Crate boa_ast

Boa’s boa_ast crate implements an ECMAScript abstract syntax tree.

Crate Overview

boa_ast contains representations of Parse Nodes as defined by the ECMAScript spec. Some Parse Nodes are not represented by Boa’s AST, because a lot of grammar productions are only used to throw Early Errors, and don’t influence the evaluation of the AST itself.

Boa’s AST is mainly split in three main components: Declarations, Expressions and Statements, with StatementList being the primordial Parse Node that combines all of them to create a proper AST.

About Boa

Boa is an open-source, experimental ECMAScript Engine written in Rust for lexing, parsing and executing ECMAScript/JavaScript. Currently, Boa supports some of the language. More information can be viewed at Boa’s website.

Try out the most recent release with Boa’s live demo playground.

Boa Crates

• boa_ast - Boa’s ECMAScript Abstract Syntax Tree.
• boa_engine - Boa’s implementation of ECMAScript builtin objects and execution.
• boa_gc - Boa’s garbage collector.
• boa_interner - Boa’s string interner.
• boa_parser - Boa’s lexer and parser.
• boa_profiler - Boa’s code profiler.
• boa_icu_provider - Boa’s ICU4X data provider.
• boa_runtime - Boa’s WebAPI features.

Re-exports

• pub use self::declaration::Declaration;
• pub use self::expression::Expression;
• pub use self::keyword::Keyword;
• pub use self::statement::Statement;

Modules

• declaration
  The Declaration Parse Node, as defined by the spec.
• expression
  The Expression Parse Node, as defined by the spec.
• function
  Functions and classes nodes, as defined by the spec.
• keyword
  The Keyword AST node, which represents reserved words of the ECMAScript language.
• module_item_list 🔒
  Module item list AST nodes.
• operations
  Definitions of various Syntax-Directed Operations used in the spec.
• pattern
  A pattern binding or assignment node.
• position 🔒
• property
  Property definition related types, used in object literals and class definitions.
• punctuator 🔒
  The Punctuator enum, which contains all punctuators used in ECMAScript.
• source 🔒
• statement
  The Statement Parse Node, as defined by the spec.
• statement_list 🔒
  Statement list node.
• visitor
  ECMAScript Abstract Syntax Tree visitors.

Macros

• try_break
  Try-like conditional unwrapping of ControlFlow.

Structs

• Module
  A Module source.
• ModuleItemList
  Module item list AST node.
• Position
  A position in the ECMAScript source code.
• Script
  A Script source.
• Span
  A span in the ECMAScript source code.
• StatementList
  List of statements.

Enums

• ModuleItem
  Module item AST node.
• Punctuator
  All of the punctuators used in ECMAScript.
• StatementListItem
  An item inside a StatementList Parse Node, as defined by the spec.

Traits

• ToStringEscaped 🔒
  Utility trait that adds a UTF-16 escaped representation to every [u16].

Functions

• block_to_string 🔒
  Displays the body of a block or statement list.
• join_nodes 🔒
  Utility to join multiple Nodes into a single string.