Oxc Parser for JavaScript and TypeScript

Performance

The following optimization techniques are used:

AST is allocated in a memory arena (bumpalo) for fast AST drop
Short strings are inlined by CompactString
No other heap allocations are done expect the above two
SIMD is used for skipping whitespace and multiline comments
[oxc_ast::Span] offsets uses u32 instead of usize
Scope binding, symbol resolution and complicated syntax errors are not done in the parser, they are deligated to the semantic analyzer

Conformance

The parser parses all of Test262 and most of Babel and TypeScript parser conformance tests.

Test262 Summary:
AST Parsed     : 44000/44000 (100.00%)

Babel Summary:
AST Parsed     : 2065/2071 (99.71%)

TypeScript Summary:
AST Parsed     : 2337/2337 (100.00%)

Usage

The parser has a minimal API with three inputs and one return struct ([ParserReturn]).

let parser_return = Parser::new(&allocator, &source_text, source_type).parse();

Example

https://github.com/Boshen/oxc/blob/main/crates/oxc_parser/examples/parser.rs

Visitor

See [oxc_ast::visit::Visit] and [oxc_ast::visit_mut::VisitMut]

Visiting without a visitor

For ad-hoc tasks, the semantic analyzer can be used to get a parent pointing tree with untyped nodes, the nodes can be iterated through a sequential loop.

for node in semantic.nodes().iter() {
match node.get().kind() {
// check node
}
}