mirror of
https://github.com/HigherOrderCO/Bend.git
synced 2024-09-17 14:47:21 +03:00
[sc-548] Refactor parser a bit
This commit is contained in:
parent
39ff4ffb7e
commit
ba748c95e8
@ -132,222 +132,252 @@ impl<'a> TermParser<'a> {
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fn parse_pattern(&mut self, simple: bool) -> Result<Pattern, String> {
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maybe_grow(|| {
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let (tag, unexpected_tag) = self.parse_tag()?;
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let Some(head) = self.skip_peek_one() else { return self.expected("pattern-matching pattern") };
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let pat = match head {
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// Ctr or Tup
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'(' => {
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self.consume("(")?;
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let head_ini_idx = *self.index();
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let head = self.parse_pattern(simple)?;
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let head_end_idx = *self.index();
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self.skip_trivia();
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if simple || self.skip_starts_with(",") {
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self.consume(",")?;
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// Tup
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let mut els = self.list_like(|p| p.parse_pattern(simple), "", ")", ",", true, 1)?;
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els.insert(0, head);
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Pattern::Fan(FanKind::Tup, tag.unwrap_or(Tag::Static), els)
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} else {
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unexpected_tag(self)?;
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// Ctr
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let Pattern::Var(Some(name)) = head else {
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return self.expected_spanned("constructor name", head_ini_idx, head_end_idx);
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};
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let els = self.list_like(|p| p.parse_pattern(simple), "", ")", "", false, 0)?;
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Pattern::Ctr(name, els)
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}
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// Ctr or Tup
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if self.starts_with("(") {
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self.consume("(")?;
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let head_ini_idx = *self.index();
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let head = self.parse_pattern(simple)?;
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let head_end_idx = *self.index();
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// Tup
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if simple || self.skip_starts_with(",") {
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self.consume(",")?;
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let mut els = self.list_like(|p| p.parse_pattern(simple), "", ")", ",", true, 1)?;
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els.insert(0, head);
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return Ok(Pattern::Fan(FanKind::Tup, tag.unwrap_or(Tag::Static), els));
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}
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// Dup
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'{' => {
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let els = self.list_like(|p| p.parse_pattern(simple), "{", "}", "", false, 0)?;
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Pattern::Fan(FanKind::Dup, tag.unwrap_or(Tag::Auto), els)
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}
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// List
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'[' if !simple => {
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unexpected_tag(self)?;
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let els = self.list_like(|p| p.parse_pattern(simple), "[", "]", ",", false, 0)?;
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Pattern::Lst(els)
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}
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// String
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'\"' if !simple => {
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unexpected_tag(self)?;
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let str = self.parse_quoted_string()?;
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Pattern::Str(STRINGS.get(str))
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}
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// Char
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'\'' => {
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unexpected_tag(self)?;
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let char = self.parse_quoted_char()?;
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Pattern::Num(char as u32)
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}
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// Number
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c if c.is_ascii_digit() => {
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unexpected_tag(self)?;
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let num = self.parse_u64()?;
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Pattern::Num(num as u32)
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}
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// Channel
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'$' => {
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unexpected_tag(self)?;
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self.advance_one();
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let name = self.parse_hvml_name()?;
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Pattern::Chn(name)
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}
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// Var
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_ => {
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unexpected_tag(self)?;
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let name = self.parse_name_or_era()?;
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Pattern::Var(name)
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}
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};
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Ok(pat)
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// Ctr
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unexpected_tag(self)?;
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let Pattern::Var(Some(name)) = head else {
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return self.expected_spanned("constructor name", head_ini_idx, head_end_idx);
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};
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let els = self.list_like(|p| p.parse_pattern(simple), "", ")", "", false, 0)?;
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return Ok(Pattern::Ctr(name, els));
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}
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// Dup
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if self.starts_with("{") {
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let els = self.list_like(|p| p.parse_pattern(simple), "{", "}", ",", false, 0)?;
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return Ok(Pattern::Fan(FanKind::Dup, tag.unwrap_or(Tag::Auto), els));
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}
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// List
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if self.starts_with("[") && !simple {
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unexpected_tag(self)?;
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let els = self.list_like(|p| p.parse_pattern(simple), "[", "]", ",", false, 0)?;
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return Ok(Pattern::Lst(els));
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}
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// String
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if self.starts_with("\"") && !simple {
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unexpected_tag(self)?;
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let str = self.parse_quoted_string()?;
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return Ok(Pattern::Str(STRINGS.get(str)));
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}
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// Char
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if self.starts_with("'") {
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unexpected_tag(self)?;
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let char = self.parse_quoted_char()?;
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return Ok(Pattern::Num(char as u32));
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}
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// Number
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if self.peek_one().map_or(false, |c| c.is_ascii_digit()) {
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unexpected_tag(self)?;
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let num = self.parse_u64()?;
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return Ok(Pattern::Num(num as u32));
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}
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// Channel
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if self.starts_with("$") {
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unexpected_tag(self)?;
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self.advance_one();
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let name = self.parse_hvml_name()?;
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return Ok(Pattern::Chn(name));
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}
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// Var
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unexpected_tag(self)?;
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let nam = self.labelled(|p| p.parse_name_or_era(), "pattern-matching pattern")?;
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Ok(Pattern::Var(nam))
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})
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}
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pub fn parse_term(&mut self) -> Result<Term, String> {
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maybe_grow(|| {
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let (tag, unexpected_tag) = self.parse_tag()?;
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let Some(head) = self.skip_peek_one() else { return self.expected("term") };
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let term = match head {
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// Lambda, unscoped lambda
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'λ' | '@' => {
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let tag = tag.unwrap_or(Tag::Static);
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self.advance_one().unwrap();
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let pat = self.parse_pattern(true)?;
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let bod = self.parse_term()?;
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Term::Lam { tag, pat: Box::new(pat), bod: Box::new(bod) }
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}
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// App, Tup, Num Op
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'(' => {
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self.consume("(")?;
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let starts_with_oper = self.skip_peek_one().map_or(false, |c| "+-*/%&|<>^=!".contains(c));
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if starts_with_oper {
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let opr = self.parse_oper()?;
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if self.skip_starts_with(",") && opr == Op::MUL {
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// jk, actually a tuple
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let mut els = vec![Term::Era];
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while self.try_consume(",") {
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els.push(self.parse_term()?);
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}
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self.consume(")")?;
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Term::Fan { fan: FanKind::Tup, tag: tag.unwrap_or(Tag::Static), els }
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} else {
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unexpected_tag(self)?;
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let fst = self.parse_term()?;
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let snd = self.parse_term()?;
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self.consume(")")?;
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Term::Opr { opr, fst: Box::new(fst), snd: Box::new(snd) }
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}
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} else {
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// Tup or App
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let head = self.parse_term()?;
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if self.skip_starts_with(",") {
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// Tup
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let mut els = vec![head];
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while self.try_consume(",") {
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els.push(self.parse_term()?);
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}
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self.consume(")")?;
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Term::Fan { fan: FanKind::Tup, tag: tag.unwrap_or(Tag::Static), els }
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} else {
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// App
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let els = self.list_like(|p| p.parse_term(), "", ")", "", false, 0)?;
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els.into_iter().fold(head, |fun, arg| Term::App {
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tag: tag.clone().unwrap_or(Tag::Static),
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fun: Box::new(fun),
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arg: Box::new(arg),
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})
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self.skip_trivia();
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// Lambda, unscoped lambda
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if self.starts_with("λ") || self.starts_with("@") {
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self.advance_one().unwrap();
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let tag = tag.unwrap_or(Tag::Static);
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let pat = self.parse_pattern(true)?;
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let bod = self.parse_term()?;
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return Ok(Term::Lam { tag, pat: Box::new(pat), bod: Box::new(bod) });
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}
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// App, Tup, Num Op
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if self.starts_with("(") {
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self.consume("(")?;
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// Opr but maybe a tup
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let starts_with_oper = self.skip_peek_one().map_or(false, |c| "+-*/%&|<>^=!".contains(c));
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if starts_with_oper {
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let opr = self.parse_oper()?;
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// jk, actually a tuple
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if self.skip_starts_with(",") && opr == Op::MUL {
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let mut els = vec![Term::Era];
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while self.try_consume(",") {
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els.push(self.parse_term()?);
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}
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self.consume(")")?;
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return Ok(Term::Fan { fan: FanKind::Tup, tag: tag.unwrap_or(Tag::Static), els });
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}
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}
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// List
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'[' => {
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// Opr
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unexpected_tag(self)?;
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let els = self.list_like(|p| p.parse_term(), "[", "]", ",", false, 0)?;
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Term::Lst { els }
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let fst = self.parse_term()?;
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let snd = self.parse_term()?;
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self.consume(")")?;
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return Ok(Term::Opr { opr, fst: Box::new(fst), snd: Box::new(snd) });
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}
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// Sup
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'{' => {
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let els = self.list_like(|p| p.parse_term(), "{", "}", ",", false, 2)?;
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Term::Fan { fan: FanKind::Dup, tag: tag.unwrap_or(Tag::Auto), els }
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}
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// Unscoped var
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'$' => {
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unexpected_tag(self)?;
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self.consume("$")?;
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let nam = self.parse_hvml_name()?;
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Term::Lnk { nam }
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}
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// Era
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'*' => {
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unexpected_tag(self)?;
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self.consume("*")?;
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Term::Era
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}
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// Nat, tagged lambda, tagged sup, tagged app
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'#' => {
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unexpected_tag(self)?;
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self.consume("#")?;
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let val = self.parse_u64()?;
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Term::Nat { val }
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}
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// String
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'"' => {
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unexpected_tag(self)?;
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let val = self.parse_quoted_string()?;
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Term::Str { val: STRINGS.get(val) }
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}
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// Char
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'\'' => {
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unexpected_tag(self)?;
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let chr = self.parse_quoted_char()?;
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Term::Num { typ: NumType::U24, val: chr as u32 }
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}
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// Native num
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c if c.is_ascii_digit() => {
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unexpected_tag(self)?;
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let val = self.parse_u64()?;
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Term::Num { typ: NumType::U24, val: val as u32 }
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}
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_ => {
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unexpected_tag(self)?;
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if self.try_consume_keyword("use") {
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// Use
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let nam = self.parse_hvml_name()?;
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self.consume("=")?;
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let val = self.parse_term()?;
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self.try_consume(";");
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let nxt = self.parse_term()?;
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Term::Use { nam: Some(nam), val: Box::new(val), nxt: Box::new(nxt) }
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} else if self.try_consume_keyword("let") {
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let pat = self.parse_pattern(true)?;
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self.consume("=")?;
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let val = self.parse_term()?;
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self.try_consume(";");
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let nxt = self.parse_term()?;
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Term::Let { pat: Box::new(pat), val: Box::new(val), nxt: Box::new(nxt) }
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} else if self.try_consume_keyword("match") {
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// match
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let (bnd, arg, with) = self.parse_match_arg()?;
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let rules = self.list_like(|p| p.parse_match_arm(), "{", "}", ";", false, 1)?;
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Term::Mat { arg: Box::new(arg), bnd: Some(bnd), with, arms: rules }
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} else if self.try_consume_keyword("switch") {
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// switch
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self.parse_switch()?
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} else if self.try_consume_keyword("do") {
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let fun = self.parse_name()?;
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self.consume("{")?;
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let ask = self.parse_ask(Name::new(fun))?;
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self.consume("}")?;
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ask
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} else {
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// var
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let nam = self.labelled(|p| p.parse_hvml_name(), "term")?;
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Term::Var { nam }
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// Tup or App
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let head = self.parse_term()?;
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// Tup
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if self.skip_starts_with(",") {
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let mut els = vec![head];
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while self.try_consume(",") {
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els.push(self.parse_term()?);
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}
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self.consume(")")?;
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return Ok(Term::Fan { fan: FanKind::Tup, tag: tag.unwrap_or(Tag::Static), els });
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}
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};
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Ok(term)
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// App
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let els = self.list_like(|p| p.parse_term(), "", ")", "", false, 0)?;
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let term = els.into_iter().fold(head, |fun, arg| Term::App {
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tag: tag.clone().unwrap_or(Tag::Static),
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fun: Box::new(fun),
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arg: Box::new(arg),
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});
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return Ok(term);
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}
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// List
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if self.starts_with("[") {
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unexpected_tag(self)?;
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let els = self.list_like(|p| p.parse_term(), "[", "]", ",", false, 0)?;
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return Ok(Term::Lst { els });
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}
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// Sup
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if self.starts_with("{") {
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let els = self.list_like(|p| p.parse_term(), "{", "}", ",", false, 2)?;
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return Ok(Term::Fan { fan: FanKind::Dup, tag: tag.unwrap_or(Tag::Auto), els });
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}
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// Unscoped var
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if self.starts_with("$") {
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self.consume("$")?;
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unexpected_tag(self)?;
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let nam = self.parse_hvml_name()?;
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return Ok(Term::Lnk { nam });
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}
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// Era
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if self.starts_with("*") {
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self.consume("*")?;
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unexpected_tag(self)?;
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return Ok(Term::Era);
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}
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// Nat
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if self.starts_with("#") {
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self.consume("#")?;
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unexpected_tag(self)?;
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let val = self.parse_u64()?;
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return Ok(Term::Nat { val });
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}
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// String
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if self.starts_with("\"") {
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unexpected_tag(self)?;
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let str = self.parse_quoted_string()?;
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return Ok(Term::Str { val: STRINGS.get(str) });
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}
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// Char
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if self.starts_with("'") {
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unexpected_tag(self)?;
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let char = self.parse_quoted_char()?;
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return Ok(Term::Num { typ: NumType::U24, val: char as u32 });
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}
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// Native num
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if self.peek_one().map_or(false, |c| c.is_ascii_digit()) {
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unexpected_tag(self)?;
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let val = self.parse_u64()?;
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return Ok(Term::Num { typ: NumType::U24, val: val as u32 });
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}
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// Use
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if self.try_consume_keyword("use") {
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unexpected_tag(self)?;
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let nam = self.parse_hvml_name()?;
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self.consume("=")?;
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let val = self.parse_term()?;
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self.try_consume(";");
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let nxt = self.parse_term()?;
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return Ok(Term::Use { nam: Some(nam), val: Box::new(val), nxt: Box::new(nxt) });
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}
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// Let
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if self.try_consume_keyword("let") {
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unexpected_tag(self)?;
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let pat = self.parse_pattern(true)?;
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self.consume("=")?;
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let val = self.parse_term()?;
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self.try_consume(";");
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let nxt = self.parse_term()?;
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return Ok(Term::Let { pat: Box::new(pat), val: Box::new(val), nxt: Box::new(nxt) });
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}
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// Match
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if self.try_consume_keyword("match") {
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unexpected_tag(self)?;
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let (bnd, arg, with) = self.parse_match_arg()?;
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let rules = self.list_like(|p| p.parse_match_arm(), "{", "}", ";", false, 1)?;
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return Ok(Term::Mat { arg: Box::new(arg), bnd: Some(bnd), with, arms: rules });
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}
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// Switch
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if self.try_consume_keyword("switch") {
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unexpected_tag(self)?;
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return self.parse_switch();
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}
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// Do
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if self.try_consume_keyword("do") {
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unexpected_tag(self)?;
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let fun = self.parse_name()?;
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self.consume("{")?;
|
||||
let ask = self.parse_ask(Name::new(fun))?;
|
||||
self.consume("}")?;
|
||||
return Ok(ask);
|
||||
}
|
||||
|
||||
// Var
|
||||
unexpected_tag(self)?;
|
||||
let nam = self.labelled(|p| p.parse_hvml_name(), "term")?;
|
||||
Ok(Term::Var { nam })
|
||||
})
|
||||
}
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user