rust/crates/syntax/src/syntax_node.rs
2020-08-12 18:30:53 +02:00

78 lines
2.3 KiB
Rust

//! This module defines Concrete Syntax Tree (CST), used by rust-analyzer.
//!
//! The CST includes comments and whitespace, provides a single node type,
//! `SyntaxNode`, and a basic traversal API (parent, children, siblings).
//!
//! The *real* implementation is in the (language-agnostic) `rowan` crate, this
//! module just wraps its API.
use rowan::{GreenNodeBuilder, Language};
use crate::{Parse, SmolStr, SyntaxError, SyntaxKind, TextSize};
pub use rowan::GreenNode;
pub(crate) use rowan::GreenToken;
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub enum RustLanguage {}
impl Language for RustLanguage {
type Kind = SyntaxKind;
fn kind_from_raw(raw: rowan::SyntaxKind) -> SyntaxKind {
SyntaxKind::from(raw.0)
}
fn kind_to_raw(kind: SyntaxKind) -> rowan::SyntaxKind {
rowan::SyntaxKind(kind.into())
}
}
pub type SyntaxNode = rowan::SyntaxNode<RustLanguage>;
pub type SyntaxToken = rowan::SyntaxToken<RustLanguage>;
pub type SyntaxElement = rowan::SyntaxElement<RustLanguage>;
pub type SyntaxNodeChildren = rowan::SyntaxNodeChildren<RustLanguage>;
pub type SyntaxElementChildren = rowan::SyntaxElementChildren<RustLanguage>;
pub use rowan::{Direction, NodeOrToken};
#[derive(Default)]
pub struct SyntaxTreeBuilder {
errors: Vec<SyntaxError>,
inner: GreenNodeBuilder<'static>,
}
impl SyntaxTreeBuilder {
pub(crate) fn finish_raw(self) -> (GreenNode, Vec<SyntaxError>) {
let green = self.inner.finish();
(green, self.errors)
}
pub fn finish(self) -> Parse<SyntaxNode> {
let (green, errors) = self.finish_raw();
if cfg!(debug_assertions) {
let node = SyntaxNode::new_root(green.clone());
crate::validation::validate_block_structure(&node);
}
Parse::new(green, errors)
}
pub fn token(&mut self, kind: SyntaxKind, text: SmolStr) {
let kind = RustLanguage::kind_to_raw(kind);
self.inner.token(kind, text)
}
pub fn start_node(&mut self, kind: SyntaxKind) {
let kind = RustLanguage::kind_to_raw(kind);
self.inner.start_node(kind)
}
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))
}
}