src/tools/rust-analyzer/crates/syntax/src/syntax_node.rs

   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
  20     fn kind_from_raw(raw: rowan::SyntaxKind) -> SyntaxKind {
  21         SyntaxKind::from(raw.0)
  22     }
  23
  24     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 {
  43     pub(crate) fn finish_raw(self) -> (GreenNode, Vec<SyntaxError>) {
  44         let green = self.inner.finish();
  45         (green, self.errors)
  46     }
  47
  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
  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
  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
  69     pub fn finish_node(&mut self) {
  70         self.inner.finish_node();
  71     }
  72
  73     pub fn error(&mut self, error: String, text_pos: TextSize) {
  74         self.errors.push(SyntaxError::new_at_offset(error, text_pos));
  75     }
  76 }