Crate boa_ast

source ·
Expand description

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




  • Try-like conditional unwrapping of ControlFlow.





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