# YAML <a href="https://www.npmjs.com/package/yaml"><img align="right" src="https://badge.fury.io/js/yaml.svg" title="npm package" /></a><a href="https://travis-ci.org/eemeli/yaml"><img align="right" src="https://travis-ci.org/eemeli/yaml.svg?branch=master" title="Build status" /></a>

`yaml` is a JavaScript parser and stringifier for [YAML](http://yaml.org/), a human friendly data serialization standard. It supports both parsing and stringifying data using all versions of YAML, along with all common data schemas. As a particularly distinguishing feature, `yaml` fully supports reading and writing comments and blank lines in YAML documents.

The library is released under the ISC open source license, and the code is [available on GitHub](https://github.com/eemeli/yaml/). It has no external dependencies, and is usable in both browser and node environments.

For more information, see the project's documentation site: [**eemeli.org/yaml**](https://eemeli.org/yaml/)

> To install:

```sh
npm install yaml
# or
yarn add yaml
```

Note: `yaml` 0.x and 1.x are rather different implementations. For the earlier `yaml`, see [tj/js-yaml](https://github.com/tj/js-yaml).

## API Overview

The API provided by `yaml` has three layers, depending on how deep you need to go: [Pure JavaScript](https://eemeli.org/yaml/#pure-javascript), [YAML Documents](https://eemeli.org/yaml/#yaml-documents), and the [CST Parser](https://eemeli.org/yaml/#cst-parser). The first has the simplest API and "just works", the second gets you all the bells and whistles supported by the library along with a decent [AST](https://eemeli.org/yaml/#content-nodes), and the third is the closest to YAML source, making it fast, raw, and crude.

```js
import YAML from 'yaml'
// or
const YAML = require('yaml')
```

### Pure JavaScript

* [`YAML.parse(str, options): value`](https://eemeli.org/yaml/#yaml-parse)
* [`YAML.stringify(value, options): string`](https://eemeli.org/yaml/#yaml-stringify)

### YAML Documents

* [`YAML.createNode(value, wrapScalars, tag): Node`](https://eemeli.org/yaml/#creating-nodes)
* [`YAML.defaultOptions`](https://eemeli.org/yaml/#options)
* [`YAML.Document`](https://eemeli.org/yaml/#yaml-documents)
  * [`constructor(options)`](https://eemeli.org/yaml/#creating-documents)
  * [`defaults`](https://eemeli.org/yaml/#options)
  * [`#anchors`](https://eemeli.org/yaml/#working-with-anchors)
  * [`#contents`](https://eemeli.org/yaml/#content-nodes)
  * [`#errors`](https://eemeli.org/yaml/#errors)
* [`YAML.parseAllDocuments(str, options): YAML.Document[]`](https://eemeli.org/yaml/#parsing-documents)
* [`YAML.parseDocument(str, options): YAML.Document`](https://eemeli.org/yaml/#parsing-documents)

```js
import Map from 'yaml/map'
import Pair from 'yaml/pair'
import Seq from 'yaml/seq'
```

* [`new Map()`](https://eemeli.org/yaml/#creating-nodes)
* [`new Pair(key, value)`](https://eemeli.org/yaml/#creating-nodes)
* [`new Seq()`](https://eemeli.org/yaml/#creating-nodes)

### CST Parser

```js
import parseCST from 'yaml/parse-cst'
```

* [`parseCST(str): CSTDocument[]`](https://eemeli.org/yaml/#parsecst)
* [`YAML.parseCST(str): CSTDocument[]`](https://eemeli.org/yaml/#parsecst)

## YAML.parse

```yaml
# file.yml
YAML:
  - A human-readable data serialization language
  - https://en.wikipedia.org/wiki/YAML
yaml:
  - A complete JavaScript implementation
  - https://www.npmjs.com/package/yaml
```

```js
import fs from 'fs'
import YAML from 'yaml'

YAML.parse('3.14159')
// 3.14159

YAML.parse('[ true, false, maybe, null ]\n')
// [ true, false, 'maybe', null ]

const file = fs.readFileSync('./file.yml', 'utf8')
YAML.parse(file)
// { YAML:
//   [ 'A human-readable data serialization language',
//     'https://en.wikipedia.org/wiki/YAML' ],
//   yaml:
//   [ 'A complete JavaScript implementation',
//     'https://www.npmjs.com/package/yaml' ] }
```

## YAML.stringify

```js
import YAML from 'yaml'

YAML.stringify(3.14159)
// '3.14159\n'

YAML.stringify([true, false, 'maybe', null])
// `- true
// - false
// - maybe
// - null
// `

YAML.stringify({ number: 3, plain: 'string', block: 'two\nlines\n' })
// `number: 3
// plain: string
// block: >
//   two
//
//   lines
// `
```
