**6to5** turns ES6 code into vanilla ES5, so you can use ES6 features **today.**
- **Fast** - [10x faster than Traceur](#performance).
- **Extensive** - with Browserify support, Node API, Connect Middleware and a CLI.
- **Lossless** - **source map support** so you can debug your compiled code with ease.
- **Compact** - maps directly to the equivalent ES5 with **no runtime**.
- **Concise** - does not pollute scope with unneccesary variables.
## Installation
$ npm install -g 6to5
## [Features](FEATURES.md)
- [Array comprehension](FEATURES.md#array-comprehension)
- [Arrow functions](FEATURES.md#arrow-functions)
- [Block binding](FEATURES.md#block-binding)
- [Classes](FEATURES.md#classes)
- [Computed property names](FEATURES.md#computed-property-names)
- [Constants](FEATURES.md#constants)
- [Default parameters](FEATURES.md#default-parameters)
- [Destructuring](FEATURES.md#destructuring)
- [For-of](FEATURES.md#for-of)
- [Modules](FEATURES.md#modules)
- [Numeric Literals](FEATURES.md#numeric-literals)
- [Spread](FEATURES.md#spread)
- [Property method assignment](FEATURES.md#property-method-assignment)
- [Property name shorthand](FEATURES.md#property-name-shorthand)
- [Rest parameters](FEATURES.md#rest-parameters)
- [Template literals](FEATURES.md#template-literals)
To be implemented:
- [Generators](FEATURES.md#generators)
## Usage
### CLI
Compile the file `script.js` and output it to `script-compiled.js`.
$ 6to5 script.js -o script-compiled.js
Compile the entire `src` directory and output it to the `lib` directory.
$ 6to5 src -d lib
Compile the file `script.js` and output it to stdout.
$ 6to5 script.js
### Browserify
$ browserify script.js -t 6to5/browserify --outfile bundle.js
### Node
```javascript
var to5 = require("6to5");
to5.transform("code();");
to5.transformFileSync("script.js");
to5.transformFile("script.js", function (err, data) {
});
```
##### Options
```javascript
to5.transform("code();", {
// List of transformers to EXCLUDE
// This is a camelised version of the name found in `features`
// eg. "Arrow functions" is "arrowFunctions"
blacklist: [],
// List of transformers to ONLY use.
// See `blacklist` for naming scheme.
whitelist: [],
// Append source map and comment to bottom of returned output.
sourceMap: false,
// Filename for use in errors etc.
filename: "unknown",
// Format options
// See https://github.com/Constellation/escodegen/wiki/API for options.
format: {}
});
```
#### Require hook
All subsequent files required by node will be transformed into ES5 compatible
code.
```javascript
require("6to5/register");
```
#### Connect Middleware
```javascript
var to5 = require("6to5");
app.use(to5.middleware({
options: {
// options to use when transforming files
},
src: "assets",
dest: "cache"
}));
app.use(connect.static("cache"));
```
#### Browserify
```javascript
var to5 = require("6to5");
browserify()
.transform(to5.browserify)
.require("script.js", { entry: true })
.bundle({ debug: true })
.pipe(fs.createWriteStream("bundle.js"));
```
## Caveats
### For-of
### Classes
Cannot subclass built-ins such as `Date`, `Array`, `DOM` etc.
### Generator comprehension
Not supported.
## Comparison to Traceur
### Performance