@putout/engine-parser [![NPM version][NPMIMGURL]][NPMURL]

[NPMIMGURL]: https://img.shields.io/npm/v/@putout/engine-parser.svg?style=flat&longCache=true
[NPMURL]: https://npmjs.org/package/@putout/engine-parser "npm"

🐊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 sure that @babel/parse always installed.

API

By default @putout/printer used. It formats code according to eslint-plugin-putout rules but without using ESLint.

But you can also use babel with:

`js
const ast = parse(source);
const code = print(ast, {
printer: 'babel',
});
`

When you need to pass options, use:

`js
const code = print(ast, {
printer: ['putout', {
format: {
indent: ' ',
},
}],
});

print(ast, {
printer: ['babel', {
alignSpaces: false, // when you don't want to add spaces on empty lines
}],
});
`

$3

Print code from ast

$3

You can add default options for custom parser you use.

$3

parse without memoization.

$3

create node using memoization.

$3

create node without memoization.

$3

Extract expression node from ExpressionStatement.

#### Generate sourcemaps using Babel

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

`js
import {generate} from '@putout/engine-parser';
import {parse} from '@putout/engine-parser/babel';

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

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

// returns
({
code,
map,
});
`

Example

`js
import {parse} from '@putout/engine-parser';

const parser = 'acorn';

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

License

MIT