forked from lix-project/lix-website
62 lines
1.2 KiB
Markdown
62 lines
1.2 KiB
Markdown
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# is-reference
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Utility for determining whether an AST node is a reference.
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`foo` is a reference in these cases:
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```js
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console.log( foo );
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var foo;
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function foo () {}
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function bar ( foo ) {}
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export { foo as x };
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```
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`foo` is *not* a reference in these cases:
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```js
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var obj = { foo: 1 };
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console.log( obj.foo );
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export { x as foo };
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```
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In all cases, `foo` is an `Identifier` node, but the two kinds must be treated differently for the purposes of scope analysis etc. (The examples are non-exhaustive.)
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## Installation
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```bash
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npm install is-reference
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```
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## Usage
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Example using [Acorn](https://github.com/ternjs/acorn) and [estree-walker](https://github.com/Rich-Harris/estree-walker):
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```js
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const { parse } = require( 'acorn' );
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const { walk } = require( 'estree-walker' );
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const isReference = require( 'is-reference' );
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const identifiers = [];
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const references = [];
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const ast = parse( `var a = b.c;` );
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walk( ast, {
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enter ( node, parent ) {
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if ( node.type === 'Identifier' ) identifiers.push( node );
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if ( isReference( node, parent ) ) references.push( node );
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}
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});
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identifiers.forEach( node => console.log( node.name ) ); // a, b, c
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references.forEach( node => console.log( node.name ) ); // a, b
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```
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## License
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MIT
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