bloom-layout
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layout components used in bloom packages
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//travis-ci.org/json5/json5.svg)](https://travis-ci.org/json5/json5)
JSON is an excellent data format, but we think it can be better.
**JSON5 is a proposed extension to JSON** that aims to make it easier for
*humans to write and maintain* by hand. It does this by adding some minimal
syntax features directly from ECMAScript 5.
JSON5 remains a **strict subset of JavaScript**, adds **no new data types**,
and **works with all existing JSON content**.
JSON5 is *not* an official successor to JSON, and JSON5 content may *not*
work with existing JSON parsers. For this reason, JSON5 files use a new .json5
extension. *(TODO: new MIME type needed too.)*
The code here is a **reference JavaScript implementation** for both Node.js
and all browsers. It’s based directly off of Douglas Crockford’s own [JSON
implementation][json_parse.js], and it’s both robust and secure.
JSON isn’t the friendliest to *write*. Keys need to be quoted, objects and
arrays can’t have trailing commas, and comments aren’t allowed — even though
none of these are the case with regular JavaScript today.
That was fine when JSON’s goal was to be a great data format, but JSON’s usage
has expanded beyond *machines*. JSON is now used for writing [configs][ex1],
[ ][ex2], even [tests][ex3] — all by *humans*.
[ ]: http://plovr.com/docs.html
[ ]: https://www.npmjs.org/doc/files/package.json.html
[ ]: http://code.google.com/p/fuzztester/wiki/JSONFileFormat
There are other formats that are human-friendlier, like YAML, but changing
from JSON to a completely different format is undesirable in many cases.
JSON5’s aim is to remain close to JSON and JavaScript.
The following is the exact list of additions to JSON’s syntax introduced by
JSON5. **All of these are optional**, and **all of these come from ES5**.
- Object keys can be unquoted if they’re valid [identifiers][mdn_variables].
Yes, even reserved keywords (like `default`) are valid unquoted keys in ES5
[[§11.1.5](http://es5.github.com/#x11.1.5), [§7.6](http://es5.github.com/#x7.6)].
([More info](https://mathiasbynens.be/notes/javascript-identifiers))
*(TODO: Unicode characters and escape sequences aren’t yet supported in this
implementation.)*
- Object keys can also be single-quoted.
- Objects can have trailing commas.
[mdn_variables]: https://developer.mozilla.org/en/Core_JavaScript_1.5_Guide/Core_Language_Features#Variables
### Arrays
- Arrays can have trailing commas.
### Strings
- Strings can be single-quoted.
- Strings can be split across multiple lines; just prefix each newline with a
backslash. [ES5 [§7.8.4](http://es5.github.com/#x7.8.4)]
- Numbers can be hexadecimal (base 16).
- Numbers can begin or end with a (leading or trailing) decimal point.
- Numbers can include `Infinity`, `-Infinity`, `NaN`, and `-NaN`.
- Numbers can begin with an explicit plus sign.
### Comments
- Both inline (single-line) and block (multi-line) comments are allowed.
## Example
The following is a contrived example, but it illustrates most of the features:
```js
{
foo: 'bar',
while: true,
this: 'is a \
multi-line string',
// this is an inline comment
here: 'is another', // inline comment
/* this is a block comment
that continues on another line */
hex: 0xDEADbeef,
half: .5,
delta: +10,
to: Infinity, // and beyond!
finally: 'a trailing comma',
oh: [
"we shouldn't forget",
'arrays can have',
'trailing commas too',
],
}
```
This implementation’s own [package.json5](package.json5) is more realistic:
```js
// This file is written in JSON5 syntax, naturally, but npm needs a regular
// JSON file, so compile via `npm run build`. Be sure to keep both in sync!
{
name: 'json5',
version: '0.5.0',
description: 'JSON for the ES5 era.',
keywords: ['json', 'es5'],
author: 'Aseem Kishore <aseem.kishore@gmail.com>',
contributors: [
// TODO: Should we remove this section in favor of GitHub's list?
// https://github.com/aseemk/json5/contributors
'Max Nanasy <max.nanasy@gmail.com>',
'Andrew Eisenberg <andrew@eisenberg.as>',
'Jordan Tucker <jordanbtucker@gmail.com>',
],
main: 'lib/json5.js',
bin: 'lib/cli.js',
files: ["lib/"],
dependencies: {},
devDependencies: {
gulp: "^3.9.1",
'gulp-jshint': "^2.0.0",
jshint: "^2.9.1",
'jshint-stylish': "^2.1.0",
mocha: "^2.4.5"
},
scripts: {
build: 'node ./lib/cli.js -c package.json5',
test: 'mocha --ui exports --reporter spec',
// TODO: Would it be better to define these in a mocha.opts file?
},
homepage: 'http://json5.org/',
license: 'MIT',
repository: {
type: 'git',
url: 'https://github.com/aseemk/json5.git',
},
}
```
Join the [Google Group](http://groups.google.com/group/json5) if you’re
interested in JSON5 news, updates, and general discussion.
Don’t worry, it’s very low-traffic.
The [GitHub wiki](https://github.com/aseemk/json5/wiki) is a good place to track
JSON5 support and usage. Contribute freely there!
[ ](https://github.com/aseemk/json5/issues) is the place to
formally propose feature requests and report bugs. Questions and general
feedback are better directed at the Google Group.
This JavaScript implementation of JSON5 simply provides a `JSON5` object just
like the native ES5 `JSON` object.
To use from Node:
```sh
npm install json5
```
```js
var JSON5 = require('json5');
```
To use in the browser (adds the `JSON5` object to the global namespace):
```html
<script src="json5.js"></script>
```
Then in both cases, you can simply replace native `JSON` calls with `JSON5`:
```js
var obj = JSON5.parse('{unquoted:"key",trailing:"comma",}');
var str = JSON5.stringify(obj);
```
`JSON5.parse` supports all of the JSON5 features listed above (*TODO: except
Unicode*), as well as the native [`reviver` argument][json-parse].
[json-parse]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse
`JSON5.stringify` mainly avoids quoting keys where possible, but we hope to
keep expanding it in the future (e.g. to also output trailing commas).
It supports the native [`replacer` and `space` arguments][json-stringify],
as well. *(TODO: Any implemented `toJSON` methods aren’t used today.)*
[json-stringify]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify
### Extras
If you’re running this on Node, you can also register a JSON5 `require()` hook
to let you `require()` `.json5` files just like you can `.json` files:
```js
require('json5/lib/require');
require('./path/to/foo'); // tries foo.json5 after foo.js, foo.json, etc.
require('./path/to/bar.json5');
```
This module also provides a `json5` executable (requires Node) for converting
JSON5 files to JSON:
```sh
json5 -c path/to/foo.json5
```
```sh
git clone git://github.com/aseemk/json5.git
cd json5
npm install
npm test
```
As the `package.json5` file states, be sure to run `npm run build` on changes
to `package.json5`, since npm requires `package.json`.
Feel free to [file issues](https://github.com/aseemk/json5/issues) and submit
[ ](https://github.com/aseemk/json5/pulls) — contributions are
welcome. If you do submit a pull request, please be sure to add or update the
tests, and ensure that `npm test` continues to pass.
MIT. See [LICENSE.md](./LICENSE.md) for details.
[ ](http://bolinfest.com/) independently arrived at and published
some of these same ideas with awesome explanations and detail.
Recommended reading:
[ ](http://bolinfest.com/essays/json.html)
[ ](http://www.crockford.com/) of course designed and built
JSON, but his state machine diagrams on the [JSON website](http://json.org/),
as cheesy as it may sound, gave me motivation and confidence that building a
new parser to implement these ideas this was within my reach!
This code is also modeled directly off of Doug’s open-source [json_parse.js][]
parser. I’m super grateful for that clean and well-documented code.
[ ]: https://github.com/douglascrockford/JSON-js/blob/master/json_parse.js
[ ](https://github.com/MaxNanasy) has been an early and prolific
supporter, contributing multiple patches and ideas. Thanks Max!
[ ](https://github.com/aeisenberg) has contributed the
`stringify` method.
[ ](https://github.com/jordanbtucker) has aligned JSON5 more closely
with ES5 and is actively maintaining this project.
[![Build Status](https: