diff --git a/crates/mbe/src/lib.rs b/crates/mbe/src/lib.rs index 1a56878fdb5..5e14a3fb590 100644 --- a/crates/mbe/src/lib.rs +++ b/crates/mbe/src/lib.rs @@ -10,7 +10,7 @@ mod expander; mod syntax_bridge; mod tt_iter; -mod to_parser_tokens; +mod to_parser_input; #[cfg(test)] mod benchmark; diff --git a/crates/mbe/src/syntax_bridge.rs b/crates/mbe/src/syntax_bridge.rs index 109842b0cd0..f0c1f806ffa 100644 --- a/crates/mbe/src/syntax_bridge.rs +++ b/crates/mbe/src/syntax_bridge.rs @@ -1,6 +1,5 @@ //! Conversions between [`SyntaxNode`] and [`tt::TokenTree`]. -use parser::{ParseError, TreeSink}; use rustc_hash::{FxHashMap, FxHashSet}; use syntax::{ ast::{self, make::tokens::doc_comment}, @@ -11,7 +10,7 @@ use tt::buffer::{Cursor, TokenBuffer}; use crate::{ - to_parser_tokens::to_parser_tokens, tt_iter::TtIter, ExpandError, ParserEntryPoint, TokenMap, + to_parser_input::to_parser_input, tt_iter::TtIter, ExpandError, ParserEntryPoint, TokenMap, }; /// Convert the syntax node to a `TokenTree` (what macro @@ -55,9 +54,19 @@ pub fn token_tree_to_syntax_node( } _ => TokenBuffer::from_subtree(tt), }; - let parser_tokens = to_parser_tokens(&buffer); + let parser_input = to_parser_input(&buffer); + let parser_output = parser::parse(&parser_input, entry_point); let mut tree_sink = TtTreeSink::new(buffer.begin()); - parser::parse(&parser_tokens, &mut tree_sink, entry_point); + for event in parser_output.iter() { + match event { + parser::Step::Token { kind, n_input_tokens: n_raw_tokens } => { + tree_sink.token(kind, n_raw_tokens) + } + parser::Step::Enter { kind } => tree_sink.start_node(kind), + parser::Step::Exit => tree_sink.finish_node(), + parser::Step::Error { msg } => tree_sink.error(msg.to_string()), + } + } if tree_sink.roots.len() != 1 { return Err(ExpandError::ConversionError); } @@ -643,7 +652,7 @@ fn delim_to_str(d: tt::DelimiterKind, closing: bool) -> &'static str { &texts[idx..texts.len() - (1 - idx)] } -impl<'a> TreeSink for TtTreeSink<'a> { +impl<'a> TtTreeSink<'a> { fn token(&mut self, kind: SyntaxKind, mut n_tokens: u8) { if kind == LIFETIME_IDENT { n_tokens = 2; @@ -741,7 +750,7 @@ fn finish_node(&mut self) { *self.roots.last_mut().unwrap() -= 1; } - fn error(&mut self, error: ParseError) { + fn error(&mut self, error: String) { self.inner.error(error, self.text_pos) } } diff --git a/crates/mbe/src/to_parser_tokens.rs b/crates/mbe/src/to_parser_input.rs similarity index 97% rename from crates/mbe/src/to_parser_tokens.rs rename to crates/mbe/src/to_parser_input.rs index f419c78d46c..6faa147218e 100644 --- a/crates/mbe/src/to_parser_tokens.rs +++ b/crates/mbe/src/to_parser_input.rs @@ -4,8 +4,8 @@ use syntax::{SyntaxKind, SyntaxKind::*, T}; use tt::buffer::TokenBuffer; -pub(crate) fn to_parser_tokens(buffer: &TokenBuffer) -> parser::Tokens { - let mut res = parser::Tokens::default(); +pub(crate) fn to_parser_input(buffer: &TokenBuffer) -> parser::Input { + let mut res = parser::Input::default(); let mut current = buffer.begin(); diff --git a/crates/mbe/src/tt_iter.rs b/crates/mbe/src/tt_iter.rs index d05e84b0f02..2d2dbd8994f 100644 --- a/crates/mbe/src/tt_iter.rs +++ b/crates/mbe/src/tt_iter.rs @@ -1,11 +1,10 @@ //! A "Parser" structure for token trees. We use this when parsing a declarative //! macro definition into a list of patterns and templates. -use crate::{to_parser_tokens::to_parser_tokens, ExpandError, ExpandResult, ParserEntryPoint}; +use crate::{to_parser_input::to_parser_input, ExpandError, ExpandResult, ParserEntryPoint}; -use parser::TreeSink; use syntax::SyntaxKind; -use tt::buffer::{Cursor, TokenBuffer}; +use tt::buffer::TokenBuffer; macro_rules! err { () => { @@ -94,34 +93,28 @@ pub(crate) fn expect_fragment( &mut self, entry_point: ParserEntryPoint, ) -> ExpandResult> { - struct OffsetTokenSink<'a> { - cursor: Cursor<'a>, - error: bool, - } - - impl<'a> TreeSink for OffsetTokenSink<'a> { - fn token(&mut self, kind: SyntaxKind, mut n_tokens: u8) { - if kind == SyntaxKind::LIFETIME_IDENT { - n_tokens = 2; - } - for _ in 0..n_tokens { - self.cursor = self.cursor.bump_subtree(); - } - } - fn start_node(&mut self, _kind: SyntaxKind) {} - fn finish_node(&mut self) {} - fn error(&mut self, _error: parser::ParseError) { - self.error = true; - } - } - let buffer = TokenBuffer::from_tokens(self.inner.as_slice()); - let parser_tokens = to_parser_tokens(&buffer); - let mut sink = OffsetTokenSink { cursor: buffer.begin(), error: false }; + let parser_input = to_parser_input(&buffer); + let tree_traversal = parser::parse(&parser_input, entry_point); - parser::parse(&parser_tokens, &mut sink, entry_point); + let mut cursor = buffer.begin(); + let mut error = false; + for step in tree_traversal.iter() { + match step { + parser::Step::Token { kind, mut n_input_tokens } => { + if kind == SyntaxKind::LIFETIME_IDENT { + n_input_tokens = 2; + } + for _ in 0..n_input_tokens { + cursor = cursor.bump_subtree(); + } + } + parser::Step::Enter { .. } | parser::Step::Exit => (), + parser::Step::Error { .. } => error = true, + } + } - let mut err = if !sink.cursor.is_root() || sink.error { + let mut err = if !cursor.is_root() || error { Some(err!("expected {:?}", entry_point)) } else { None @@ -130,8 +123,8 @@ fn error(&mut self, _error: parser::ParseError) { let mut curr = buffer.begin(); let mut res = vec![]; - if sink.cursor.is_root() { - while curr != sink.cursor { + if cursor.is_root() { + while curr != cursor { if let Some(token) = curr.token_tree() { res.push(token); } diff --git a/crates/parser/src/event.rs b/crates/parser/src/event.rs index 41b0328027c..b0e70e79430 100644 --- a/crates/parser/src/event.rs +++ b/crates/parser/src/event.rs @@ -10,9 +10,8 @@ use std::mem; use crate::{ - ParseError, + output::Output, SyntaxKind::{self, *}, - TreeSink, }; /// `Parser` produces a flat list of `Event`s. @@ -77,7 +76,7 @@ pub(crate) enum Event { }, Error { - msg: ParseError, + msg: String, }, } @@ -88,7 +87,8 @@ pub(crate) fn tombstone() -> Self { } /// Generate the syntax tree with the control of events. -pub(super) fn process(sink: &mut dyn TreeSink, mut events: Vec) { +pub(super) fn process(mut events: Vec) -> Output { + let mut res = Output::default(); let mut forward_parents = Vec::new(); for i in 0..events.len() { @@ -117,15 +117,17 @@ pub(super) fn process(sink: &mut dyn TreeSink, mut events: Vec) { for kind in forward_parents.drain(..).rev() { if kind != TOMBSTONE { - sink.start_node(kind); + res.enter_node(kind); } } } - Event::Finish => sink.finish_node(), + Event::Finish => res.leave_node(), Event::Token { kind, n_raw_tokens } => { - sink.token(kind, n_raw_tokens); + res.token(kind, n_raw_tokens); } - Event::Error { msg } => sink.error(msg), + Event::Error { msg } => res.error(msg), } } + + res } diff --git a/crates/parser/src/tokens.rs b/crates/parser/src/input.rs similarity index 84% rename from crates/parser/src/tokens.rs rename to crates/parser/src/input.rs index 4fc2361add2..9504bd4d9ec 100644 --- a/crates/parser/src/tokens.rs +++ b/crates/parser/src/input.rs @@ -1,26 +1,26 @@ -//! Input for the parser -- a sequence of tokens. -//! -//! As of now, parser doesn't have access to the *text* of the tokens, and makes -//! decisions based solely on their classification. Unlike `LexerToken`, the -//! `Tokens` doesn't include whitespace and comments. +//! See [`Input`]. use crate::SyntaxKind; #[allow(non_camel_case_types)] type bits = u64; -/// Main input to the parser. +/// Input for the parser -- a sequence of tokens. /// -/// A sequence of tokens represented internally as a struct of arrays. +/// As of now, parser doesn't have access to the *text* of the tokens, and makes +/// decisions based solely on their classification. Unlike `LexerToken`, the +/// `Tokens` doesn't include whitespace and comments. Main input to the parser. +/// +/// Struct of arrays internally, but this shouldn't really matter. #[derive(Default)] -pub struct Tokens { +pub struct Input { kind: Vec, joint: Vec, contextual_kind: Vec, } /// `pub` impl used by callers to create `Tokens`. -impl Tokens { +impl Input { #[inline] pub fn push(&mut self, kind: SyntaxKind) { self.push_impl(kind, SyntaxKind::EOF) @@ -63,7 +63,7 @@ fn push_impl(&mut self, kind: SyntaxKind, contextual_kind: SyntaxKind) { } /// pub(crate) impl used by the parser to consume `Tokens`. -impl Tokens { +impl Input { pub(crate) fn kind(&self, idx: usize) -> SyntaxKind { self.kind.get(idx).copied().unwrap_or(SyntaxKind::EOF) } @@ -76,7 +76,7 @@ pub(crate) fn is_joint(&self, n: usize) -> bool { } } -impl Tokens { +impl Input { fn bit_index(&self, n: usize) -> (usize, usize) { let idx = n / (bits::BITS as usize); let b_idx = n % (bits::BITS as usize); diff --git a/crates/parser/src/lexed_str.rs b/crates/parser/src/lexed_str.rs index b8936c34403..f17aae1d314 100644 --- a/crates/parser/src/lexed_str.rs +++ b/crates/parser/src/lexed_str.rs @@ -122,8 +122,8 @@ pub fn errors(&self) -> impl Iterator + '_ { self.error.iter().map(|it| (it.token as usize, it.msg.as_str())) } - pub fn to_tokens(&self) -> crate::Tokens { - let mut res = crate::Tokens::default(); + pub fn to_input(&self) -> crate::Input { + let mut res = crate::Input::default(); let mut was_joint = false; for i in 0..self.len() { let kind = self.kind(i); diff --git a/crates/parser/src/lib.rs b/crates/parser/src/lib.rs index dc02ae6e83f..da78889f350 100644 --- a/crates/parser/src/lib.rs +++ b/crates/parser/src/lib.rs @@ -24,32 +24,20 @@ mod event; mod parser; mod grammar; -mod tokens; +mod input; +mod output; #[cfg(test)] mod tests; pub(crate) use token_set::TokenSet; -pub use crate::{lexed_str::LexedStr, syntax_kind::SyntaxKind, tokens::Tokens}; - -#[derive(Debug, Clone, PartialEq, Eq, Hash)] -pub struct ParseError(pub Box); - -/// `TreeSink` abstracts details of a particular syntax tree implementation. -pub trait TreeSink { - /// Adds new token to the current branch. - fn token(&mut self, kind: SyntaxKind, n_tokens: u8); - - /// Start new branch and make it current. - fn start_node(&mut self, kind: SyntaxKind); - - /// Finish current branch and restore previous - /// branch as current. - fn finish_node(&mut self); - - fn error(&mut self, error: ParseError); -} +pub use crate::{ + input::Input, + lexed_str::LexedStr, + output::{Output, Step}, + syntax_kind::SyntaxKind, +}; /// rust-analyzer parser allows you to choose one of the possible entry points. /// @@ -74,11 +62,19 @@ pub enum ParserEntryPoint { } /// Parse given tokens into the given sink as a rust file. -pub fn parse_source_file(tokens: &Tokens, tree_sink: &mut dyn TreeSink) { - parse(tokens, tree_sink, ParserEntryPoint::SourceFile); +pub fn parse_source_file(inp: &Input) -> Output { + parse(inp, ParserEntryPoint::SourceFile) } -pub fn parse(tokens: &Tokens, tree_sink: &mut dyn TreeSink, entry_point: ParserEntryPoint) { +/// Parses the given [`Input`] into [`Output`] assuming that the top-level +/// syntactic construct is the given [`ParserEntryPoint`]. +/// +/// Both input and output here are fairly abstract. The overall flow is that the +/// caller has some "real" tokens, converts them to [`Input`], parses them to +/// [`Output`], and then converts that into a "real" tree. The "real" tree is +/// made of "real" tokens, so this all hinges on rather tight coordination of +/// indices between the four stages. +pub fn parse(inp: &Input, entry_point: ParserEntryPoint) -> Output { let entry_point: fn(&'_ mut parser::Parser) = match entry_point { ParserEntryPoint::SourceFile => grammar::entry_points::source_file, ParserEntryPoint::Path => grammar::entry_points::path, @@ -96,10 +92,10 @@ pub fn parse(tokens: &Tokens, tree_sink: &mut dyn TreeSink, entry_point: ParserE ParserEntryPoint::Attr => grammar::entry_points::attr, }; - let mut p = parser::Parser::new(tokens); + let mut p = parser::Parser::new(inp); entry_point(&mut p); let events = p.finish(); - event::process(tree_sink, events); + event::process(events) } /// A parsing function for a specific braced-block. @@ -119,11 +115,11 @@ pub fn for_node( /// /// Tokens must start with `{`, end with `}` and form a valid brace /// sequence. - pub fn parse(self, tokens: &Tokens, tree_sink: &mut dyn TreeSink) { + pub fn parse(self, tokens: &Input) -> Output { let Reparser(r) = self; let mut p = parser::Parser::new(tokens); r(&mut p); let events = p.finish(); - event::process(tree_sink, events); + event::process(events) } } diff --git a/crates/parser/src/output.rs b/crates/parser/src/output.rs new file mode 100644 index 00000000000..b613df029f8 --- /dev/null +++ b/crates/parser/src/output.rs @@ -0,0 +1,76 @@ +//! See [`Output`] + +use crate::SyntaxKind; + +/// Output of the parser -- a DFS traversal of a concrete syntax tree. +/// +/// Use the [`Output::iter`] method to iterate over traversal steps and consume +/// a syntax tree. +/// +/// In a sense, this is just a sequence of [`SyntaxKind`]-colored parenthesis +/// interspersed into the original [`crate::Input`]. The output is fundamentally +/// coordinated with the input and `n_input_tokens` refers to the number of +/// times [`crate::Input::push`] was called. +#[derive(Default)] +pub struct Output { + /// 32-bit encoding of events. If LSB is zero, then that's an index into the + /// error vector. Otherwise, it's one of the thee other variants, with data encoded as + /// + /// |16 bit kind|8 bit n_input_tokens|4 bit tag|4 bit leftover| + /// + event: Vec, + error: Vec, +} + +pub enum Step<'a> { + Token { kind: SyntaxKind, n_input_tokens: u8 }, + Enter { kind: SyntaxKind }, + Exit, + Error { msg: &'a str }, +} + +impl Output { + pub fn iter(&self) -> impl Iterator> { + self.event.iter().map(|&event| { + if event & 0b1 == 0 { + return Step::Error { msg: self.error[(event as usize) >> 1].as_str() }; + } + let tag = ((event & 0x0000_00F0) >> 4) as u8; + match tag { + 0 => { + let kind: SyntaxKind = (((event & 0xFFFF_0000) >> 16) as u16).into(); + let n_input_tokens = ((event & 0x0000_FF00) >> 8) as u8; + Step::Token { kind, n_input_tokens } + } + 1 => { + let kind: SyntaxKind = (((event & 0xFFFF_0000) >> 16) as u16).into(); + Step::Enter { kind } + } + 2 => Step::Exit, + _ => unreachable!(), + } + }) + } + + pub(crate) fn token(&mut self, kind: SyntaxKind, n_tokens: u8) { + let e = ((kind as u16 as u32) << 16) | ((n_tokens as u32) << 8) | (0 << 4) | 1; + self.event.push(e) + } + + pub(crate) fn enter_node(&mut self, kind: SyntaxKind) { + let e = ((kind as u16 as u32) << 16) | (1 << 4) | 1; + self.event.push(e) + } + + pub(crate) fn leave_node(&mut self) { + let e = 2 << 4 | 1; + self.event.push(e) + } + + pub(crate) fn error(&mut self, error: String) { + let idx = self.error.len(); + self.error.push(error); + let e = (idx as u32) << 1; + self.event.push(e); + } +} diff --git a/crates/parser/src/parser.rs b/crates/parser/src/parser.rs index 4c891108a60..d4aecf9b446 100644 --- a/crates/parser/src/parser.rs +++ b/crates/parser/src/parser.rs @@ -7,8 +7,7 @@ use crate::{ event::Event, - tokens::Tokens, - ParseError, + input::Input, SyntaxKind::{self, EOF, ERROR, TOMBSTONE}, TokenSet, T, }; @@ -23,7 +22,7 @@ /// "start expression, consume number literal, /// finish expression". See `Event` docs for more. pub(crate) struct Parser<'t> { - tokens: &'t Tokens, + inp: &'t Input, pos: usize, events: Vec, steps: Cell, @@ -32,8 +31,8 @@ pub(crate) struct Parser<'t> { static PARSER_STEP_LIMIT: Limit = Limit::new(15_000_000); impl<'t> Parser<'t> { - pub(super) fn new(tokens: &'t Tokens) -> Parser<'t> { - Parser { tokens, pos: 0, events: Vec::new(), steps: Cell::new(0) } + pub(super) fn new(inp: &'t Input) -> Parser<'t> { + Parser { inp, pos: 0, events: Vec::new(), steps: Cell::new(0) } } pub(crate) fn finish(self) -> Vec { @@ -56,7 +55,7 @@ pub(crate) fn nth(&self, n: usize) -> SyntaxKind { assert!(PARSER_STEP_LIMIT.check(steps as usize).is_ok(), "the parser seems stuck"); self.steps.set(steps + 1); - self.tokens.kind(self.pos + n) + self.inp.kind(self.pos + n) } /// Checks if the current token is `kind`. @@ -92,7 +91,7 @@ pub(crate) fn nth_at(&self, n: usize, kind: SyntaxKind) -> bool { T![<<=] => self.at_composite3(n, T![<], T![<], T![=]), T![>>=] => self.at_composite3(n, T![>], T![>], T![=]), - _ => self.tokens.kind(self.pos + n) == kind, + _ => self.inp.kind(self.pos + n) == kind, } } @@ -131,17 +130,17 @@ pub(crate) fn eat(&mut self, kind: SyntaxKind) -> bool { } fn at_composite2(&self, n: usize, k1: SyntaxKind, k2: SyntaxKind) -> bool { - self.tokens.kind(self.pos + n) == k1 - && self.tokens.kind(self.pos + n + 1) == k2 - && self.tokens.is_joint(self.pos + n) + self.inp.kind(self.pos + n) == k1 + && self.inp.kind(self.pos + n + 1) == k2 + && self.inp.is_joint(self.pos + n) } fn at_composite3(&self, n: usize, k1: SyntaxKind, k2: SyntaxKind, k3: SyntaxKind) -> bool { - self.tokens.kind(self.pos + n) == k1 - && self.tokens.kind(self.pos + n + 1) == k2 - && self.tokens.kind(self.pos + n + 2) == k3 - && self.tokens.is_joint(self.pos + n) - && self.tokens.is_joint(self.pos + n + 1) + self.inp.kind(self.pos + n) == k1 + && self.inp.kind(self.pos + n + 1) == k2 + && self.inp.kind(self.pos + n + 2) == k3 + && self.inp.is_joint(self.pos + n) + && self.inp.is_joint(self.pos + n + 1) } /// Checks if the current token is in `kinds`. @@ -151,7 +150,7 @@ pub(crate) fn at_ts(&self, kinds: TokenSet) -> bool { /// Checks if the current token is contextual keyword with text `t`. pub(crate) fn at_contextual_kw(&self, kw: SyntaxKind) -> bool { - self.tokens.contextual_kind(self.pos) == kw + self.inp.contextual_kind(self.pos) == kw } /// Starts a new node in the syntax tree. All nodes and tokens @@ -196,7 +195,7 @@ pub(crate) fn bump_remap(&mut self, kind: SyntaxKind) { /// structured errors with spans and notes, like rustc /// does. pub(crate) fn error>(&mut self, message: T) { - let msg = ParseError(Box::new(message.into())); + let msg = message.into(); self.push_event(Event::Error { msg }); } diff --git a/crates/syntax/src/parsing.rs b/crates/syntax/src/parsing.rs index cba1ddde855..20c7101a032 100644 --- a/crates/syntax/src/parsing.rs +++ b/crates/syntax/src/parsing.rs @@ -4,24 +4,18 @@ mod text_tree_sink; mod reparsing; -use parser::SyntaxKind; -use text_tree_sink::TextTreeSink; - -use crate::{syntax_node::GreenNode, AstNode, SyntaxError, SyntaxNode}; +use crate::{ + parsing::text_tree_sink::build_tree, syntax_node::GreenNode, AstNode, SyntaxError, SyntaxNode, +}; pub(crate) use crate::parsing::reparsing::incremental_reparse; pub(crate) fn parse_text(text: &str) -> (GreenNode, Vec) { let lexed = parser::LexedStr::new(text); - let parser_tokens = lexed.to_tokens(); - - let mut tree_sink = TextTreeSink::new(lexed); - - parser::parse_source_file(&parser_tokens, &mut tree_sink); - - let (tree, parser_errors) = tree_sink.finish(); - - (tree, parser_errors) + let parser_input = lexed.to_input(); + let parser_output = parser::parse_source_file(&parser_input); + let (node, errors, _eof) = build_tree(lexed, parser_output, false); + (node, errors) } /// Returns `text` parsed as a `T` provided there are no parse errors. @@ -33,21 +27,13 @@ pub(crate) fn parse_text_as( if lexed.errors().next().is_some() { return Err(()); } - let parser_tokens = lexed.to_tokens(); + let parser_input = lexed.to_input(); + let parser_output = parser::parse(&parser_input, entry_point); + let (node, errors, eof) = build_tree(lexed, parser_output, true); - let mut tree_sink = TextTreeSink::new(lexed); - - // TextTreeSink assumes that there's at least some root node to which it can attach errors and - // tokens. We arbitrarily give it a SourceFile. - use parser::TreeSink; - tree_sink.start_node(SyntaxKind::SOURCE_FILE); - parser::parse(&parser_tokens, &mut tree_sink, entry_point); - tree_sink.finish_node(); - - let (tree, parser_errors, eof) = tree_sink.finish_eof(); - if !parser_errors.is_empty() || !eof { + if !errors.is_empty() || !eof { return Err(()); } - SyntaxNode::new_root(tree).first_child().and_then(T::cast).ok_or(()) + SyntaxNode::new_root(node).first_child().and_then(T::cast).ok_or(()) } diff --git a/crates/syntax/src/parsing/reparsing.rs b/crates/syntax/src/parsing/reparsing.rs index e9567a838c6..a6abe3cccf3 100644 --- a/crates/syntax/src/parsing/reparsing.rs +++ b/crates/syntax/src/parsing/reparsing.rs @@ -10,7 +10,7 @@ use text_edit::Indel; use crate::{ - parsing::text_tree_sink::TextTreeSink, + parsing::text_tree_sink::build_tree, syntax_node::{GreenNode, GreenToken, NodeOrToken, SyntaxElement, SyntaxNode}, SyntaxError, SyntaxKind::*, @@ -89,16 +89,14 @@ fn reparse_block( let text = get_text_after_edit(node.clone().into(), edit); let lexed = parser::LexedStr::new(text.as_str()); - let parser_tokens = lexed.to_tokens(); + let parser_input = lexed.to_input(); if !is_balanced(&lexed) { return None; } - let mut tree_sink = TextTreeSink::new(lexed); + let tree_traversal = reparser.parse(&parser_input); - reparser.parse(&parser_tokens, &mut tree_sink); - - let (green, new_parser_errors) = tree_sink.finish(); + let (green, new_parser_errors, _eof) = build_tree(lexed, tree_traversal, false); Some((node.replace_with(green), new_parser_errors, node.text_range())) } diff --git a/crates/syntax/src/parsing/text_tree_sink.rs b/crates/syntax/src/parsing/text_tree_sink.rs index c9e7feb9657..f40c549e3d7 100644 --- a/crates/syntax/src/parsing/text_tree_sink.rs +++ b/crates/syntax/src/parsing/text_tree_sink.rs @@ -2,7 +2,7 @@ use std::mem; -use parser::{LexedStr, ParseError, TreeSink}; +use parser::LexedStr; use crate::{ ast, @@ -12,10 +12,37 @@ SyntaxTreeBuilder, TextRange, }; -/// Bridges the parser with our specific syntax tree representation. -/// -/// `TextTreeSink` also handles attachment of trivia (whitespace) to nodes. -pub(crate) struct TextTreeSink<'a> { +pub(crate) fn build_tree( + lexed: LexedStr<'_>, + parser_output: parser::Output, + synthetic_root: bool, +) -> (GreenNode, Vec, bool) { + let mut builder = Builder::new(lexed); + + if synthetic_root { + builder.enter(SyntaxKind::SOURCE_FILE); + } + + for event in parser_output.iter() { + match event { + parser::Step::Token { kind, n_input_tokens: n_raw_tokens } => { + builder.token(kind, n_raw_tokens) + } + parser::Step::Enter { kind } => builder.enter(kind), + parser::Step::Exit => builder.exit(), + parser::Step::Error { msg } => { + let text_pos = builder.lexed.text_start(builder.pos).try_into().unwrap(); + builder.inner.error(msg.to_string(), text_pos); + } + } + } + if synthetic_root { + builder.exit() + } + builder.build() +} + +struct Builder<'a> { lexed: LexedStr<'a>, pos: usize, state: State, @@ -28,61 +55,12 @@ enum State { PendingFinish, } -impl<'a> TreeSink for TextTreeSink<'a> { - fn token(&mut self, kind: SyntaxKind, n_tokens: u8) { - match mem::replace(&mut self.state, State::Normal) { - State::PendingStart => unreachable!(), - State::PendingFinish => self.inner.finish_node(), - State::Normal => (), - } - self.eat_trivias(); - self.do_token(kind, n_tokens as usize); - } - - fn start_node(&mut self, kind: SyntaxKind) { - match mem::replace(&mut self.state, State::Normal) { - State::PendingStart => { - self.inner.start_node(kind); - // No need to attach trivias to previous node: there is no - // previous node. - return; - } - State::PendingFinish => self.inner.finish_node(), - State::Normal => (), - } - - let n_trivias = - (self.pos..self.lexed.len()).take_while(|&it| self.lexed.kind(it).is_trivia()).count(); - let leading_trivias = self.pos..self.pos + n_trivias; - let n_attached_trivias = n_attached_trivias( - kind, - leading_trivias.rev().map(|it| (self.lexed.kind(it), self.lexed.text(it))), - ); - self.eat_n_trivias(n_trivias - n_attached_trivias); - self.inner.start_node(kind); - self.eat_n_trivias(n_attached_trivias); - } - - fn finish_node(&mut self) { - match mem::replace(&mut self.state, State::PendingFinish) { - State::PendingStart => unreachable!(), - State::PendingFinish => self.inner.finish_node(), - State::Normal => (), - } - } - - fn error(&mut self, error: ParseError) { - let text_pos = self.lexed.text_start(self.pos).try_into().unwrap(); - self.inner.error(error, text_pos); - } -} - -impl<'a> TextTreeSink<'a> { - pub(super) fn new(lexed: parser::LexedStr<'a>) -> Self { +impl<'a> Builder<'a> { + fn new(lexed: parser::LexedStr<'a>) -> Self { Self { lexed, pos: 0, state: State::PendingStart, inner: SyntaxTreeBuilder::default() } } - pub(super) fn finish_eof(mut self) -> (GreenNode, Vec, bool) { + fn build(mut self) -> (GreenNode, Vec, bool) { match mem::replace(&mut self.state, State::Normal) { State::PendingFinish => { self.eat_trivias(); @@ -106,9 +84,46 @@ pub(super) fn finish_eof(mut self) -> (GreenNode, Vec, bool) { (node, errors, is_eof) } - pub(super) fn finish(self) -> (GreenNode, Vec) { - let (node, errors, _eof) = self.finish_eof(); - (node, errors) + fn token(&mut self, kind: SyntaxKind, n_tokens: u8) { + match mem::replace(&mut self.state, State::Normal) { + State::PendingStart => unreachable!(), + State::PendingFinish => self.inner.finish_node(), + State::Normal => (), + } + self.eat_trivias(); + self.do_token(kind, n_tokens as usize); + } + + fn enter(&mut self, kind: SyntaxKind) { + match mem::replace(&mut self.state, State::Normal) { + State::PendingStart => { + self.inner.start_node(kind); + // No need to attach trivias to previous node: there is no + // previous node. + return; + } + State::PendingFinish => self.inner.finish_node(), + State::Normal => (), + } + + let n_trivias = + (self.pos..self.lexed.len()).take_while(|&it| self.lexed.kind(it).is_trivia()).count(); + let leading_trivias = self.pos..self.pos + n_trivias; + let n_attached_trivias = n_attached_trivias( + kind, + leading_trivias.rev().map(|it| (self.lexed.kind(it), self.lexed.text(it))), + ); + self.eat_n_trivias(n_trivias - n_attached_trivias); + self.inner.start_node(kind); + self.eat_n_trivias(n_attached_trivias); + } + + fn exit(&mut self) { + match mem::replace(&mut self.state, State::PendingFinish) { + State::PendingStart => unreachable!(), + State::PendingFinish => self.inner.finish_node(), + State::Normal => (), + } } fn eat_trivias(&mut self) { diff --git a/crates/syntax/src/syntax_node.rs b/crates/syntax/src/syntax_node.rs index c95c76c0a8e..b96f10c1730 100644 --- a/crates/syntax/src/syntax_node.rs +++ b/crates/syntax/src/syntax_node.rs @@ -69,7 +69,7 @@ pub fn finish_node(&mut self) { self.inner.finish_node(); } - pub fn error(&mut self, error: parser::ParseError, text_pos: TextSize) { - self.errors.push(SyntaxError::new_at_offset(*error.0, text_pos)); + pub fn error(&mut self, error: String, text_pos: TextSize) { + self.errors.push(SyntaxError::new_at_offset(error, text_pos)); } }