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1 //! This module defines Concrete Syntax Tree (CST), used by rust-analyzer.
2 //!
3 //! The CST includes comments and whitespace, provides a single node type,
4 //! `SyntaxNode`, and a basic traversal API (parent, children, siblings).
5 //!
6 //! The *real* implementation is in the (language-agnostic) `rowan` crate, this
7 //! module just wraps its API.
8 
9 use rowan::{GreenNodeBuilder, Language};
10 
11 use crate::{Parse, SyntaxError, SyntaxKind, TextSize};
12 
13 pub(crate) use rowan::{GreenNode, GreenToken, NodeOrToken};
14 
15 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
16 pub enum RustLanguage {}
17 impl Language for RustLanguage {
18     type Kind = SyntaxKind;
19 
kind_from_raw(raw: rowan::SyntaxKind) -> SyntaxKind20     fn kind_from_raw(raw: rowan::SyntaxKind) -> SyntaxKind {
21         SyntaxKind::from(raw.0)
22     }
23 
kind_to_raw(kind: SyntaxKind) -> rowan::SyntaxKind24     fn kind_to_raw(kind: SyntaxKind) -> rowan::SyntaxKind {
25         rowan::SyntaxKind(kind.into())
26     }
27 }
28 
29 pub type SyntaxNode = rowan::SyntaxNode<RustLanguage>;
30 pub type SyntaxToken = rowan::SyntaxToken<RustLanguage>;
31 pub type SyntaxElement = rowan::SyntaxElement<RustLanguage>;
32 pub type SyntaxNodeChildren = rowan::SyntaxNodeChildren<RustLanguage>;
33 pub type SyntaxElementChildren = rowan::SyntaxElementChildren<RustLanguage>;
34 pub type PreorderWithTokens = rowan::api::PreorderWithTokens<RustLanguage>;
35 
36 #[derive(Default)]
37 pub struct SyntaxTreeBuilder {
38     errors: Vec<SyntaxError>,
39     inner: GreenNodeBuilder<'static>,
40 }
41 
42 impl SyntaxTreeBuilder {
finish_raw(self) -> (GreenNode, Vec<SyntaxError>)43     pub(crate) fn finish_raw(self) -> (GreenNode, Vec<SyntaxError>) {
44         let green = self.inner.finish();
45         (green, self.errors)
46     }
47 
finish(self) -> Parse<SyntaxNode>48     pub fn finish(self) -> Parse<SyntaxNode> {
49         let (green, errors) = self.finish_raw();
50         // Disable block validation, see https://github.com/rust-lang/rust-analyzer/pull/10357
51         #[allow(clippy::overly_complex_bool_expr)]
52         if cfg!(debug_assertions) && false {
53             let node = SyntaxNode::new_root(green.clone());
54             crate::validation::validate_block_structure(&node);
55         }
56         Parse::new(green, errors)
57     }
58 
token(&mut self, kind: SyntaxKind, text: &str)59     pub fn token(&mut self, kind: SyntaxKind, text: &str) {
60         let kind = RustLanguage::kind_to_raw(kind);
61         self.inner.token(kind, text);
62     }
63 
start_node(&mut self, kind: SyntaxKind)64     pub fn start_node(&mut self, kind: SyntaxKind) {
65         let kind = RustLanguage::kind_to_raw(kind);
66         self.inner.start_node(kind);
67     }
68 
finish_node(&mut self)69     pub fn finish_node(&mut self) {
70         self.inner.finish_node();
71     }
72 
error(&mut self, error: String, text_pos: TextSize)73     pub fn error(&mut self, error: String, text_pos: TextSize) {
74         self.errors.push(SyntaxError::new_at_offset(error, text_pos));
75     }
76 }
77