@putout/engine-parser

🐊Putout engine that parses input.

Install

npm i @putout/engine-parser

Supported parsers

• @babel/parse
• acorn
• espree
• esprima
• tenko

Any parser should be installed before use, but you can be shure that @babel/parse always installed.

API

print(ast)

Print code from ast

parse(code)

You can add default options for custom parser you use.

parse.fresh(code)

parse without memoization.

parse.ast(template)

create node using memoization.

parse.ast.fresh(template)

create node without memoization.

Sourcemaps

You have two ways to benefit from source map generation:

• using Recast print;
• using Babel generator;

Generate sourcemaps usign Recast

const source = `const hello = 'world';`;
const ast = parse(source, {
    sourceFileName: 'hello.js',
});
print(ast, {sourceMapName: 'hello.map'});
// returns
`const hello = 'world';
{"version":3,"sources":["hello.js"],"names":[],"mappings":"AAAA...","file":"hello.map","sourcesContent":["const hello = 'world';"]}`;

Generate sourcemaps usign Bebel

To generate sourcemap usig babel generator, you should use babel parser before. This is low level transformation, because Babel doesn't preserve any formatting.

const {generate} = require('@putout/engine-parser');
const babel = require('@putout/engine-parser/babel');

const ast = babel.parse(source, {
    sourceFilename: 'hello.js',
});

generate(ast, {sourceMaps: true}, {
    'hello.js': source,
});
// returns
({code, map});

Example

const {parse} = require('@putout/engin-parser');
const parser = 'acorn';

const code = parse('var t = "hello"', {
    parser,
});

License

MIT