(_, htmlang)| *htmlang);
4039− let closest = written_otherwise.or_else(|| suggest_closest(name, &all_known));
4040− let mut message = match (closest, written_otherwise) {
4041− (Some(closest), Some(_)) => format!(
4042− "unknown element @{}, did you mean @{}? (@{} writes <{}>)",
4043− name, closest, closest, name
4045− (Some(closest), None) => format!("unknown element @{}, did you mean @{}?", name, closest),
4046− (None, _) => format!("unknown element @{}", name),
4048− let function = suggest_fn_name(name, ctx);
4049− if let Some(function) = &function {
4050− message = format!("{}, or did you mean @{}?", message, function);
4052− Err(Diagnostic::error(code::UNKNOWN_ELEMENT, line_num, message)
4054− .suggest(closest.map(str::to_string).or(function)))
4057−/// Format include/import stack as a readable chain for error messages.
4058−fn format_include_chain(stack: &[PathBuf]) -> String {
4063− .unwrap_or_default()
4067− .collect::<Vec<_>>()
4071−/// Levenshtein distance with a rolling two-row buffer (O(min(a,b)) memory) and an
4072−/// early-exit cutoff: if every cell in a row exceeds `cutoff`, no further cell can
4073−/// be <= `cutoff`, so we return `cutoff + 1` immediately. Used for typo-suggestion
4074−/// hot paths where we only care about distances <= 2.
4075−fn levenshtein_bounded(a: &[char], b: &[char], cutoff: usize) -> usize {
4076− let (a, b) = if a.len() > b.len() { (b, a) } else { (a, b) };
4077− if b.len() - a.len() > cutoff {
4084− let mut prev: Vec<usize> = (0..=a.len()).collect();
4085− let mut curr: Vec<usize> = vec![0; a.len() + 1];
4087− for (j, &bc) in b.iter().enumerate() {
4089− let mut row_min = curr[0];
4090− for (i, &ac) in a.iter().enumerate() {
4091− let cost = if ac == bc { 0 } else { 1 };
4092− curr[i + 1] = (prev[i + 1] + 1).min(curr[i] + 1).min(prev[i] + cost);
4093− row_min = row_min.min(curr[i + 1]);
4095− if row_min > cutoff {
4098− std::mem::swap(&mut prev, &mut curr);
4103−fn suggest_closest<'a>(input: &str, candidates: &[&'a str]) -> Option<&'a str> {
4104− let input_chars: Vec<char> = input.chars().collect();
4105− let max_allowed = 2usize.min(input_chars.len().saturating_sub(1));
4106− let mut best = None;
4107− let mut best_dist = usize::MAX;
4108− for &candidate in candidates {
4109− // Cheap length-based prune before allocating chars.
4110− let clen = candidate.chars().count();
4111− let diff = clen.abs_diff(input_chars.len());
4112− if diff > max_allowed {
4115− let cand_chars: Vec<char> = candidate.chars().collect();
4116− let dist = levenshtein_bounded(&input_chars, &cand_chars, max_allowed);
4117− if dist < best_dist && dist <= max_allowed {
4119− best = Some(candidate);
4125−/// Suggest the closest user-defined function name for typos, from the
4126−/// functions defined so far and those defined anywhere in the file.
4127−fn suggest_fn_name(input: &str, ctx: &ParseContext) -> Option<String> {
4128− let input_chars: Vec<char> = input.chars().collect();
4129− let max_allowed = 2usize.min(input_chars.len().saturating_sub(1));
4130− let mut best: Option<(usize, &String)> = None;
4131− let visible: Vec<&String> = ctx.defined_functions.keys().collect();
4132− for name in visible.into_iter().chain(ctx.namespace.iter()) {
4133− let nlen = name.chars().count();
4134− if nlen.abs_diff(input_chars.len()) > max_allowed {
4137− let name_chars: Vec<char> = name.chars().collect();
4138− let dist = levenshtein_bounded(&input_chars, &name_chars, max_allowed);
4139− if dist <= max_allowed && best.is_none_or(|b| (dist, name) < b) {
4140− best = Some((dist, name));
4143− best.map(|(_, name)| name.clone())
4146−/// Suggest the closest variable name for undefined `$var` references.
4147−fn suggest_var_name(input: &str, vars: &[&str]) -> Option<String> {
4148− let input_chars: Vec<char> = input.chars().collect();
4149− let max_allowed = 2usize.min(input_chars.len().saturating_sub(1));
4150− let mut best: Option<String> = None;
4151− let mut best_dist = usize::MAX;
4152− let mut vars = vars.to_vec();
4153− // The same answer every time, whatever the order of the names
4154− vars.sort_unstable();
4156− let nlen = name.chars().count();
4157− if nlen.abs_diff(input_chars.len()) > max_allowed {
4160− let name_chars: Vec<char> = name.chars().collect();
4161− let dist = levenshtein_bounded(&input_chars, &name_chars, max_allowed);
4162− if dist < best_dist && dist <= max_allowed {
4164− best = Some(name.to_string());
4170−// ---------------------------------------------------------------------------
4171−// Attribute parsing
4172−// ---------------------------------------------------------------------------
4174−/// The quoted strings of a CSS value, without their quotes.
4175−fn css_strings(value: &str) -> Vec<&str> {
4176− let mut strings = Vec::new();
4177− let mut start = None;
4178− let mut escaped = false;
4179− for (i, c) in value.char_indices() {
4181− _ if escaped => escaped = false,
4182− ('\\', Some(_)) => escaped = true,
4183− ('"', None) => start = Some(i + 1),
4184− ('"', Some(from)) => {
4185− strings.push(&value[from..i]);
4194−/// An `if(...)` in a CSS value that isn't CSS's if(): CSS writes each
4195−/// branch `CONDITION: VALUE`, so an if() without a `:` is something else.
4196−/// Quoted CSS strings are text, not calls.
4197−fn not_css_if(value: &str) -> Option<&str> {
4198− let mut quote = None;
4199− let mut prev = None;
4200− let mut chars = value.char_indices();
4201− while let Some((at, c)) = chars.next() {
4203− Some(_) if c == '\\' => {
4206− Some(q) if c == q => quote = None,
4208− None if matches!(c, '"' | '\'') => quote = Some(c),
4211− prev.is_some_and(|p: char| p.is_alphanumeric() || matches!(p, '-' | '_'));
4212− if !word_before && value[at..].starts_with("if(") {
4214− let close = value[at + 2..].char_indices().find_map(|(i, c)| {
4220− (depth == 0).then_some(at + 2 + i)
4222− let end = close.map_or(value.len(), |c| c + 1);
4223− if !value[at + 3..end].contains(':') {
4224− return Some(&value[at..end]);
4234−/// Why a CSS value can't be written into a rule as it is, whatever it
4235−/// means: a `;` (outside parentheses, where CSS's own `if()` uses it), a
4236−/// `{` or a `}` would end the declaration or the rule, and an unclosed
4237−/// quote or parenthesis would run on into the rules after it. Quoted
4238−/// strings are text, and a backslash escapes the character after it, as
4239−/// in CSS. A `</style` anywhere, even in a string, would end the page's
4240−/// `<style>` element and start HTML.
4241−fn css_breakout(value: &str) -> Option<&'static str> {
4242− if value.to_ascii_lowercase().contains("</style") {
4243− return Some("a `</style`, which would end the page's style element");
4245− let mut quote = None;
4246− let mut depth = 0usize;
4247− let mut chars = value.chars();
4248− while let Some(c) = chars.next() {
4253− (Some(q), c) if c == q => quote = None,
4255− (None, '"' | '\'') => quote = Some(c),
4256− (None, '(') => depth += 1,
4257− (None, ')') if depth == 0 => return Some("a `)` that closes nothing"),
4258− (None, ')') => depth -= 1,
4259− (None, ';') if depth == 0 => return Some("a `;`, which would end the declaration"),
4260− (None, '{' | '}') => return Some("a `{` or `}`, which would end the CSS rule"),
4264− match (quote, depth) {
4265− (Some('"'), _) => Some("a `\"` that isn't closed"),
4266− (Some(_), _) => Some("a `'` that isn't closed"),
4268− (None, _) => Some("a `(` that isn't closed"),
4272−/// The hex colors of a CSS value that don't have 3, 4, 6 or 8 hex
4273−/// digits. A `#` word in a CSS value is a color, except inside `url(...)`
4274−/// and quoted strings.
4275−fn bad_hex_colors(value: &str) -> Vec<&str> {
4276− let mut bad = Vec::new();
4277− let mut quote = None;
4278− let mut in_url = 0usize;
4279− let mut depth = 0usize;
4280− let mut chars = value.char_indices().peekable();
4281− while let Some((at, c)) = chars.next() {
4286− (Some(q), c) if c == q => quote = None,
4288− (None, '"' | '\'') => quote = Some(c),
4291− if value[..at].ends_with("url") && in_url == 0 {
4296− if in_url == depth {
4299− depth = depth.saturating_sub(1);
4301− (None, '#') if in_url == 0 => {
4302− let end = value[at + 1..]
4303− .find(|c: char| !(c.is_alphanumeric() || c == '-' || c == '_'))
4304− .map_or(value.len(), |n| at + 1 + n);
4305− let hex = &value[at + 1..end];
4306− if !(matches!(hex.len(), 3 | 4 | 6 | 8)
4307− && hex.chars().all(|c| c.is_ascii_hexdigit()))
4309− bad.push(&value[at..end]);
4318−/// A diagnostic about an attribute, with its column and source line when
4319−/// it is on the line being evaluated.
4320−fn at_attribute(diagnostic: Diagnostic, column: Option<usize>, ctx: &ParseContext) -> Diagnostic {
4321− match (&ctx.current_source, column) {
4322− ((current, Some(text)), Some(column)) if *current == diagnostic.line => {
4323− diagnostic.column(column).source(text.clone())
4329−/// Check a style's value. Values go to the CSS as written, so only what
4330−/// can't be wrong in any CSS is checked: a value that would break out of
4331−/// its rule is an error (and it is left out); a hex color without 3, 4, 6
4332−/// or 8 digits, an `if()` that isn't CSS's and a quoted font stack are
4333−/// warnings. Returns whether the value can be written.
4338− column: Option<usize>,
4339− ctx: &mut ParseContext,
4341− let Some(value) = &attr.value else {
4344− if let Some(reason) = css_breakout(value) {
4345− let diagnostic = Diagnostic::error(
4346− code::INVALID_VALUE,
4349− "the value of '{}' has {}: `{}` can't be written into the page's CSS",
4350− attr.key, reason, value
4353− .subject(value.as_str());
4354− ctx.diagnostics.push(at_attribute(diagnostic, column, ctx));
4357− if crate::vocab::is_custom_property(base) {
4361− let warn = |ctx: &mut ParseContext, diagnostic: Diagnostic| {
4362− let diagnostic = at_attribute(diagnostic, column, ctx);
4363− ctx.diagnostics.push(diagnostic);
4365− // In CSS, a quoted font-family is one family, commas and all
4366− if base == "font-family"
4367− && let Some(family) = css_strings(value).into_iter().find(|s| s.contains(','))
4372− .collect::<Vec<_>>()
4376− Diagnostic::warning(
4377− code::INVALID_VALUE,
4380− "font-family \"{}\" is one family, whose name has a comma in it: \
4381− for a font stack, write `font-family {}`",
4385− .subject(format!("\"{}\"", family))
4386− .suggest(Some(stack)),
4389− if let Some(call) = not_css_if(value) {
4392− Diagnostic::warning(
4393− code::INVALID_VALUE,
4396− "'{}' is not CSS's if(), whose branches are written \
4397− `if(CONDITION: VALUE; else: VALUE)`",
4404− for color in bad_hex_colors(value) {
4407− Diagnostic::warning(
4408− code::INVALID_COLOR,
4411− "invalid hex color '{}': a hex color has 3, 4, 6 or 8 hex digits",
4421−/// An unknown prefix: the message, the text it is about, and what to write
4422−/// instead, when something is close enough.
4423−struct PrefixProblem {
4426− suggestion: Option<String>,
4429−/// What is wrong with the prefix `rest` starts with, when the known
4430−/// prefixes are already split off it and what is left still starts with
4431−/// one: a word and a `:` (`hovr:`), or a word and a parenthesised argument
4432−/// and a `:` (`nth-chld(2):`). Selector prefixes are CSS's pseudo-classes
4433−/// and pseudo-elements under their CSS names, so an unknown one gets the
4434−/// closest name as a suggestion. Only names with the same first letter are
4435−/// suggested: `odd:` is two edits from `md:`, which it doesn't mean.
4436−fn unknown_prefix(rest: &str) -> Option<PrefixProblem> {
4437− use crate::vocab::{self, Pseudo};
4438− let name_len = rest.find(|c: char| !(c.is_ascii_alphanumeric() || c == '-'))?;
4439− let name = &rest[..name_len];
4440− if name.is_empty() {
4443− if rest[name_len..].starts_with('(') {
4444− // `name(...):`: a pseudo-class with an argument
4445− let close = vocab::closing_paren(rest, name_len)?;
4446− if !rest[close + 1..].starts_with(':') {
4449− let written = &rest[..close + 2];
4450− if matches!(vocab::pseudo(name), Some(Pseudo::Class | Pseudo::Element)) {
4451− let bare = format!("{}:", name);
4452− return Some(PrefixProblem {
4454− "'{}': `{}` takes no argument: write `{}`",
4456− vocab::pseudo_selector(&bare).unwrap_or_default(),
4459− subject: written.to_string(),
4460− suggestion: Some(bare),
4463− let functional: Vec<&str> = vocab::functional_pseudos()
4465− .filter(|p| p.chars().next() == name.chars().next())
4467− let suggestion = suggest_closest(name, &functional)
4468− .filter(|&closest| closest != name)
4469− .map(|closest| format!("{}(", closest));
4470− let written = format!("{}(", name);
4471− let message = match &suggestion {
4472− Some(closest) => format!("unknown prefix '{}', did you mean '{}'?", written, closest),
4473− None => format!("unknown prefix '{}'", written),
4475− return Some(PrefixProblem {
4481− if !rest[name_len..].starts_with(':') {
4484− let written = &rest[..name_len + 1];
4485− // `has:`: its argument is missing
4486− if vocab::pseudo(name) == Some(Pseudo::Function) {
4487− return Some(PrefixProblem {
4489− "'{}': `:{}()` takes an argument, in parentheses, as in CSS: `{}(...):`",
4490− written, name, name
4492− subject: written.to_string(),
4496− let prefixes = vocab::all_prefixes();
4497− let candidates: Vec<&str> = prefixes
4499− .map(String::as_str)
4500− .filter(|p| p.chars().next() == written.chars().next())
4502− // The closest name that starts with the same letter (`hvoer:` →
4503− // `hover:`), else the first that starts with the word written and a `-`
4504− // (`first:` → `first-child:`)
4505− let suggestion = suggest_closest(written, &candidates)
4507− let longer = format!("{}-", name);
4508− candidates.iter().copied().find(|p| p.starts_with(&longer))
4510− .filter(|&closest| closest != written)
4511− .map(str::to_string);
4512− let message = match &suggestion {
4513− Some(closest) => format!("unknown prefix '{}', did you mean '{}'?", written, closest),
4514− None => format!("unknown prefix '{}'", written),
4516− Some(PrefixProblem {
4518− subject: written.to_string(),
4523−/// Check an attribute's element prefix (`@td:padding 8`), when it has one:
4524−/// it names a built-in element that has an HTML tag of its own (not a
4525−/// function, and not `@el`, whose `<div>` other elements write too), there
4526−/// is one, not with `children:`, and what it styles is a CSS property, not
4527−/// one of htmlang's words, which compile against each element's layout and
4528−/// its parent's. Returns false, after reporting, when the attribute can't
4530−fn check_element_prefixes(
4535− column: Option<usize>,
4536− ctx: &mut ParseContext,
4538− use crate::ast::ElementKind;
4540− let elements: Vec<&str> = prefixes
4543− .filter(|p| vocab::element_prefix(p).is_some())
4545− let Some(&prefix) = elements.first() else {
4548− let fail = |ctx: &mut ParseContext,
4549− code: &'static str,
4552− suggestion: Option<String>| {
4553− let diagnostic = Diagnostic::error(code, line, message)
4555− .suggest(suggestion);
4556− let diagnostic = at_attribute(diagnostic, column, ctx);
4557− ctx.diagnostics.push(diagnostic);
4560− let name = vocab::element_prefix(prefix).unwrap_or_default();
4561− if is_function(name, ctx) {
4564− code::INVALID_PREFIX,
4566− "'{}': @{} is a function, and `{}` would pick elements out by their HTML tag, \
4567− which a function doesn't have: style what @{} writes in its body, or pass it \
4569− attr.key, name, prefix, name
4575− match ElementKind::from_name(name) {
4577− let own: Vec<&str> = ElementKind::all_names()
4578− .filter(|n| ElementKind::from_name(n).is_some_and(|k| k.own_tag().is_some()))
4580− // An HTML name htmlang writes under another (`@a:` is `@link:`)
4581− let (written_otherwise, shared) = match crate::ast::HTML_NAMES_WRITTEN_OTHERWISE
4583− .find(|(html, _)| *html == name)
4585− Some((_, htmlang)) if own.contains(htmlang) => (Some(*htmlang), false),
4586− Some(_) => (None, true),
4587− None => (None, false),
4589− // `@each:`, `@markdown:`: a directive, which is no element
4590− if crate::ast::directive(name).is_some() {
4593− code::UNKNOWN_PREFIX,
4595− "unknown element @{} in '{}': @{} is a directive, and an element \
4596− prefix names an element with an HTML tag of its own, such as `@td:`",
4603− // `@div:`, `@span:`: several elements write it
4607− code::UNKNOWN_PREFIX,
4609− "unknown element @{} in '{}': htmlang writes <{}> for several \
4610− elements, so no element prefix picks it out",
4617− // A name with the same first letter first (`@tdd:` is `@td:`)
4618− let same_letter: Vec<&str> = own
4621− .filter(|n| n.chars().next() == name.chars().next())
4623− let closest = written_otherwise
4624− .or_else(|| suggest_closest(name, &same_letter))
4625− .or_else(|| suggest_closest(name, &own));
4626− let message = match (closest, written_otherwise) {
4627− (Some(closest), Some(_)) => format!(
4628− "unknown element @{} in '{}', did you mean '@{}:'? (@{} writes <{}>)",
4629− name, prefix, closest, closest, name
4631− (Some(closest), None) => format!(
4632− "unknown element @{} in '{}', did you mean '@{}:'?",
4633− name, prefix, closest
4635− (None, _) => format!("unknown element @{} in '{}'", name, prefix),
4637− let suggestion = closest.map(|c| format!("@{}:", c));
4638− fail(ctx, code::UNKNOWN_PREFIX, message, prefix, suggestion)
4640− Some(kind) if kind.own_tag().is_none() => {
4641− let reason = match kind.tag() {
4643− "@{} writes no element of its own, so there is nothing for `{}` to style",
4646− Some(_) if kind.is_verbatim() => {
4647− format!("@{} isn't shown, so there is nothing to style", name)
4649− Some("span") => format!(
4650− "@{} writes a <span>, as every line of text in a row or column does, so \
4651− `{}` can't pick it out",
4655− let others: Vec<String> = ElementKind::all_names()
4658− && ElementKind::from_name(n).and_then(|k| k.tag()) == Some(tag)
4660− .map(|n| format!("@{}", n))
4662− let others = match others.split_last() {
4663− Some((last, [])) => last.clone(),
4664− Some((last, rest)) => format!("{} and {}", rest.join(", "), last),
4665− None => String::new(),
4668− "@{} writes a <{}>, as {} do, so `{}` can't pick it out",
4669− name, tag, others, prefix
4675− code::INVALID_PREFIX,
4677− "'{}': {}. Give those elements their styles themselves, or a bundle \
4678− (`@let name [...]`, used as `[$name]`)",
4685− Some(_) if elements.len() > 1 => fail(
4687− code::INVALID_PREFIX,
4689− "'{}': a style takes one element prefix, which styles every such element \
4690− inside this one, at any depth",
4696− Some(_) if prefixes.contains(&vocab::CHILDREN) => fail(
4698− code::INVALID_PREFIX,
4700− "'{}': `children:` and `{}` each say which elements the style is for: write \
4707− Some(_) if vocab::is_htmlang_word(base, attr.value.as_deref()) => {
4708− let value = attr.value.as_deref().map(str::trim);
4709− let css = match (base, value) {
4710− ("spacing", _) => " (`gap`)",
4711− ("wrap", _) => " (`flex-wrap wrap`)",
4712− ("grid-cols", _) => " (`grid-template-columns`)",
4713− ("grid-rows", _) => " (`grid-template-rows`)",
4714− ("col-span", _) => " (`grid-column span N`)",
4715− ("row-span", _) => " (`grid-row span N`)",
4716− ("width", Some("fill")) => " (`flex 1` in a row, `width 100%` otherwise)",
4717− ("height", Some("fill")) => " (`flex 1` in a column, `height 100%` otherwise)",
4718− ("width", _) => " (`flex-shrink 0` in a row, `width fit-content` otherwise)",
4719− ("height", _) => " (`flex-shrink 0` in a column, `height fit-content` otherwise)",
4720− ("center-x", _) => " (`margin-inline auto`)",
4721− ("center-y", _) => " (`margin-block auto`)",
4724− let word = match value {
4725− Some(v) if matches!(base, "width" | "height") => format!("{} {}", base, v),
4726− _ => base.to_string(),
4730− code::INVALID_PREFIX,
4732− "'{}': `{}` is one of htmlang's layout words, which compile against each \
4733− element's layout and its parent's, and `{}` styles elements whose \
4734− parents it doesn't know: write `{}` on the elements themselves, or the \
4736− attr.key, word, prefix, word, css
4746−/// Check an attribute's prefixes: each is known, their selector prefixes
4747−/// read left to right with a pseudo-element (`before:`) last, the argument
4748−/// of `has(...)` or `nth-child(...)` can be written into the CSS, and a word that
4749−/// places an element in its parent (`width fill`, `center-x`, `align-*`)
4750−/// isn't under `children:`, whose styles go on the children. Media,
4751−/// container and width prefixes go anywhere. Returns false, after
4752−/// reporting, when the attribute can't be written.
4756− column: Option<usize>,
4757− ctx: &mut ParseContext,
4760− let (prefixes, base) = vocab::split_prefixes(&attr.key);
4762− |ctx: &mut ParseContext, message: String, subject: &str, suggestion: Option<String>| {
4763− let diagnostic = Diagnostic::error(code::INVALID_PREFIX, line, message)
4765− .suggest(suggestion);
4766− let diagnostic = at_attribute(diagnostic, column, ctx);
4767− ctx.diagnostics.push(diagnostic);
4771− if let Some(problem) = unknown_prefix(base) {
4772− let diagnostic = Diagnostic::error(code::UNKNOWN_PREFIX, line, problem.message)
4773− .subject(problem.subject)
4774− .suggest(problem.suggestion);
4775− let diagnostic = at_attribute(diagnostic, column, ctx);
4776− ctx.diagnostics.push(diagnostic);
4779− if !check_element_prefixes(attr, &prefixes, base, line, column, ctx) {
4782− // The argument of `has(...)` or `nth-child(...)` goes into the CSS as
4784− for prefix in &prefixes {
4785− if let Some(reason) = css_breakout(prefix.trim_end_matches(':')) {
4789− "the prefix '{}' has {}: it can't be written into the page's CSS",
4797− // `nth-child():` or `has( ):`: CSS has no pseudo-class with an empty
4799− let empty_argument = |prefix: &str| {
4801− .strip_suffix("):")
4802− .and_then(|p| p.split_once('('))
4803− .is_some_and(|(_, argument)| argument.trim().is_empty())
4805− if let Some(empty) = prefixes.iter().find(|p| empty_argument(p)) {
4809− "'{}': `:{}()` takes an argument between its parentheses, as in CSS",
4811− vocab::pseudo_name(empty)
4817− // A pseudo-element is the last selector prefix: CSS has no
4818− // `::before:hover`
4819− let selectors: Vec<&str> = prefixes
4822− .filter(|p| vocab::at_rule_rank(p).is_none())
4824− // Only one: an element has one `::before`, which has no `::after`
4825− let elements: Vec<&str> = selectors
4828− .filter(|p| vocab::is_pseudo_element(p))
4830− if elements.len() > 1 {
4834− "'{}': `{}` and `{}` each select a pseudo-element, and a style applies to one \
4836− attr.key, elements[0], elements[1]
4842− if let Some(at) = selectors.iter().position(|p| vocab::is_pseudo_element(p))
4843− && at + 1 < selectors.len()
4845− let element = selectors[at];
4846− // The same prefixes, with the pseudo-element moved after the other
4847− // selector prefixes
4848− let mut order: Vec<&str> = prefixes.iter().copied().filter(|p| *p != element).collect();
4849− let last_selector = order
4851− .rposition(|p| vocab::at_rule_rank(p).is_none())
4852− .map_or(order.len(), |i| i + 1);
4853− order.insert(last_selector, element);
4854− let fixed = format!("{}{}", order.concat(), base);
4858− "'{}': `{}` selects a pseudo-element, which comes after the other selector \
4859− prefixes, as in CSS: write `{}`",
4860− attr.key, element, fixed
4866− // Under `children:` the styles go on the children, whose parent is this
4867− // element: a word that places an element in its parent can't say where
4868− if prefixes.contains(&"children:") && vocab::places_in_parent(base, attr.value.as_deref()) {
4869− // The CSS of `fill` and `shrink` depends on the direction: along
4870− // it, they are flex properties
4871− let (word, css) = match (base, attr.value.as_deref().map(str::trim)) {
4872− ("width", Some("fill")) => (
4874− " (`children:flex 1` in a row, `children:width 100%` otherwise)",
4876− ("height", Some("fill")) => (
4878− " (`children:flex 1` in a column, `children:height 100%` otherwise)",
4880− ("width", Some(_)) => (
4882− " (`children:flex-shrink 0` in a row, `children:width fit-content` otherwise)",
4884− ("height", Some(_)) => (
4886− " (`children:flex-shrink 0` in a column, `children:height fit-content` \
4894− "'{}{}': `{}` places an element in its parent, and under `children:` that \
4895− parent is this element: write `{}` on the children themselves, or the CSS \
4900− .map_or(String::new(), |v| format!(" {}", v.trim())),
4912−/// Check an attribute written as a style or a flag (not `key=value`): its
4913−/// prefix, its name, and, for a style, its value. A name htmlang doesn't
4914−/// know but CSS could have (`corner-shape`) is passed to the CSS as written,
4915−/// with a warning; custom properties (`--brand`) and vendor-prefixed ones
4916−/// (`-webkit-...`) without one. Anything that can't be written into the
4917−/// page is an error; returns false then, and the attribute is left out.
4921− column: Option<usize>,
4922− before: Option<&Attribute>,
4923− ctx: &mut ParseContext,
4926− let (prefixes, base) = vocab::split_prefixes(&attr.key);
4927− let fail = |ctx: &mut ParseContext, code: &'static str, message: String, subject: &str| {
4928− let diagnostic = Diagnostic::error(code, line, message).subject(subject);
4929− let diagnostic = at_attribute(diagnostic, column, ctx);
4930− ctx.diagnostics.push(diagnostic);
4934− if !check_prefixes(attr, line, column, ctx) {
4937− let prefixed = !prefixes.is_empty();
4938− // `md:id=x`: `=` makes an HTML attribute, which has no states
4939− if prefixed && let Some((name, _)) = base.split_once('=') {
4942− code::INVALID_PREFIX,
4944− "'{}': a prefix applies to a style, and `{}=` is an HTML attribute",
4950− let Some(value) = &attr.value else {
4951− // `inline` puts a file into the page as it compiles, which no
4952− // state or media condition can undo
4953− if base == "inline" && prefixed {
4956− code::INVALID_PREFIX,
4958− "'{}': `inline` puts the image's file into the page, which can't depend \
4965− if vocab::HTMLANG_FLAGS.contains(&base) {
4968− if vocab::is_html_flag(base) {
4974− code::INVALID_PREFIX,
4976− "'{}': a prefix applies to a style, and '{}' is an HTML attribute",
4982− if vocab::is_style_attribute(base)
4983− || vocab::is_custom_property(base)
4984− || vocab::is_vendor_property(base)
4988− code::MISSING_VALUE,
4989− format!("'{}' needs a value: `{} VALUE`", attr.key, attr.key),
4993− if vocab::is_html_attribute(base) && !prefixed {
4996− code::HTML_ATTRIBUTE_FORM,
4998− "'{}' is an HTML attribute that isn't a flag: write `{}=VALUE`",
5004− return unknown_attribute(attr, base, line, column, before, true, ctx);
5007− if vocab::HTMLANG_FLAGS.contains(&base) {
5010− code::INVALID_VALUE,
5012− "'{}' is a flag and takes no value: write `{}` alone",
5018− if vocab::is_style_attribute(base)
5019− || vocab::is_custom_property(base)
5020− || vocab::is_vendor_property(base)
5022− return check_css_value(attr, base, line, column, ctx);
5024− if vocab::is_html_attribute(base) && !prefixed {
5025− let diagnostic = Diagnostic::error(
5026− code::HTML_ATTRIBUTE_FORM,
5029− "'{}' is an HTML attribute: write `{}={}`",
5030− attr.key, attr.key, value
5033− .subject(attr.key.as_str());
5034− let diagnostic = at_attribute(diagnostic, column, ctx);
5035− ctx.diagnostics.push(diagnostic);
5038− let passes = vocab::is_property_name(base);
5039− unknown_attribute(attr, base, line, column, before, !passes, ctx)
5040− && check_css_value(attr, base, line, column, ctx)
5043−/// Whether an attribute of a bundle could pass a parameter to a function
5044−/// it is spliced into (`@let t [title Hello]`): a name without a prefix
5045−/// that isn't a style or a flag. Such a name is checked where the bundle is
5047−fn could_be_parameter(attr: &Attribute) -> bool {
5049− let key = attr.key.as_str();
5051− attr.value.is_none() && (vocab::HTMLANG_FLAGS.contains(&key) || vocab::is_html_flag(key));
5054− && !vocab::is_style_attribute(key)
5055− && key.starts_with(|c: char| c.is_alphabetic())
5058− .all(|c| c.is_alphanumeric() || matches!(c, '-' | '_'))
5061−/// At a call, a name close to one of the function's parameters is a
5062−/// misspelled parameter, not an attribute for its root: report it, and
5063−/// return true (it is left out).
5064−fn misspelled_parameter(
5066− text_keys: &[String],
5068− column: Option<usize>,
5069− ctx: &mut ParseContext,
5071− if text_keys.is_empty() || !could_be_parameter(attr) {
5074− let params: Vec<&str> = text_keys.iter().map(String::as_str).collect();
5075− let Some(closest) = suggest_closest(&attr.key, ¶ms) else {
5078− let what = if ctx.in_page {
5083− let diagnostic = Diagnostic::error(
5084− code::UNKNOWN_ATTRIBUTE,
5087− "unknown {} '{}', did you mean '{}'?",
5088− what, attr.key, closest
5091− .subject(attr.key.as_str())
5092− .suggest(Some(closest));
5093− let diagnostic = at_attribute(diagnostic, column, ctx);
5094− ctx.diagnostics.push(diagnostic);
5098−/// An attribute name htmlang doesn't know. A style whose name CSS could
5099−/// have goes to the CSS as written, with a warning; anything else (a flag,
5100−/// a name that isn't a word) is an error. Returns whether it is kept.
5101−fn unknown_attribute(
5105− column: Option<usize>,
5106− before: Option<&Attribute>,
5108− ctx: &mut ParseContext,
5110− // `@td padding 8`: an element prefix without its colon
5111− if let Some(name) = base.strip_prefix('@')
5112− && crate::ast::ElementKind::from_name(name).is_some()
5114− let example = match attr.value.as_deref() {
5115− Some(value) => format!("{}:{}", attr.key, value.trim()),
5116− None => format!("{}:padding 8", attr.key),
5118− let diagnostic = Diagnostic::error(
5119− code::UNKNOWN_ATTRIBUTE,
5122− "unknown attribute '{}': an element prefix ends in a colon, as in `{}`",
5127− let diagnostic = at_attribute(diagnostic, column, ctx);
5128− ctx.diagnostics.push(diagnostic);
5131− // `[card]` where `card` is a bundle: it is used as `$card`
5132− if attr.value.is_none() && ctx.env.bundle(base).is_some() && base == attr.key {
5133− ctx.used_defines.insert(base.to_string());
5134− let diagnostic = Diagnostic::error(
5135− code::UNKNOWN_ATTRIBUTE,
5138− "unknown attribute '{}': '{}' is an attribute bundle, used as `${}`",
5143− .suggest(Some(format!("${}", base)));
5144− let diagnostic = at_attribute(diagnostic, column, ctx);
5145− ctx.diagnostics.push(diagnostic);
5148− // `hover:title x`: an HTML attribute's name is not a suggestion for
5151− suggest_closest(base, &crate::vocab::all_attributes()).filter(|&closest| closest != base);
5152− // `hx-trigger=load, every 2s`: right after a `key=value`, a name that
5153− // isn't close to one htmlang knows is the rest of that value, which
5154− // the comma ended. It is left out.
5155− let cut = before.filter(|b| b.html && b.value.is_some());
5156− let rest = match &attr.value {
5157− Some(value) => format!("{} {}", attr.key, value),
5158− None => attr.key.clone(),
5160− let joined = cut.map(|cut| {
5161− let value = cut.value.as_deref().unwrap_or("");
5163− format!("{}={}", cut.key, value),
5164− format!("{}={}\\, {}", cut.key, value, rest),
5167− if let (Some((cut, joined)), None) = (&joined, suggestion) {
5168− let diagnostic = Diagnostic::error(
5172− "unknown attribute '{}' after `{}`: if '{}' is the rest of its value, the comma \
5173− ended it. To keep a comma in a value, write `\\,`: `{}`",
5174− base, cut, rest, joined
5178− let diagnostic = at_attribute(diagnostic, column, ctx);
5179− ctx.diagnostics.push(diagnostic);
5182− let mut message = match (&suggestion, error) {
5183− (Some(closest), true) => {
5185− "unknown attribute '{}', did you mean '{}'?",
5189− (None, true) => format!("unknown attribute '{}'", attr.key),
5190− (Some(closest), false) => format!(
5191− "unknown CSS property '{}', did you mean '{}'? It is written to the CSS as it is",
5194− (None, false) => format!(
5195− "unknown CSS property '{}': it is written to the CSS as it is",
5199− // `box-shadow 0 1px red, 0 2px blue` or `font-family Inter,
5200− // sans-serif`: the comma ended the attribute, and the rest of the
5201− // value became one
5202− let rest_of_a_value = !base.starts_with(|c: char| c.is_ascii_alphabetic() || c == '-')
5203− || (suggestion.is_none() && attr.value.is_none() && before.is_some());
5204− if joined.is_some() || (rest_of_a_value && error) {
5205− if !message.ends_with('?') {
5209− Some((cut, joined)) => message.push_str(&format!(
5210− " If it is the rest of `{}`, the comma ended it: write `{}`",
5214− .push_str(" A comma separates attributes: to keep one in a value, write `\\,`"),
5217− let severity = if error {
5222− let diagnostic = Diagnostic::new(code::UNKNOWN_ATTRIBUTE, severity, line, message)
5224− .suggest(suggestion);
5225− let diagnostic = at_attribute(diagnostic, column, ctx);
5226− ctx.diagnostics.push(diagnostic);
5230−/// Evaluate the attributes of a list: bundles are spliced in, `if()`
5231−/// chooses, and variables fill values. A variable fills only the value it
5232−/// is written in: attributes come from bundles, never from text. With
5233−/// `validate`, unknown names and invalid values are reported. `text_keys`
5234−/// are a called function's parameters: their values are text rather than
5235−/// CSS, and they aren't checked as attributes.
5237− tokens: &[syntax::Attr],
5239− ctx: &mut ParseContext,
5241− text_keys: &[String],
5242−) -> Vec<Attribute> {
5243− parse_attrs(tokens, line_num, ctx, validate, text_keys)
5245− .map(|(attr, _)| attr)
5249−/// [`parse_attr_list`], with the value of each attribute whose key is one
5250−/// of `text_keys` (a call's parameters) as a value with its type (see
5251−/// [`ParseContext::slot_value`]), so a parameter can get a list or a
5254− tokens: &[syntax::Attr],
5256− ctx: &mut ParseContext,
5258− text_keys: &[String],
5259−) -> Vec<(Attribute, Option<Value>)> {
5260− let mut read = ReadAttrs::default();
5261− read_attrs(tokens, "", line_num, ctx, validate, text_keys, &mut read);
5265−/// The attributes of a list read so far, and the keys written (for the
5266−/// duplicate check).
5269− attrs: Vec<(Attribute, Option<Value>)>,
5270− seen_keys: Vec<(String, bool)>,
5273−/// [`parse_attrs`] for the attributes of `tokens`, each under the prefixes
5274−/// `prefix` (`md:` for those of `md:[...]`), which distribute over a
5275−/// group, a bundle and the branch an `if()` takes. Only styles take a
5276−/// prefix, so an HTML attribute there is an error.
5278− tokens: &[syntax::Attr],
5281− ctx: &mut ParseContext,
5283− text_keys: &[String],
5284− out: &mut ReadAttrs,
5286− let mut chosen = Vec::new();
5297− for token in &chosen {
5298− let line = if token.span.line == 0 {
5303− let (key, value, html) = (token.key.clone(), token.value.clone(), token.html);
5304− let column = |at: usize| Some(token.span.column + at);
5306− // `md:[...]`, `md:$card`, `md:if(...)`: the prefixes apply to each
5307− // attribute there, and a prefix a parameter can't have
5308− if let Some(prefixed) = &token.prefixed {
5309− if let Some(inner) = group_prefix(token, prefixed, prefix, line, ctx) {
5311− prefixed.target.attrs(),
5323− // `$name` (or `${name}`) alone: an attribute bundle, spliced in
5324− let bundle = key.strip_prefix('$').filter(|_| value.is_none() && !html);
5325− let bundle = bundle.and_then(|after| match interp::reference(after, &ctx.env)? {
5326− (interp::Reference::Var(name), len) if len == after.len() => Some(name),
5329− if let Some(name) = bundle {
5330− if let Some(define_attrs) = ctx.env.bundle(&name).cloned() {
5331− ctx.used_defines.insert(name.clone());
5332− for attr in define_attrs.iter() {
5333− if !prefix.is_empty() {
5334− let prefixed = Attribute {
5335− key: format!("{}{}", prefix, attr.key),
5338− if prefixed_parameter(&prefixed, text_keys, line, column(0), validate, ctx)
5342− if let Some(attr) =
5343− prefixed_member(attr, prefix, &name, line, column(0), validate, ctx)
5345− out.attrs.push((attr, None));
5349− let attrs = &out.attrs;
5350− // Checked here, where it is either a parameter or not
5351− let checked_here = validate
5353− && could_be_parameter(attr)
5354− && !text_keys.contains(&attr.key);
5356− && (misspelled_parameter(attr, text_keys, line, column(0), ctx)
5357− || !check_attribute(
5361− attrs.last().map(|(a, _)| a),
5367− out.attrs.push((attr.clone(), None));
5370− not_a_bundle(&name, line, column(0), ctx);
5374− // A name never comes from a variable
5375− if key.contains('$') {
5376− track_var_refs(&key, &mut ctx.used_variables);
5377− ctx.diagnostics.push(
5379− code::ATTRIBUTE_FROM_VARIABLE,
5382− "'{}': an attribute's name can't come from a variable. A variable \
5383− fills a value (`padding $size`), and whole attributes come from a \
5384− bundle (`@let name [padding 8]`, used as `[$name]`)",
5388− .subject(key.as_str()),
5393− // Only a style has states: `md:[id=x]`, `md:id=x`
5394− if html && (!prefix.is_empty() || !crate::vocab::split_prefixes(&key).0.is_empty()) {
5395− let written = format!("{}{}", prefix, key);
5396− let (name, _) = crate::vocab::split_prefixes(&written);
5397− let diagnostic = Diagnostic::error(
5398− code::INVALID_PREFIX,
5401− "'{}=': a prefix applies to a style, and `{}=` is an HTML attribute, \
5402− which has no states",
5404− &written[name.concat().len()..]
5407− .subject(token.key.as_str());
5408− let diagnostic = at_attribute(diagnostic, column(0), ctx);
5409− ctx.diagnostics.push(diagnostic);
5412− let key = if prefix.is_empty() {
5415− format!("{}{}", prefix, key)
5418− // A value's variables are filled in. A style's value is CSS, where
5419− // quoted text keeps its quotes; an HTML attribute's (and a
5420− // parameter's) is text, where it loses them.
5421− let sink = if html || text_keys.contains(&key) {
5426− let mut filled = true;
5427− let mut quoted = None;
5428− let mut typed = None;
5429− let value = match value {
5431− // A parameter's value keeps its type
5432− Some(value) if !html && text_keys.contains(&key) => {
5433− let at = column(token.raw.len() - value.len());
5434− let (value, ok) = ctx.slot_value(&value, line, at);
5436− if let Value::Quoted(q) = &value {
5437− quoted = Some(q.clone());
5439− let text = value.to_string();
5440− typed = Some(value);
5444− let at = column(token.raw.len() - value.len());
5445− let (text, is_quoted, ok) = ctx.fill_value(&value, line, at, sink);
5447− quoted = is_quoted;
5451− let attr = Attribute {
5457− // A value that couldn't be filled in is already reported, and a
5458− // parameter's value is text for the function
5459− let validate = validate && filled && !text_keys.contains(&attr.key);
5461− // A duplicate is reported (compare the full key, so `border` and
5462− // `hover:border` differ, and the form, so `width=800` and
5463− // `width 200` do too), and the later one wins
5465− let seen = (normal_key(&attr.key), attr.html);
5466− if out.seen_keys.contains(&seen) {
5467− let written = if attr.html { "=" } else { "" };
5468− let message = format!(
5469− "duplicate attribute '{}{}': the later one wins",
5472− let diagnostic = Diagnostic::warning(code::DUPLICATE_ATTRIBUTE, line, message)
5473− .subject(attr.key.as_str());
5474− let diagnostic = at_attribute(diagnostic, column(0), ctx);
5475− ctx.diagnostics.push(diagnostic);
5477− out.seen_keys.push(seen);
5481− if validate && misspelled_parameter(&attr, text_keys, line, column(0), ctx) {
5484− if prefixed_parameter(&attr, text_keys, line, column(0), validate, ctx) {
5487− if validate && attr.html && attr.key == "class" {
5488− reserved_class(&attr, line, column(0), ctx);
5490− // `padding=4`: a style written as an HTML attribute, which the
5491− // browser ignores (`width=` and `height=` are real on some
5492− // elements, see `validate_tree`)
5495− && crate::vocab::is_style_attribute(&attr.key)
5496− && !crate::vocab::HTML_ATTRIBUTES.contains(&attr.key.as_str())
5498− let value = token.value.as_deref().unwrap_or("").trim();
5499− let diagnostic = Diagnostic::warning(
5500− code::HTML_ATTRIBUTE_FORM,
5503− "'{0}={1}' is an HTML attribute, but {0} is a style: write `{0} {1}`",
5507− .subject(token.raw.as_str())
5508− .suggest(Some(format!("{} {}", attr.key, value)));
5509− let diagnostic = at_attribute(diagnostic, column(0), ctx);
5510− ctx.diagnostics.push(diagnostic);
5513− // A style or a flag: its name is checked, and what can't be
5514− // written into the page is an error and left out
5515− let checked = validate && !attr.html && !(ctx.in_bundle && could_be_parameter(&attr));
5516− let before = out.attrs.last().map(|(a, _)| a);
5517− if checked && !check_attribute(&attr, line, column(0), before, ctx) {
5521− out.attrs.push((attr, typed));
5525−/// At a call, a parameter under prefixes (`md:title x`, `md:[title x]`):
5526−/// a parameter has one value, with no states, so it is reported (with
5527−/// `validate`) and left out; returns true then. A parameter named like a
5528−/// style (`color`) is a style under a prefix, for the root element.
5529−fn prefixed_parameter(
5531− text_keys: &[String],
5533− column: Option<usize>,
5535− ctx: &mut ParseContext,
5537− let (prefixes, name) = crate::vocab::split_prefixes(&attr.key);
5539− || prefixes.is_empty()
5540− || !text_keys.iter().any(|k| k == name)
5541− || crate::vocab::is_style_attribute(name)
5546− let what = if ctx.in_page {
5551− let diagnostic = Diagnostic::error(
5552− code::INVALID_PREFIX,
5555− "'{}': `{}` is {}, which has one value, and a prefix applies to a style, \
5557− attr.key, name, what
5560− .subject(attr.key.as_str());
5561− let diagnostic = at_attribute(diagnostic, column, ctx);
5562− ctx.diagnostics.push(diagnostic);
5567−/// The prefixes of a prefixed group, bundle or `if()` inside `outer` (the
5568−/// prefixes of the groups it is in), when they are all known; else the
5569−/// unknown one is reported. Text after a group's `]` is an error too.
5571− token: &syntax::Attr,
5572− prefixed: &syntax::Prefixed,
5575− ctx: &mut ParseContext,
5576−) -> Option<String> {
5577− let at = |ctx: &ParseContext, diagnostic: Diagnostic, span: syntax::Span| match &ctx
5580− (current, Some(text)) if span.line != 0 && *current == span.line => {
5581− diagnostic.column(span.column).source(text.clone())
5585− if let syntax::Branch::Group {
5586− trailing: Some(trailing),
5588− } = &prefixed.target
5590− let diagnostic = Diagnostic::error(
5591− code::UNEXPECTED_ARGUMENT,
5594− "'{}' after the `]` of `{}[...]`: the prefixes apply to the attributes in the \
5595− group, so it goes inside it",
5596− trailing.raw, prefixed.prefix
5599− .subject(trailing.raw.as_str());
5600− let diagnostic = at(ctx, diagnostic, trailing.span);
5601− ctx.push_once(diagnostic);
5603− let (known, rest) = crate::vocab::split_prefixes(&prefixed.prefix);
5604− if !rest.is_empty() {
5605− let problem = unknown_prefix(rest).unwrap_or_else(|| {
5606− let written = rest.split_inclusive(':').next().unwrap_or(rest);
5608− message: format!("unknown prefix '{}'", written),
5609− subject: written.to_string(),
5613− let diagnostic = Diagnostic::error(code::UNKNOWN_PREFIX, line, problem.message)
5614− .subject(problem.subject)
5615− .suggest(problem.suggestion);
5616− let diagnostic = at(ctx, diagnostic, token.span);
5617− ctx.push_once(diagnostic);
5620− Some(format!("{}{}", outer, known.concat()))
5623−/// An attribute of the bundle `bundle`, spliced in under `prefix`
5624−/// (`md:$card`): the same attribute with the prefixes in front, when it can
5625−/// take them. An HTML attribute can't; a style's prefixes are checked, as
5626−/// is a flag or a name that isn't a style (a bundle's parameter), which
5627−/// under a prefix are attributes like any other.
5633− column: Option<usize>,
5635− ctx: &mut ParseContext,
5636−) -> Option<Attribute> {
5637− let key = format!("{}{}", prefix, attr.key);
5640− let diagnostic = Diagnostic::error(
5641− code::INVALID_PREFIX,
5644− "'{}${}': the bundle has `{}=`, an HTML attribute, and a prefix applies to \
5645− styles, which have states",
5646− prefix, bundle, attr.key
5649− .subject(format!("{}${}", prefix, bundle));
5650− let diagnostic = at_attribute(diagnostic, column, ctx);
5651− ctx.diagnostics.push(diagnostic);
5655− let prefixed = Attribute {
5660− let fine = if attr.value.is_none() || could_be_parameter(attr) {
5661− check_attribute(&prefixed, line, column, None, ctx)
5663− check_prefixes(&prefixed, line, column, ctx)
5672−/// `class=hl-x`: the `hl-` prefix is htmlang's, for its generated classes,
5673−/// whose rules would then apply to the element too. It goes into the page
5674−/// as written, so this is a warning.
5675−fn reserved_class(attr: &Attribute, line: usize, column: Option<usize>, ctx: &mut ParseContext) {
5676− let classes = attr.value.as_deref().unwrap_or_default();
5677− for class in classes.split_whitespace() {
5678− if class.starts_with(crate::codegen::CLASS_PREFIX) {
5679− let diagnostic = Diagnostic::warning(
5680− code::INVALID_VALUE,
5683− "class '{}' starts with `{}`, which htmlang keeps for the classes it \
5684− generates, so their styles could apply to this element: give it \
5687− crate::codegen::CLASS_PREFIX
5691− let diagnostic = at_attribute(diagnostic, column, ctx);
5692− ctx.diagnostics.push(diagnostic);
5697−/// A style's key as the CSS reads it, for finding duplicates: its at-rule
5698−/// prefixes in one order (`dark:md:` is `md:dark:`), then its selector
5699−/// prefixes as written, whose order is the selector's.
5700−fn normal_key(key: &str) -> String {
5701− let (prefixes, name) = crate::vocab::split_prefixes(key);
5702− let mut at: Vec<(usize, &str)> = prefixes
5704− .filter_map(|p| crate::vocab::at_rule_rank(p).map(|rank| (rank, *p)))
5706− at.sort_unstable();
5708− let mut normal: String = at.iter().map(|(_, p)| *p).collect();
5709− for prefix in prefixes
5711− .filter(|p| crate::vocab::at_rule_rank(p).is_none())
5713− normal.push_str(prefix);
5715− normal.push_str(name);
5719−/// `[$name]` where `$name` isn't an attribute bundle.
5720−fn not_a_bundle(name: &str, line: usize, column: Option<usize>, ctx: &mut ParseContext) {
5721− track_var_refs(&format!("${}", name), &mut ctx.used_variables);
5722− let is_value = interp::name_len(name) > 0 && interp::resolve(name, &ctx.env).is_some();
5723− let diagnostic = if is_value {
5725− code::ATTRIBUTE_FROM_VARIABLE,
5728− "'${}' is a value, not an attribute: attributes come from a bundle \
5729− (`@let name [padding 8]`, used as `[$name]`), and a value fills an \
5730− attribute's value (`padding ${}`)",
5735− } else if ctx.env.function(name).is_some() {
5736− ctx.used_functions.insert(name.to_string());
5738− code::UNDEFINED_VARIABLE,
5741− "'${}' is a function, not an attribute bundle: it is called as an element, \
5748− let mut bundles = ctx.env.bundle_names();
5749− bundles.sort_unstable();
5750− let suggestion = suggest_closest(name, &bundles);
5751− let message = match suggestion {
5752− Some(closest) => format!(
5753− "undefined attribute bundle '${}', did you mean '${}'?",
5756− None => format!("undefined attribute bundle '${}'", name),
5758− Diagnostic::error(code::UNDEFINED_VARIABLE, line, message)
5760− .suggest(suggestion)
5762− let diagnostic = match (&ctx.current_source, column) {
5763− ((current, Some(text)), Some(column)) if *current == line => {
5764− diagnostic.column(column).source(text.clone())
5768− ctx.diagnostics.push(diagnostic);
5771−// ---------------------------------------------------------------------------
5772−// Text segment parsing (inline {...} elements)
5773−// ---------------------------------------------------------------------------
5775−/// While a slot is filled in, each escape (see [`syntax::ESCAPES`]) is a
5776−/// private-use placeholder, U+E000 plus its place in the table, so it
5777−/// can't start a variable, a quote or an inline element. Afterwards it
5778−/// becomes what it stands for.
5779−fn protect_escapes(text: &str) -> String {
5780− if !text.contains('\\') {
5781− return text.to_string();
5783− let mut out = String::with_capacity(text.len());
5785− while let Some(c) = text[i..].chars().next() {
5786− let len = syntax::escape_len(&text[i..]);
5792− let escape = &text[i..i + len];
5793− let index = syntax::ESCAPES.iter().position(|e| *e == escape);
5794− out.extend(index.and_then(|n| char::from_u32(0xE000 + n as u32)));
5800−/// The escape a placeholder stands for, as written (`\,`).
5801−fn escape_of(c: char) -> Option<&'static str> {
5802− let index = (c as u32).checked_sub(0xE000)?;
5803− syntax::ESCAPES.get(index as usize).copied()
5806−fn restore_escapes(text: &str) -> String {
5808− .fold(String::with_capacity(text.len()), |mut out, c| {
5809− match escape_of(c) {
5810− // What the escape stands for: what follows the backslash
5811− Some(escape) => out.push_str(&escape[1..]),
5812− None => out.push(c),
5818−/// Inside the quoted strings of a CSS value, `\"` and `\\` mean in CSS what
5819−/// they mean in htmlang, so they stay as written there.
5820−fn keep_css_string_escapes(protected: &str) -> String {
5821− let mut out = String::with_capacity(protected.len());
5822− let mut inside = false;
5823− for c in protected.chars() {
5824− match escape_of(c) {
5825− Some(escape @ ("\\\"" | "\\\\")) if inside => out.push_str(escape),
5837−/// Evaluate text: fill in the variables of its plain runs and build its
5838−/// inline elements. Each run is one slot, so a value can't make markup.
5839−fn text_segments(text: &syntax::Text, ctx: &mut ParseContext) -> Vec<TextSegment> {
5840− let mut segments = Vec::new();
5841− // The plain text so far, and where it starts
5842− let mut plain = String::new();
5843− let mut start: Option<syntax::Span> = None;
5844− let flush = |plain: &mut String,
5845− start: &mut Option<syntax::Span>,
5846− segments: &mut Vec<TextSegment>,
5847− ctx: &mut ParseContext| {
5848− if !plain.is_empty() {
5849− let at = start.unwrap_or(text.span);
5850− let filled = ctx.interpolate_text(plain, at.line, Some(at.column));
5851− segments.push(TextSegment::Plain(filled));
5856− for segment in &text.segments {
5858− Segment::Plain { raw, span } => {
5859− start.get_or_insert(*span);
5860− plain.push_str(raw);
5862− Segment::Inline(inline) => {
5863− let line = ctx.current_line;
5864− match resolve(&inline.head, inline.text.as_ref(), line, &text.raw, ctx) {
5866− if !inline.closed {
5867− let d = Diagnostic::warning(
5868− code::UNCLOSED_BRACKET,
5871− "unclosed `{{`: the inline @{} runs to the end of the line. \
5872− An inline element ends with `}}` (a brace that is text is \
5877− let d = at_attribute(d, Some(inline.span.column), ctx);
5880− flush(&mut plain, &mut start, &mut segments, ctx);
5881− // A function called inline gets no children: its
5882− // content is the text after its attributes
5883− match Evaluator.complete(resolved, Vec::new(), ctx) {
5884− Ok(nodes) => segments.extend(inline_segments(nodes, line)),
5887− .get_or_insert_with(|| text.raw.as_str().into());
5888− ctx.diagnostics.push(e);
5893− // A misspelled element is an error inline too (a
5894− // brace that is text is written `\{`); the braces
5896− e.source_line = Some(text.raw.as_str().into());
5897− ctx.diagnostics.push(e);
5898− start.get_or_insert(inline.span);
5900− plain.push_str(&inline.raw);
5909− flush(&mut plain, &mut start, &mut segments, ctx);
5913−/// The variable `raw` is, when it is exactly one `$name` or `${name}`.
5914−fn whole_reference(raw: &str, env: &Env) -> Option<String> {
5915− let after = raw.trim().strip_prefix('$')?;
5916− match interp::reference(after, env)? {
5917− (interp::Reference::Var(path), len) if len == after.len() => Some(path),
5922−/// The attributes of `tokens` after each whole-attribute `if()` has
5923−/// chosen (see [`syntax::Choice`]), in order, into `out`. The branch not
5924−/// taken isn't evaluated; with `validate`, its attribute names are checked
5925−/// like code that doesn't run, under the prefixes `prefix` the `if()` is
5926−/// under (`hover:if(...)`).
5928− tokens: &[syntax::Attr],
5931− ctx: &mut ParseContext,
5933− text_keys: &[String],
5934− out: &mut Vec<syntax::Attr>,
5936− for token in tokens {
5937− let Some(choice) = &token.choice else {
5938− out.push(token.clone());
5941− let Some(condition) = choice_shape(token, choice, line_num, ctx) else {
5944− let taken = match condition.span.line {
5945− 0 => ctx.condition(&condition.raw, line_num, None),
5946− line => ctx.condition(&condition.raw, line, Some(condition.span.column)),
5948− let (chosen, other) = match taken {
5949− true => (choice.branches.first(), choice.branches.get(1)),
5950− false => (choice.branches.get(1), choice.branches.first()),
5952− if let Some(other) = other {
5953− track_var_refs(&branch_text(other), &mut ctx.used_variables);
5955− check_branch(token, other, prefix, line_num, ctx, text_keys);
5958− if let Some(branch) = chosen {
5972−/// Report what is wrong with the shape of `if()`: an empty condition, a
5973−/// number of branches other than one or two, text after a group's `]`.
5974−/// Returns the condition when the `if()` can be evaluated.
5975−fn choice_shape<'a>(
5976− token: &syntax::Attr,
5977− choice: &'a syntax::Choice,
5979− ctx: &mut ParseContext,
5980−) -> Option<&'a syntax::Arg> {
5981− let line = if token.span.line == 0 {
5986− // The line the column points into, when it is the one being evaluated
5987− let source = |ctx: &ParseContext, diagnostic: Diagnostic, at: usize| match &ctx.current_source {
5988− (current, Some(text)) if *current == at => diagnostic.source(text.clone()),
5991− for branch in &choice.branches {
5992− if let syntax::Branch::Group {
5993− trailing: Some(trailing),
5997− let diagnostic = source(
6000− code::UNEXPECTED_ARGUMENT,
6001− trailing.span.line,
6003− "'{}' after the `]` of a group in if(): a branch is one attribute, \
6004− one `[group]` of attributes or one `$bundle`",
6008− .column(trailing.span.column)
6009− .subject(trailing.raw.as_str()),
6010− trailing.span.line,
6012− ctx.push_once(diagnostic);
6015− match &choice.condition {
6016− Some(condition) if (1..=2).contains(&choice.branches.len()) => Some(condition),
6018− let diagnostic = source(
6021− code::INVALID_EXPRESSION,
6024− "`{}`: if() takes a condition and one or two branches, \
6025− `if(CONDITION, A, B)`",
6029− .column(token.span.column),
6032− ctx.push_once(diagnostic);
6038−/// A branch's text, for the names it uses.
6039−fn branch_text(branch: &syntax::Branch) -> String {
6040− let raws: Vec<&str> = branch.attrs().iter().map(|a| a.raw.as_str()).collect();
6044−/// Check attributes that are never evaluated (in code that doesn't run,
6045−/// or the branch an `if()` didn't take), as far as they can be checked:
6046−/// names are, and literal values; a value with a variable depends on what
6047−/// the variable holds. Each branch of an `if()` is checked on its own.
6048−fn check_attrs(tokens: &[syntax::Attr], line: usize, ctx: &mut ParseContext, text_keys: &[String]) {
6049− parse_attr_list(&literal_attrs(tokens), line, ctx, true, text_keys);
6050− check_choices(tokens, "", line, ctx, text_keys);
6053−/// [`check_attrs`] for a branch of the `if()` `token`, under the prefixes
6054−/// `prefix` it is under: `hover:if($on, color red, [id=x])` checks
6055−/// `hover:[id=x]`, an error whichever branch is taken.
6057− token: &syntax::Attr,
6058− branch: &syntax::Branch,
6061− ctx: &mut ParseContext,
6062− text_keys: &[String],
6064− if prefix.is_empty() {
6065− check_attrs(branch.attrs(), line, ctx, text_keys);
6068− let list = syntax::AttrList {
6069− attrs: branch.attrs().to_vec(),
6072− quoted_close: None,
6074− let grouped = syntax::Attr {
6075− key: prefix.to_string(),
6078− raw: token.raw.clone(),
6081− prefixed: Some(Box::new(syntax::Prefixed {
6082− prefix: prefix.to_string(),
6083− prefix_span: token.span,
6084− target: syntax::Branch::Group {
6090− check_attrs(std::slice::from_ref(&grouped), line, ctx, text_keys);
6093−/// [`check_attrs`] for the branches of each `if()` of `tokens`, which are
6094−/// under the prefixes `prefix`, also inside a prefixed group or as a
6095−/// prefixed `if()`.
6097− tokens: &[syntax::Attr],
6100− ctx: &mut ParseContext,
6101− text_keys: &[String],
6103− for token in tokens {
6104− if let Some(choice) = &token.choice
6105− && choice_shape(token, choice, line, ctx).is_some()
6107− for branch in &choice.branches {
6108− check_branch(token, branch, prefix, line, ctx, text_keys);
6111− if let Some(prefixed) = &token.prefixed {
6112− let inner = format!("{}{}", prefix, prefixed.prefix);
6113− check_choices(prefixed.target.attrs(), &inner, line, ctx, text_keys);
6118−// ---------------------------------------------------------------------------
6119−// Post-parse validation (context-dependent warnings)
6120−// ---------------------------------------------------------------------------
6122−fn element_kind_name(kind: &ElementKind) -> String {
6123− format!("@{}", kind.name())
6126−/// HTML elements whose start tag ends an open `<p>`: written inside a
6127−/// `@paragraph`, the browser moves them out of it. (`div` isn't here:
6128−/// inside text, htmlang writes its `<div>`s as `<span>`s.)
6130−const ENDS_A_PARAGRAPH: &[&str] = &[
6131− "address", "article", "aside", "blockquote", "dd", "details", "dialog", "dl", "dt",
6132− "fieldset", "figcaption", "figure", "footer", "form", "h1", "h2", "h3", "h4", "h5", "h6",
6133− "header", "hgroup", "hr", "li", "main", "menu", "nav", "ol", "p", "pre", "search",
6134− "section", "summary", "table", "ul",
6137−/// The HTML element `kind` is written as, if the browser would take it out
6139−fn ends_a_paragraph(kind: &ElementKind) -> Option<&'static str> {
6140− let html = match kind {
6141− ElementKind::Paragraph => "p",
6142− ElementKind::Tag(spec) => spec.html,
6145− ENDS_A_PARAGRAPH.contains(&html).then_some(html)
6148−/// Stricter checks for `htmlang lint`, on top of the diagnostics every
6149−/// compile reports: deep nesting, empty layout containers, and buttons
6150−/// without an explicit `type`.
6151−pub fn lint(nodes: &[Node]) -> Vec<Diagnostic> {
6152− fn walk(nodes: &[Node], depth: usize, out: &mut Vec<Diagnostic>) {
6153− for node in nodes {
6154− let Node::Element(elem) = node else { continue };
6155− let start = out.len();
6156− let mut warn = |code: &'static str, message: String| {
6157− out.push(Diagnostic::warning(code, elem.line_num, message))
6161− code::DEEP_NESTING,
6163− "deeply nested element ({} levels): consider simplifying",
6168− // A function's body may draw with an empty element (a spacer,
6169− // a dot): only one written in the page is flagged
6170− if elem.kind.layout().is_container()
6171− && elem.children.is_empty()
6172− && elem.function.is_none()
6175− code::EMPTY_CONTAINER,
6176− format!("empty container (@{}) has no children", elem.kind.name()),
6179− if elem.kind.is_tag("button") && !elem.attrs.iter().any(|a| a.key == "type") {
6181− code::MISSING_BUTTON_TYPE,
6182− "@button missing 'type' attribute (defaults to submit)".to_string(),
6185− in_function_body(elem, &mut out[start..]);
6186− walk(&elem.children, depth + 1, out);
6189− let mut out = Vec::new();
6190− walk(nodes, 0, &mut out);
6195−/// `in_paragraph`: the nodes are inside a `@paragraph` (and not inside a
6196−/// `@button` in it, which the browser keeps whole).
6199− parent_kind: Option<&ElementKind>,
6200− in_paragraph: bool,
6201− diagnostics: &mut Vec<Diagnostic>,
6203− for node in nodes {
6204− // An element inside a line of text (`{@kbd ...}`, an inline call)
6205− // is checked like one on a line of its own
6206− if let Node::Text(segments) = node {
6207− let inline: Vec<Node> = segments
6209− .filter_map(|segment| match segment {
6210− TextSegment::Inline(elem) => Some(Node::Element(elem.clone())),
6214− validate_tree(&inline, parent_kind, in_paragraph, diagnostics);
6216− if let Node::Element(elem) = node {
6217− let start = diagnostics.len();
6218− dropped_by_the_element(elem, diagnostics);
6219− if in_paragraph && let Some(html) = ends_a_paragraph(&elem.kind) {
6221− Diagnostic::warning(
6222− code::BLOCK_IN_PARAGRAPH,
6225− "{0} inside @paragraph: HTML ends a <p> before a <{1}>, so the \
6226− browser moves the <{1}> out of the paragraph. Put {0} after the \
6227− paragraph, or use @el, @row or @grid, which are laid out inline \
6229− element_kind_name(&elem.kind),
6233− .subject(elem.kind.name()),
6236− for attr in &elem.attrs {
6237− let base = crate::vocab::base_attribute(&attr.key);
6239− // htmlang's words for laying out children, on an element
6240− // that doesn't lay out its children: left out (codegen)
6242− && crate::vocab::CONTAINER_ATTRIBUTES.contains(&base)
6243− && !elem.kind.layout().is_container()
6244− && !has_no_element(&elem.kind)
6245− && !crate::vocab::split_prefixes(&attr.key)
6247− .contains(&"children:")
6249− diagnostics.push(not_a_container(&elem.kind, elem.line_num, base));
6252− // Form-specific: placeholder only on @input/@textarea
6253− if base == "placeholder"
6254− && !(elem.kind.is_tag("input") || elem.kind.is_tag("textarea"))
6256− diagnostics.push(Diagnostic::new(
6261− "'placeholder' has no effect on {} (only works on @input, @textarea)",
6262− element_kind_name(&elem.kind)
6267− // 'for' only on @label and @output
6268− if base == "for" && !(elem.kind.is_tag("label") || elem.kind.is_tag("output")) {
6269− diagnostics.push(Diagnostic::new(
6274− "'for' has no effect on {} (only works on @label and @output)",
6275− element_kind_name(&elem.kind)
6280− // `width=` and `height=` are HTML attributes of media and
6281− // embedded content only; elsewhere they are styles
6283− && (base == "width" || base == "height")
6284− && !matches!(elem.kind, ElementKind::Image)
6286− "video", "canvas", "iframe", "embed", "object", "input", "source",
6289− .any(|tag| elem.kind.is_tag(tag))
6291− let value = attr.value.as_deref().unwrap_or("");
6293− Diagnostic::warning(
6294− code::HTML_ATTRIBUTE_FORM,
6297− "'{0}={1}' has no effect on {2}, which has no {0} attribute: \
6298− the style is written `{0} {1}`",
6301− element_kind_name(&elem.kind)
6304− .subject(format!("{}={}", base, value)),
6308− // 'rows'/'cols' only on @textarea
6309− if (base == "rows" || base == "cols") && !elem.kind.is_tag("textarea") {
6310− diagnostics.push(Diagnostic::new(
6315− "'{}' has no effect on {} (only works on @textarea)",
6317− element_kind_name(&elem.kind)
6322− // Media-specific attributes only on @video/@audio
6332− ) && !matches!(elem.kind.name(), "video" | "audio")
6334− diagnostics.push(Diagnostic::new(
6339− "'{}' has no effect on {} (only works on @video, @audio)",
6341− element_kind_name(&elem.kind)
6346− // Missing alt text on @image
6347− if matches!(elem.kind, ElementKind::Image) && !elem.attrs.iter().any(|a| a.key == "alt")
6349− diagnostics.push(Diagnostic::new(
6353− "@image missing 'alt' attribute (accessibility)".to_string(),
6356− if elem.kind.is_tag("input") && !elem.attrs.iter().any(|a| a.key == "type") {
6357− diagnostics.push(Diagnostic::new(
6358− code::MISSING_INPUT_TYPE,
6361− "@input missing 'type' attribute (defaults to 'text')".to_string(),
6364− if matches!(elem.kind, ElementKind::Link) {
6365− // For @link, argument is the URL, not text content
6366− let has_text = !elem.children.is_empty();
6371− .any(|a| a.key == "aria-label" || a.key == "title")
6373− diagnostics.push(Diagnostic::new(
6374− code::MISSING_LINK_TEXT,
6377− "@link has no visible text or aria-label (accessibility)".to_string(),
6382− // Contrast ratio check for hex color pairs, each pair on the
6383− // same elements: the element's own, or those an element prefix
6384− // (`@td:`) picks out inside it
6385− let inside = |key: &str| {
6386− crate::vocab::split_prefixes(key)
6389− .find_map(crate::vocab::element_prefix)
6390− .map(str::to_string)
6392− let mut targets: Vec<Option<String>> = Vec::new();
6393− for attr in elem.attrs.iter().filter(|a| !a.html) {
6394− let target = inside(&attr.key);
6395− if !targets.contains(&target) {
6396− targets.push(target);
6399− for target in targets {
6400− let color = |property: &str| {
6403− .filter(|a| !a.html && inside(&a.key) == target)
6404− .find(|a| crate::vocab::base_attribute(&a.key) == property)
6405− .and_then(|a| a.value.as_deref())
6407− let (bg_color, fg_color) = (color("background"), color("color"));
6408− if let (Some(bg), Some(fg)) = (bg_color, fg_color)
6409− && let (Some(bg_rgb), Some(fg_rgb)) = (parse_hex_rgb(bg), parse_hex_rgb(fg))
6411− let ratio = contrast_ratio(bg_rgb, fg_rgb);
6413− diagnostics.push(Diagnostic::new(code::LOW_CONTRAST, Severity::Warning, elem.line_num, format!(
6414− "low contrast ratio {:.1}:1 between '{}' and '{}' (WCAG AA requires 4.5:1)",
6421− // @form inputs should have associated @label
6422− if matches!(elem.kind.name(), "input" | "select" | "textarea") {
6423− let has_id = elem.attrs.iter().any(|a| a.key == "id");
6424− let has_aria_label = elem
6427− .any(|a| a.key == "aria-label" || a.key == "aria-labelledby");
6428− let has_title = elem.attrs.iter().any(|a| a.key == "title");
6429− let in_label = parent_kind.is_some_and(|k| k.is_tag("label"));
6430− if !has_id && !has_aria_label && !has_title && !in_label {
6431− diagnostics.push(Diagnostic::new(code::MISSING_LABEL, Severity::Warning, elem.line_num, format!(
6432− "{} should have an 'id' (with matching @label[for]), 'aria-label', or be wrapped in @label (accessibility)",
6433− element_kind_name(&elem.kind)
6438− // @iframe should have title attribute
6439− if elem.kind.is_tag("iframe") && !elem.attrs.iter().any(|a| a.key == "title") {
6440− diagnostics.push(Diagnostic::new(
6441− code::MISSING_TITLE,
6444− "@iframe missing 'title' attribute (accessibility)".to_string(),
6448− // @button should have accessible text
6449− if elem.kind.is_tag("button") {
6450− let has_text = !elem.children.is_empty();
6451− let has_aria = elem.attrs.iter().any(|a| a.key == "aria-label");
6452− if !has_text && !has_aria {
6453− diagnostics.push(Diagnostic::new(
6454− code::MISSING_BUTTON_TEXT,
6457− "@button has no text content or aria-label (accessibility)".to_string(),
6462− // @video should have captions or aria-label
6463− if elem.kind.is_tag("video") {
6464− let has_aria = elem
6467− .any(|a| a.key == "aria-label" || a.key == "aria-describedby");
6468− let has_track = elem
6471− .any(|c| matches!(c, Node::Element(e) if e.kind.is_tag("track")));
6472− if !has_aria && !has_track {
6473− diagnostics.push(Diagnostic::new(
6474− code::MISSING_CAPTIONS,
6477− "@video should have aria-label or a captions @track for accessibility"
6483− // Tabindex > 0 is an anti-pattern
6484− if let Some(tabindex_attr) = elem.attrs.iter().find(|a| a.key == "tabindex")
6485− && let Some(ref val) = tabindex_attr.value
6486− && let Ok(n) = val.parse::<i32>()
6489− 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)));
6491− in_function_body(elem, &mut diagnostics[start..]);
6493− // An element that ends the <p> takes what is inside it out of
6494− // the paragraph too, so only it is reported
6495− let in_paragraph = elem.kind == ElementKind::Paragraph
6497− && ends_a_paragraph(&elem.kind).is_none()
6498− && !elem.kind.is_tag("button"));
6499− validate_tree(&elem.children, Some(&elem.kind), in_paragraph, diagnostics);
6504−/// What an element has no place for in HTML, which would otherwise be
6505−/// left out of the page: attributes on `@fragment` (which has no element
6506−/// of its own), styles on `@script` (which isn't shown), a body under a
6507−/// `@script` that has a src (which the browser doesn't run), an element
6508−/// under a `@script` (whose body is code), and content in a void element
6509−/// such as `@input`.
6510−fn dropped_by_the_element(elem: &Element, diagnostics: &mut Vec<Diagnostic>) {
6511− let name = elem.kind.name();
6512− let keys = |attrs: Vec<&Attribute>| {
6515− .map(|a| format!("'{}'", a.key))
6516− .collect::<Vec<_>>()
6519− let mut error = |code: &'static str, message: String| {
6520− diagnostics.push(Diagnostic::error(code, elem.line_num, message).subject(name))
6522− if elem.kind == ElementKind::Fragment && !elem.attrs.is_empty() {
6524− code::UNEXPECTED_ARGUMENT,
6526− "@fragment has no element of its own to put attributes on, so {} would go \
6527− nowhere: put them on its children, or use @el",
6528− keys(elem.attrs.iter().collect())
6532− // The leading argument given twice: an attribute passed to the root
6533− // of a function whose body gives the argument (written on one line,
6534− // it is reported where it is read, and the attribute wins there)
6535− if let Some(argument) = &elem.argument
6536− && let Some(attr) = elem
6539− .find(|a| a.html && elem.kind.arg().attributes().contains(&a.key.as_str()))
6542− code::DUPLICATE_ATTRIBUTE,
6544− "@{} takes '{}' as its {}, and it also has {}={}: give it once",
6547− leading_name(&elem.kind),
6549− attr.value.as_deref().unwrap_or("")
6553− if elem.kind.is_verbatim() {
6554− let styles: Vec<&Attribute> = elem
6557− .filter(|a| !a.html && !crate::vocab::is_html_flag(&a.key))
6559− if !styles.is_empty() {
6561− code::UNEXPECTED_ARGUMENT,
6563− "@{} isn't shown on the page, so its styles {} would go nowhere",
6569− let src = elem.argument.clone().or_else(|| {
6572− .find(|a| a.html && a.key == "src")
6573− .map(|a| a.value.clone().unwrap_or_default())
6575− if let Some(src) = src
6576− && !elem.children.is_empty()
6579− code::UNEXPECTED_CONTENT,
6581− "@{0} has both a src ('{1}') and a body: the browser runs only the file, \
6582− so the body would go nowhere. Put the code in {1}, or leave out the src",
6586− } else if let Some(Node::Element(child)) = elem
6589− .find(|child| matches!(child, Node::Element(_)))
6591− // `@script > @b x`: its body is code, not elements
6593− code::UNEXPECTED_CONTENT,
6595− "@{} holds its code as the lines under it, kept as written, so @{} would \
6603− if elem.kind != ElementKind::Image && elem.attrs.iter().any(|a| !a.html && a.key == "inline") {
6605− code::UNEXPECTED_ARGUMENT,
6607− "`inline` puts an image's file into the page, and @{} has none: it only \
6613− if elem.kind.layout() == Layout::Void && !elem.children.is_empty() {
6615− code::UNEXPECTED_CONTENT,
6617− "@{} takes no content: it is an element without a closing tag, so its text \
6618− and indented lines would go nowhere",
6625−/// `@fragment`, `@script`, `@children` and `@slot`, whose attributes are
6626−/// reported on their own (see `dropped_by_the_element`).
6627−fn has_no_element(kind: &ElementKind) -> bool {
6630− ElementKind::Fragment | ElementKind::Children | ElementKind::Slot(_)
6631− ) || kind.is_verbatim()
6634−/// htmlang's word `word` for laying out children (`spacing`, `wrap`,
6635−/// `grid-cols`, `grid-rows`) on an element that doesn't lay out its
6636−/// children: an error, and the word is left out.
6637−fn not_a_container(kind: &ElementKind, line: usize, word: &str) -> Diagnostic {
6638− let name = element_kind_name(kind);
6639− let (what, instead) = match kind.layout() {
6641− "is text, whose lines and children flow together with no gap between them",
6642− "; to space the children out, put them in an @el or @row",
6644− Layout::Void => ("has no content to lay out", ""),
6646− "keeps HTML's own layout",
6647− "; for a flex layout of your own, write CSS, such as `display flex, gap 8`",
6654− "'{0}' can't go on {1}: {1} {2}. `{0}` works on a row, column or grid \
6655− (@el, @row, @grid, @section, ...){3}",
6656− word, name, what, instead
6662−/// Diagnostics about an element a function's body wrote are reported at
6663−/// the call (see `belongs_to_call`); say which body the element is in.
6664−fn in_function_body(elem: &Element, diagnostics: &mut [Diagnostic]) {
6665− if let Some(function) = &elem.function {
6666− for d in diagnostics {
6667− d.message = format!("{}\n in the body of @{}", d.message, function);
6672−/// Report each diagnostic once: a line that runs many times (in a loop, in
6673−/// a function called from one place many times) reports its problems once.
6674−fn dedupe(diagnostics: &mut Vec<Diagnostic>) {
6675− let mut seen = HashSet::new();
6676− diagnostics.retain(|d| {
6687−fn relative_luminance(r: u8, g: u8, b: u8) -> f64 {
6688− fn linearize(c: u8) -> f64 {
6689− let s = c as f64 / 255.0;
6693− ((s + 0.055) / 1.055).powf(2.4)
6696− 0.2126 * linearize(r) + 0.7152 * linearize(g) + 0.0722 * linearize(b)
6699−/// The red, green and blue of a `#rgb` or `#rrggbb` colour.
6700−fn parse_hex_rgb(s: &str) -> Option<(u8, u8, u8)> {
6701− let s = s.strip_prefix('#')?;
6702− if !s.bytes().all(|b| b.is_ascii_hexdigit()) {
6705− let channel = |i: usize, len: usize| u8::from_str_radix(&s[i..i + len], 16).ok();
6708− channel(0, 1)? * 17,
6709− channel(1, 1)? * 17,
6710− channel(2, 1)? * 17,
6712− 6 => Some((channel(0, 2)?, channel(2, 2)?, channel(4, 2)?)),
6717−fn contrast_ratio(c1: (u8, u8, u8), c2: (u8, u8, u8)) -> f64 {
6718− let l1 = relative_luminance(c1.0, c1.1, c1.2);
6719− let l2 = relative_luminance(c2.0, c2.1, c2.2);
6720− let (lighter, darker) = if l1 > l2 { (l1, l2) } else { (l2, l1) };
6721− (lighter + 0.05) / (darker + 0.05)
6724−/// `@image [inline] icon.svg` becomes the SVG's markup, with `width`,
6725−/// `height`, `color` / `fill` and the HTML attributes (`class=`, `id=`,
6726−/// `aria-label=`, ...) applied to the `<svg>` tag; any other attribute is
6727−/// an error. Other nodes are returned unchanged.
6728−fn inline_svg(node: Node, line_num: usize, ctx: &mut ParseContext) -> Node {
6729− let Node::Element(elem) = &node else {
6732− let inline = elem.kind == ElementKind::Image
6733− && elem.attrs.iter().any(|a| a.key == "inline" && !a.html)
6734− && elem.argument.as_deref().is_some_and(|src| !src.is_empty());
6738− // A raster image: its file, read relative to this one, as a `data:` URI
6742− .is_some_and(|src| src.ends_with(".svg"))
6744− let Node::Element(mut elem) = node else {
6747− let filename = elem.argument.clone().unwrap_or_default();
6748− let resolved = ctx.resolve(&filename);
6749− match std::fs::read(&resolved) {
6751− elem.argument = Some(crate::codegen::data_uri(&filename, &data));
6752− ctx.included_files.push(resolved);
6754− Err(e) => ctx.diagnostics.push(Diagnostic::new(
6755− code::UNREADABLE_FILE,
6759− "cannot load image '{}' to put it into the page: {}",
6764− return Node::Element(elem);
6766− let filename = elem.argument.clone().unwrap_or_default();
6767− let resolved = match &ctx.base_path {
6768− Some(base) => base.join(&filename),
6769− None => PathBuf::from(&filename),
6771− let mut svg = match std::fs::read_to_string(&resolved) {
6772− Ok(text) => text.trim().to_string(),
6774− ctx.diagnostics.push(Diagnostic::new(
6775− code::UNREADABLE_FILE,
6778− format!("cannot load SVG '{}': {}", filename, e),
6783− ctx.included_files.push(resolved);
6784− // The file's markup has no class of its own, so a style reaches it only
6785− // as one of the root's attributes: anything else is reported, never
6786− // left out silently
6787− let mut left_out: Vec<String> = Vec::new();
6788− // The styles go in the root's `style=`, where a length takes its unit
6789− // and `var(--name)` works, as in any CSS
6790− let mut style: Vec<String> = Vec::new();
6791− for attr in &elem.attrs {
6792− let target = match (attr.key.as_str(), attr.html, &attr.value) {
6793− ("inline", false, None) | ("src", true, _) => continue,
6794− // `fill` and `shrink` are layout words, which need a class
6795− ("width" | "height", false, Some(value))
6796− if matches!(value.as_str(), "fill" | "shrink") =>
6798− left_out.push(format!("{} {}", attr.key, value));
6801− ("width" | "height", false, Some(value)) => {
6802− let value = crate::vocab::with_px(&attr.key, value);
6803− style.push(format!("{}:{}", attr.key, value));
6806− ("color" | "fill", false, Some(value)) => {
6807− style.push(format!("fill:{}", value));
6810− ("style", true, Some(value)) => {
6811− style.insert(0, value.trim().trim_end_matches(';').to_string());
6814− ("alt", true, _) => {
6815− left_out.push("alt".to_string());
6818− (key, true, Some(_)) => key,
6819− (key, false, None) if crate::vocab::is_html_flag(key) => key,
6821− left_out.push(attr.key.clone());
6825− let value = attr.value.as_deref().unwrap_or("");
6826− svg = set_svg_attr(&svg, target, &html_escape_md(value));
6828− if !style.is_empty() {
6829− // After the file's own `style=`, which stays: these come later, so
6830− // they win where both set a property
6831− let mut value = html_escape_md(&style.join(";"));
6832− if let Some(own) = svg_attr_value(&svg, "style")
6833− .map(|range| svg[range].trim().trim_end_matches(';').to_string())
6834− .filter(|own| !own.is_empty())
6836− value = format!("{};{}", own, value);
6838− svg = set_svg_attr(&svg, "style", &value);
6840− if !left_out.is_empty() {
6841− let alt = left_out.iter().any(|name| name == "alt");
6842− let names = left_out
6844− .map(|name| format!("'{}'", name))
6845− .collect::<Vec<_>>()
6847− let mut message = format!(
6848− "{} 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=`, ...)",
6852− message.push_str("; an SVG has no alt text: name it with `aria-label=` and `role=img`");
6854− ctx.diagnostics.push(Diagnostic::new(
6855− code::UNEXPECTED_ARGUMENT,
6864−// ---------------------------------------------------------------------------
6865−// Variable usage tracking
6866−// ---------------------------------------------------------------------------
6868−/// Record the names a string refers to (by syntax) as used.
6869−fn track_var_refs(input: &str, used: &mut HashSet<String>) {
6870− if input.contains('$') {
6871− used.extend(interp::names(input).into_iter().map(String::from));
6875−// ---------------------------------------------------------------------------
6876−// Unused definition warnings
6877−// ---------------------------------------------------------------------------
6879−/// Warn about definitions nothing uses, except `exported` ones (the
6880−/// definitions of a library, for the files that include it).
6881−fn check_unused(ctx: &mut ParseContext, exported: &HashSet<String>) {
6882− // Check unused @let variables
6883− for (name, &line) in &ctx.let_lines {
6884− if exported.contains(name) {
6885− // A library's names are for other files (a custom property
6886− // isn't a variable, so it is never listed here)
6889− if !ctx.used_variables.contains(name) {
6890− ctx.diagnostics.push(
6892− code::UNUSED_VARIABLE,
6895− format!("unused variable '${}' (defined but never referenced)", name),
6897− .subject(name.as_str()),
6902− // Check unused attribute bundles (@let name [...]). A `$name` in code
6903− // that doesn't run (an `if()` branch or `@if` not taken) counts too.
6904− for (name, &line) in &ctx.define_lines {
6905− if !ctx.used_defines.contains(name)
6906− && !ctx.used_variables.contains(name)
6907− && !exported.contains(name)
6909− ctx.diagnostics.push(
6911− code::UNUSED_BUNDLE,
6915− "unused attribute bundle '${}' (defined but never referenced)",
6919− .subject(name.as_str()),
6924− // Check unused functions (@let name ... with body)
6925− for (name, &line) in &ctx.fn_lines {
6926− if !ctx.used_functions.contains(name) && !exported.contains(name) {
6927− ctx.diagnostics.push(
6929− code::UNUSED_FUNCTION,
6932− format!("unused function '@{}' (defined but never called)", name),
6934− .subject(name.as_str()),
6940−// ---------------------------------------------------------------------------
6941−// Minimal JSON parser for @data directive
6942−// ---------------------------------------------------------------------------
6944−#[derive(Debug, Clone)]
6950− Array(Vec<JsonValue>),
6951− Object(Vec<(String, JsonValue)>),
6954−/// Parse JSON with an error message indicating where parsing failed.
6955−fn parse_json_with_error(input: &str) -> Result<JsonValue, String> {
6956− let trimmed = input.trim();
6957− if trimmed.is_empty() {
6958− return Err("empty input".to_string());
6960− let chars: Vec<char> = trimmed.chars().collect();
6961− match parse_json_value(&chars, 0) {
6962− Some((val, _)) => Ok(val),
6964− // Find approximate error position by parsing as far as possible
6965− let mut deepest = 0usize;
6966− fn probe(chars: &[char], pos: usize, deepest: &mut usize) {
6968− while p < chars.len() {
6975− probe(chars, p, deepest);
6980− while p < chars.len() && chars[p] != '"' {
6981− if chars[p] == '\\' {
6986− if p < chars.len() {
7000− probe(&chars, 0, &mut deepest);
7001− // Convert char position to line:col
7002− let prefix: String = chars[..deepest.min(chars.len())].iter().collect();
7003− let line = prefix.chars().filter(|&c| c == '\n').count() + 1;
7006− .map_or(prefix.len(), |p| prefix.len() - p - 1)
7008− let context: String = chars[deepest.saturating_sub(20)..deepest.min(chars.len())]
7012− "at line {}:{} near \"{}\"",
7021−fn parse_json_value(chars: &[char], mut pos: usize) -> Option<(JsonValue, usize)> {
7022− pos = skip_ws(chars, pos);
7023− if pos >= chars.len() {
7028− let (s, p) = parse_json_string(chars, pos)?;
7029− Some((JsonValue::Str(s), p))
7031− '{' => parse_json_object(chars, pos),
7032− '[' => parse_json_array(chars, pos),
7034− if chars.get(pos..pos + 4)?.iter().collect::<String>() == "true" {
7035− Some((JsonValue::Bool(true), pos + 4))
7041− if chars.get(pos..pos + 5)?.iter().collect::<String>() == "false" {
7042− Some((JsonValue::Bool(false), pos + 5))
7048− if chars.get(pos..pos + 4)?.iter().collect::<String>() == "null" {
7049− Some((JsonValue::Null, pos + 4))
7054− c if c == '-' || c.is_ascii_digit() => {
7056− if chars[pos] == '-' {
7059− while pos < chars.len()
7060− && (chars[pos].is_ascii_digit()
7061− || chars[pos] == '.'
7062− || chars[pos] == 'e'
7063− || chars[pos] == 'E'
7064− || chars[pos] == '+'
7065− || chars[pos] == '-')
7067− if (chars[pos] == '+' || chars[pos] == '-')
7069− && chars[pos - 1] != 'e'
7070− && chars[pos - 1] != 'E'
7076− let num: String = chars[start..pos].iter().collect();
7077− Some((JsonValue::Number(num), pos))
7083−fn parse_json_string(chars: &[char], mut pos: usize) -> Option<(String, usize)> {
7084− if chars.get(pos) != Some(&'"') {
7088− let mut s = String::new();
7089− while pos < chars.len() && chars[pos] != '"' {
7090− if chars[pos] == '\\' && pos + 1 < chars.len() {
7093− '"' | '\\' | '/' => s.push(chars[pos]),
7094− 'n' => s.push('\n'),
7095− 't' => s.push('\t'),
7096− 'r' => s.push('\r'),
7097− 'b' => s.push('\u{8}'),
7098− 'f' => s.push('\u{c}'),
7100− let hex4 = |at: usize| -> Option<u32> {
7101− let digits: String = chars.get(at..at + 4)?.iter().collect();
7102− u32::from_str_radix(&digits, 16).ok()
7104− let hi = hex4(pos + 1)?;
7106− let code = if (0xD800..0xDC00).contains(&hi)
7107− && chars.get(pos + 1) == Some(&'\\')
7108− && chars.get(pos + 2) == Some(&'u')
7109− && let Some(lo) = hex4(pos + 3)
7110− && (0xDC00..0xE000).contains(&lo)
7113− 0x10000 + ((hi - 0xD800) << 10) + (lo - 0xDC00)
7117− s.push(char::from_u32(code).unwrap_or('\u{FFFD}'));
7121− s.push(chars[pos]);
7125− s.push(chars[pos]);
7129− if pos < chars.len() {
7130− pos += 1; // closing quote
7135−fn parse_json_object(chars: &[char], mut pos: usize) -> Option<(JsonValue, usize)> {
7136− pos += 1; // skip '{'
7137− pos = skip_ws(chars, pos);
7138− let mut pairs = Vec::new();
7139− if pos < chars.len() && chars[pos] == '}' {
7140− return Some((JsonValue::Object(pairs), pos + 1));
7143− pos = skip_ws(chars, pos);
7144− let (key, p) = parse_json_string(chars, pos)?;
7145− pos = skip_ws(chars, p);
7146− if pos >= chars.len() || chars[pos] != ':' {
7150− let (val, p) = parse_json_value(chars, pos)?;
7152− pairs.push((key, val));
7153− pos = skip_ws(chars, pos);
7154− if pos >= chars.len() {
7157− if chars[pos] == '}' {
7161− if chars[pos] == ',' {
7165− Some((JsonValue::Object(pairs), pos))
7168−fn parse_json_array(chars: &[char], mut pos: usize) -> Option<(JsonValue, usize)> {
7169− pos += 1; // skip '['
7170− pos = skip_ws(chars, pos);
7171− let mut items = Vec::new();
7172− if pos < chars.len() && chars[pos] == ']' {
7173− return Some((JsonValue::Array(items), pos + 1));
7176− let (val, p) = parse_json_value(chars, pos)?;
7179− pos = skip_ws(chars, pos);
7180− if pos >= chars.len() {
7183− if chars[pos] == ']' {
7187− if chars[pos] == ',' {
7191− Some((JsonValue::Array(items), pos))
7194−fn skip_ws(chars: &[char], mut pos: usize) -> usize {
7195− while pos < chars.len() && chars[pos].is_ascii_whitespace() {
7201−/// A JSON value as an htmlang value: an object is a record, an array a
7202−/// list, a string text (never quoted text), `null` empty. A number keeps
7203−/// the text it is written with (`1.50`), and reads as a number.
7204−fn json_value(json: JsonValue) -> Value {
7206− JsonValue::Null => Value::empty(),
7207− JsonValue::Bool(b) => Value::Bool(b),
7208− JsonValue::Number(n) | JsonValue::Str(n) => Value::Str(n),
7209− JsonValue::Array(items) => Value::list(items.into_iter().map(json_value).collect()),
7210− JsonValue::Object(pairs) => Value::Record(Rc::new(
7213− .map(|(key, value)| (key, json_value(value)))
7219−// ---------------------------------------------------------------------------
7220−// SVG attribute injection helper
7221−// ---------------------------------------------------------------------------
7223−/// Where the root `<svg ...>` tag's `attr_name="..."` value is, as a byte
7224−/// range of `svg`. Only the opening tag is read, so a child's attribute is
7225−/// never found, and the name must follow whitespace, so `width` doesn't
7226−/// match `stroke-width`.
7227−fn svg_attr_value(svg: &str, attr_name: &str) -> Option<std::ops::Range<usize>> {
7228− let tag_start = svg.find("<svg")?;
7229− let tag_end = svg[tag_start..]
7231− .map(|p| tag_start + p)
7232− .unwrap_or(svg.len());
7233− let tag = &svg[tag_start..tag_end];
7234− let pattern = format!("{}=\"", attr_name);
7235− let (pos, _) = tag.match_indices(&pattern).find(|(pos, _)| {
7239− .is_some_and(char::is_whitespace)
7241− let value_start = tag_start + pos + pattern.len();
7242− let end = svg[value_start..tag_end].find('"')?;
7243− Some(value_start..value_start + end)
7246−fn set_svg_attr(svg: &str, attr_name: &str, value: &str) -> String {
7247− // Only the opening <svg ...> tag is touched, so child attributes such as
7248− // `stroke-width` are left alone.
7249− let Some(tag_start) = svg.find("<svg") else {
7250− return svg.to_string();
7252− let tag_end = svg[tag_start..]
7254− .map(|p| tag_start + p)
7255− .unwrap_or(svg.len());
7257− // Replace an existing attribute
7258− if let Some(existing) = svg_attr_value(svg, attr_name) {
7259− let mut result = String::with_capacity(svg.len());
7260− result.push_str(&svg[..existing.start]);
7261− result.push_str(value);
7262− result.push_str(&svg[existing.end..]);
7266− // Otherwise inject it into the opening tag (before a self-closing `/`).
7267− let insert_at = if svg[..tag_end].ends_with('/') {
7272− let mut result = String::with_capacity(svg.len() + attr_name.len() + value.len() + 4);
7273− result.push_str(svg[..insert_at].trim_end());
7275− result.push_str(attr_name);
7276− result.push_str("=\"");
7277− result.push_str(value);
7279− result.push_str(&svg[insert_at..]);
7283−// ---------------------------------------------------------------------------
7284−// Markdown → HTML conversion (minimal subset)
7285−// ---------------------------------------------------------------------------
7287−fn markdown_to_html(lines: &[String]) -> String {
7288− let mut html = String::new();
7289− // Tag of the list currently open ("ul" or "ol"), if any.
7290− let mut list: Option<&'static str> = None;
7291− let mut in_code_block = false;
7292− let mut code_lang = String::new();
7293− let mut code_buf = String::new();
7294− let mut para_buf = String::new();
7296− let flush_para = |para: &mut String, out: &mut String| {
7297− let trimmed = para.trim();
7298− if !trimmed.is_empty() {
7299− out.push_str("<p>");
7300− out.push_str(&md_inline(trimmed));
7301− out.push_str("</p>\n");
7305− let close_list = |list: &mut Option<&'static str>, out: &mut String| {
7306− if let Some(tag) = list.take() {
7307− out.push_str(&format!("</{}>\n", tag));
7310− let open_list = |list: &mut Option<&'static str>, tag: &'static str, out: &mut String| {
7311− if *list != Some(tag) {
7312− if let Some(prev) = list.take() {
7313− out.push_str(&format!("</{}>\n", prev));
7315− out.push_str(&format!("<{}>\n", tag));
7320− for line in lines {
7321− let trimmed = line.trim();
7323− // Fenced code blocks
7324− if let Some(after_fence) = trimmed.strip_prefix("```") {
7326− html.push_str("<pre><code");
7327− if !code_lang.is_empty() {
7328− html.push_str(&format!(" class=\"language-{}\"", code_lang));
7331− html.push_str(&html_escape_md(&code_buf));
7332− html.push_str("</code></pre>\n");
7335− in_code_block = false;
7337− flush_para(&mut para_buf, &mut html);
7338− close_list(&mut list, &mut html);
7339− code_lang = after_fence.trim().to_string();
7340− in_code_block = true;
7345− if !code_buf.is_empty() {
7346− code_buf.push('\n');
7348− // Keep indentation inside code blocks.
7349− code_buf.push_str(line.trim_end());
7353− // Blank line ends paragraph
7354− if trimmed.is_empty() {
7355− flush_para(&mut para_buf, &mut html);
7356− close_list(&mut list, &mut html);
7361− let heading_level = trimmed.bytes().take_while(|&b| b == b'#').count();
7362− if (1..=6).contains(&heading_level) && trimmed.as_bytes().get(heading_level) == Some(&b' ')
7364− flush_para(&mut para_buf, &mut html);
7365− close_list(&mut list, &mut html);
7366− let text = &trimmed[heading_level + 1..];
7367− html.push_str(&format!(
7376− // Horizontal rule (checked before list items so `---`/`***` aren't
7377− // mistaken for bullets)
7378− if trimmed == "---" || trimmed == "***" || trimmed == "___" {
7379− flush_para(&mut para_buf, &mut html);
7380− close_list(&mut list, &mut html);
7381− html.push_str("<hr>\n");
7385− // Unordered list items
7386− if (trimmed.starts_with("- ") || trimmed.starts_with("* ")) && trimmed.len() > 2 {
7387− flush_para(&mut para_buf, &mut html);
7388− open_list(&mut list, "ul", &mut html);
7389− html.push_str(&format!("<li>{}</li>\n", md_inline(&trimmed[2..])));
7393− // Ordered list items
7394− if let Some(dot_pos) = trimmed.find(". ")
7395− && (1..=3).contains(&dot_pos)
7396− && trimmed[..dot_pos].chars().all(|c| c.is_ascii_digit())
7398− flush_para(&mut para_buf, &mut html);
7399− open_list(&mut list, "ol", &mut html);
7400− html.push_str(&format!(
7402− md_inline(&trimmed[dot_pos + 2..])
7408− if let Some(quote_content) = trimmed.strip_prefix("> ") {
7409− flush_para(&mut para_buf, &mut html);
7410− close_list(&mut list, &mut html);
7411− html.push_str(&format!(
7412− "<blockquote><p>{}</p></blockquote>\n",
7413− md_inline(quote_content)
7418− // Otherwise, accumulate paragraph text
7419− close_list(&mut list, &mut html);
7420− if !para_buf.is_empty() {
7421− para_buf.push(' ');
7423− para_buf.push_str(trimmed);
7427− close_list(&mut list, &mut html);
7428− flush_para(&mut para_buf, &mut html);
7433−fn md_inline(text: &str) -> String {
7434− let mut result = String::new();
7435− let chars: Vec<char> = text.chars().collect();
7438− while i < chars.len() {
7439− // Bold: **text** or __text__
7440− if i + 1 < chars.len()
7441− && ((chars[i] == '*' && chars[i + 1] == '*')
7442− || (chars[i] == '_' && chars[i + 1] == '_'))
7444− let marker = chars[i];
7445− if let Some(end) = find_closing_double(&chars, i + 2, marker) {
7446− let inner: String = chars[i + 2..end].iter().collect();
7447− result.push_str("<strong>");
7448− result.push_str(&md_inline(&inner));
7449− result.push_str("</strong>");
7454− // Italic: *text* or _text_
7455− if (chars[i] == '*' || chars[i] == '_') && i + 1 < chars.len() && chars[i + 1] != chars[i] {
7456− let marker = chars[i];
7457− if let Some(end) = find_closing_single(&chars, i + 1, marker) {
7458− let inner: String = chars[i + 1..end].iter().collect();
7459− result.push_str("<em>");
7460− result.push_str(&md_inline(&inner));
7461− result.push_str("</em>");
7466− // Inline code: `text`
7468− && let Some(end) = chars[i + 1..].iter().position(|&c| c == '`')
7470− let inner: String = chars[i + 1..i + 1 + end].iter().collect();
7471− result.push_str("<code>");
7472− result.push_str(&html_escape_md(&inner));
7473− result.push_str("</code>");
7477− // Links: [text](url)
7479− && let Some(close_bracket) = chars[i + 1..].iter().position(|&c| c == ']')
7481− let after = i + 1 + close_bracket + 1;
7482− if after < chars.len()
7483− && chars[after] == '('
7484− && let Some(close_paren) = chars[after + 1..].iter().position(|&c| c == ')')
7486− let text: String = chars[i + 1..i + 1 + close_bracket].iter().collect();
7487− let url: String = chars[after + 1..after + 1 + close_paren].iter().collect();
7488− result.push_str(&format!(
7489− "<a href=\"{}\">{}</a>",
7490− html_escape_md(&url),
7493− i = after + 2 + close_paren;
7497− result.push(chars[i]);
7504−fn find_closing_double(chars: &[char], start: usize, marker: char) -> Option<usize> {
7506− while i + 1 < chars.len() {
7507− if chars[i] == marker && chars[i + 1] == marker {
7515−fn find_closing_single(chars: &[char], start: usize, marker: char) -> Option<usize> {
7516− (start..chars.len()).find(|&i| chars[i] == marker)
7519−/// Simple glob matching supporting `*` as wildcard for any characters and `?` for a single character.
7520−fn glob_match(pattern: &str, text: &str) -> bool {
7523− let pb = pattern.as_bytes();
7524− let tb = text.as_bytes();
7525− let mut star_pi = usize::MAX;
7526− let mut star_ti = 0;
7527− while ti < tb.len() {
7528− if pi < pb.len() && (pb[pi] == b'?' || pb[pi] == tb[ti]) {
7531− } else if pi < pb.len() && pb[pi] == b'*' {
7535− } else if star_pi != usize::MAX {
7543− while pi < pb.len() && pb[pi] == b'*' {
7549−fn html_escape_md(s: &str) -> String {
7550− s.replace('&', "&")
7551− .replace('<', "<")
7552− .replace('>', ">")
7553− .replace('"', """)
7560− fn parse_ok(src: &str) -> ParseResult {
7561− let r = parse(src);
7563− r.diagnostics.iter().all(|d| d.severity != Severity::Error),
7564− "unexpected error diagnostics: {:?}",
7571− fn parses_empty_input() {
7573− assert!(r.document.nodes.is_empty());
7574− assert!(r.diagnostics.is_empty());
7578− fn parses_bare_text_node() {
7579− let r = parse_ok("Hello world\n");
7580− assert_eq!(r.document.nodes.len(), 1);
7584− fn parses_page_directive() {
7585− let r = parse_ok("@page My Title\n");
7587− r.document.page.map(|p| p.title).as_deref(),
7593− fn let_variable_substitution() {
7594− let r = parse_ok("@let color red\n@text [color $color] hi\n");
7596− r.document.variables.get("color").map(|s| s.as_str()),
7602− fn error_recovery_continues_after_unknown_element() {
7603− // Intentionally malformed line followed by a valid one — recovery must
7604− // let us still see the good line in diagnostics / output.
7605− let r = parse("@notareal\n@text hi\n");
7606− let has_error = r.diagnostics.iter().any(|d| d.severity == Severity::Error);
7607− assert!(has_error, "expected at least one error for @notareal");
7611− fn undefined_fn_is_reported_not_panics() {
7612− // Prior to the unwrap fix this panicked.
7613− let r = parse("@missing\n");
7614− assert!(r.diagnostics.iter().any(|d| d.severity == Severity::Error));
7618− fn scope_without_selector_does_not_panic() {
7619− let r = parse("@scope\n body { background red; }\n");
7620− // Should parse — may or may not emit diagnostics, but must not panic.
7625− fn levenshtein_bounded_respects_cutoff() {
7626− let a: Vec<char> = "hello".chars().collect();
7627− let b: Vec<char> = "world".chars().collect();
7628− // Full distance is 4, but asking for cutoff 2 should early-exit.
7629− let d = levenshtein_bounded(&a, &b, 2);
7630− assert!(d > 2, "expected early exit above cutoff, got {}", d);
7634− fn severity_has_all_variants() {
7635− // This compiles only if Severity has Error, Warning, Info, Help.
7642− assert_eq!(all.len(), 4);
7646− fn arithmetic_empty_operator_does_not_panic() {
7647− // Guards the `op.trim().chars().next().unwrap()` fix.
7648− let r = parse("@let x = 1 + 2\n");
7649− assert_eq!(r.document.variables.get("x").map(|s| s.as_str()), Some("3"));