oxc/crates/oxc_module_lexer/examples/module_lexer.rs
Boshen 32303b20fb
New tool: oxc_module_lexer (#2650)
# Oxc Module Lexer

This is not a lexer. The name "lexer" is used for easier recognition.

## [es-module-lexer](https://github.com/guybedford/es-module-lexer)

Outputs the list of exports and locations of import specifiers,
including dynamic import and import meta handling.

Does not have any
[limitations](https://github.com/guybedford/es-module-lexer?tab=readme-ov-file#limitations)
mentioned in `es-module-lexer`.

I'll also work on the following cases to make this feature complete.

- [ ] get imported variables
https://github.com/guybedford/es-module-lexer/issues/163
- [ ] track star exports as imports as well
https://github.com/guybedford/es-module-lexer/issues/76
- [ ] TypeScript specific syntax
- [ ] TypeScript `type` import / export keyword

## [cjs-module-lexer](https://github.com/nodejs/cjs-module-lexer)

- [ ] TODO

## Benchmark

This is 2 times slower than `es-module-lexer`, but will be significantly
faster when TypeScript is processed.

The difference is around 10ms vs 20ms on a large file (700k).
2024-03-09 23:23:55 +08:00

46 lines
1.2 KiB
Rust

use std::{env, path::Path};
use oxc_allocator::Allocator;
use oxc_module_lexer::ModuleLexer;
use oxc_parser::Parser;
use oxc_span::SourceType;
// Instruction:
// * create a `test.js`
// * `just example module_lexer
fn main() -> Result<(), String> {
let name = env::args().nth(1).unwrap_or_else(|| "test.js".to_string());
let path = Path::new(&name);
let source_text = std::fs::read_to_string(path).map_err(|_| format!("Missing '{name}'"))?;
let allocator = Allocator::default();
let source_type = SourceType::from_path(path).unwrap();
let ret = Parser::new(&allocator, &source_text, source_type).parse();
println!("source:");
println!("{source_text}");
for error in ret.errors {
let error = error.with_source_code(source_text.clone());
println!("{error:?}");
println!("Parsed with Errors.");
}
let ModuleLexer { imports, exports, facade, has_module_syntax } =
ModuleLexer::new().build(&ret.program);
println!("\nimports:");
for import in imports {
println!("{import:?}");
}
println!("\nexports:");
for export in exports {
println!("{export:?}");
}
println!("\nfacade: {facade}");
println!("has_module_syntax {has_module_syntax}");
Ok(())
}