Crate syntax

Syntax Tree library used throughout the rust-analyzer.

Properties:

• 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!

Re-exports

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

Modules

• algo
  Collection of assorted algorithms for syntax trees.
• ast
  Abstract Syntax Tree, layered on top of untyped SyntaxNodes
• hacks
  Things which exist to solve practical issues, but which shouldn’t exist.
• syntax_editor
  Syntax Tree editor
• ted
  Primitive tree editor, ed for trees.
• unescape
  Utilities for validating string and char literals and turning them into values they represent.
• utils
  A set of utils methods to reuse on other abstraction levels

Macros

• T
• format_smolstr
  Formats arguments to a SmolStr, potentially without allocating.
• match_ast
  Matches a SyntaxNode against an ast type.

Structs

• AstPtr
  Like SyntaxNodePtr, but remembers the type of node.
• GreenNode
  Internal node in the immutable tree. It has other nodes and tokens as children.
• Parse
  Parse is the result of the parsing: a syntax tree and a collection of errors.
• Preorder
• SmolStr
  A SmolStr is a string type that has the following properties:
• SmolStrBuilder
  A builder that can be used to efficiently build a SmolStr.
• SyntaxError
  Represents the result of unsuccessful tokenization, parsing or tree validation.
• SyntaxText
• SyntaxTreeBuilder
• TextRange
  A range in text, represented as a pair of TextSize.
• TextSize
  A measure of text length. Also, equivalently, an index into text.
• TokenText

Enums

• Direction
• Edition
• NodeOrToken
• RustLanguage
• SyntaxKind
  The kind of syntax node, e.g. IDENT, USE_KW, or STRUCT.
• TokenAtOffset
  There might be zero, one or two leaves at a given offset.
• WalkEvent
  WalkEvent describes tree walking process.

Traits

• ToSmolStr
  Convert value to SmolStr using fmt::Display, potentially without allocating.

Type Aliases

• PreorderWithTokens
• SyntaxElement
• SyntaxElementChildren
• SyntaxNode
• SyntaxNodeChildren
• SyntaxNodePtr
  A “pointer” to a SyntaxNode, via location in the source code.
• SyntaxToken