Crate syntax[][src]

Expand description

Syntax Tree library used throughout the rust analyzer.


  • easy and fast incremental re-parsing
  • graceful handling of errors
  • full-fidelity representation (any text can be precisely represented as a syntax tree)

For more information, see the RFC. Current implementation is inspired by the Swift one.

The most interesting modules here are syntax_node (which defines concrete syntax tree) and ast (which defines abstract syntax tree on top of the CST). The actual parser live in a separate parser crate, though the lexer lives in this crate.

See api_walkthrough test in this file for a quick API tour!


pub use crate::ast::AstNode;
pub use crate::ast::AstToken;


Collection of assorted algorithms for syntax trees.

Abstract Syntax Tree, layered on top of untyped SyntaxNodes

This module contains utilities for rendering syntax nodes into a string representing their signature.

Things which exist to solve practial issues, but which shouldn’t exist.

Primitive tree editor, ed for trees.

A set of utils methods to reuse on other abstraction levels


Matches a SyntaxNode against an ast type.


Like SyntaxNodePtr, but remembers the type of node.

Internal node in the immutable tree. It has other nodes and tokens as children.

Parse is the result of the parsing: a syntax tree and a collection of errors.

A SmolStr is a string type that has the following properties:

Represents the result of unsuccessful tokenization, parsing or tree validation.

A range in text, represented as a pair of TextSize.

A measure of text length. Also, equivalently, an index into text.


The kind of syntax node, e.g. IDENT, USE_KW, or STRUCT.

There might be zero, one or two leaves at a given offset.

WalkEvent describes tree walking process.

Type Definitions

A “pointer” to a SyntaxNode, via location in the source code.