use {SyntaxKind, TextUnit, Token}; use super::Event; use super::super::is_insignificant; use SyntaxKind::{EOF, ERROR, L_CURLY, R_CURLY, TOMBSTONE}; pub(crate) struct Marker { pos: u32, } impl Marker { pub fn complete(self, p: &mut Parser, kind: SyntaxKind) -> CompleteMarker { match self.event(p) { &mut Event::Start { kind: ref mut slot, .. } => { *slot = kind; } _ => unreachable!(), } p.event(Event::Finish); let result = CompleteMarker { pos: self.pos }; ::std::mem::forget(self); result } pub fn abandon(self, p: &mut Parser) { let idx = self.pos as usize; if idx == p.events.len() - 1 { match p.events.pop() { Some(Event::Start { kind: TOMBSTONE, forward_parent: None, }) => (), _ => unreachable!(), } } ::std::mem::forget(self); } fn event<'p>(&self, p: &'p mut Parser) -> &'p mut Event { &mut p.events[self.idx()] } fn idx(&self) -> usize { self.pos as usize } } impl Drop for Marker { fn drop(&mut self) { if !::std::thread::panicking() { panic!("Each marker should be eithe completed or abandoned"); } } } pub(crate) struct CompleteMarker { pos: u32, } impl CompleteMarker { pub(crate) fn precede(self, p: &mut Parser) -> Marker { let m = p.start(); match p.events[self.pos as usize] { Event::Start { ref mut forward_parent, .. } => { *forward_parent = Some(m.pos - self.pos); } _ => unreachable!(), } m } } pub(crate) struct TokenSet { pub tokens: &'static [SyntaxKind], } impl TokenSet { pub fn contains(&self, kind: SyntaxKind) -> bool { self.tokens.contains(&kind) } } #[macro_export] macro_rules! token_set { ($($t:ident),*) => { TokenSet { tokens: &[$($t),*], } }; ($($t:ident),* ,) => { token_set!($($t),*) }; } pub(crate) struct Parser<'t> { #[allow(unused)] text: &'t str, #[allow(unused)] start_offsets: Vec, tokens: Vec, // non-whitespace tokens pos: usize, events: Vec, curly_level: i32, curly_limit: Option, } impl<'t> Parser<'t> { pub(crate) fn new(text: &'t str, raw_tokens: &'t [Token]) -> Parser<'t> { let mut tokens = Vec::new(); let mut start_offsets = Vec::new(); let mut len = TextUnit::new(0); for &token in raw_tokens.iter() { if !is_insignificant(token.kind) { tokens.push(token); start_offsets.push(len); } len += token.len; } Parser { text, start_offsets, tokens, pos: 0, events: Vec::new(), curly_level: 0, curly_limit: None, } } pub(crate) fn into_events(self) -> Vec { assert!(self.curly_limit.is_none()); assert_eq!(self.current(), EOF); self.events } pub(crate) fn current(&self) -> SyntaxKind { if self.pos == self.tokens.len() { return EOF; } let token = self.tokens[self.pos]; if let Some(limit) = self.curly_limit { if limit == self.curly_level && token.kind == R_CURLY { return EOF; } } token.kind } pub(crate) fn start(&mut self) -> Marker { let m = Marker { pos: self.events.len() as u32, }; self.event(Event::Start { kind: TOMBSTONE, forward_parent: None, }); m } pub(crate) fn error<'p>(&'p mut self) -> ErrorBuilder<'p, 't> { ErrorBuilder::new(self) } pub(crate) fn bump(&mut self) -> SyntaxKind { let kind = self.current(); match kind { L_CURLY => self.curly_level += 1, R_CURLY => self.curly_level -= 1, EOF => return EOF, _ => (), } self.pos += 1; self.event(Event::Token { kind, n_raw_tokens: 1, }); kind } pub(crate) fn raw_lookahead(&self, n: usize) -> SyntaxKind { self.tokens.get(self.pos + n).map(|t| t.kind).unwrap_or(EOF) } pub(crate) fn curly_block(&mut self, f: F) -> bool { let old_level = self.curly_level; let old_limit = self.curly_limit; if !self.expect(L_CURLY) { return false; } self.curly_limit = Some(self.curly_level); f(self); assert!(self.curly_level > old_level); self.curly_limit = old_limit; if !self.expect(R_CURLY) { let err = self.start(); while self.curly_level > old_level { if self.bump() == EOF { break; } } err.complete(self, ERROR); } true } fn event(&mut self, event: Event) { self.events.push(event) } } pub(crate) struct ErrorBuilder<'p, 't: 'p> { message: Option, parser: &'p mut Parser<'t>, } impl<'t, 'p> ErrorBuilder<'p, 't> { fn new(parser: &'p mut Parser<'t>) -> Self { ErrorBuilder { message: None, parser, } } pub fn message>(mut self, m: M) -> Self { self.message = Some(m.into()); self } pub fn emit(self) { let message = self.message.expect("Error message not set"); self.parser.event(Event::Error { message }); } }