321 lines
No EOL
8.7 KiB
Markdown
321 lines
No EOL
8.7 KiB
Markdown
# snapdragon [](https://www.npmjs.com/package/snapdragon) [](https://npmjs.org/package/snapdragon) [](https://travis-ci.org/jonschlinkert/snapdragon)
|
|
|
|
> Fast, pluggable and easy-to-use parser-renderer factory.
|
|
|
|
## Install
|
|
|
|
Install with [npm](https://www.npmjs.com/):
|
|
|
|
```sh
|
|
$ npm install --save snapdragon
|
|
```
|
|
|
|
Created by [jonschlinkert](https://github.com/jonschlinkert) and [doowb](https://github.com/doowb).
|
|
|
|
**Features**
|
|
|
|
* Bootstrap your own parser, get sourcemap support for free
|
|
* All parsing and compiling is handled by simple, reusable middleware functions
|
|
* Inspired by the parsers in [pug](http://jade-lang.com) and [css](https://github.com/reworkcss/css).
|
|
|
|
## History
|
|
|
|
### v0.5.0
|
|
|
|
**Breaking changes**
|
|
|
|
Substantial breaking changes were made in v0.5.0! Most of these changes are part of a larger refactor that will be finished in 0.6.0, including the introduction of a `Lexer` class.
|
|
|
|
* Renderer was renamed to `Compiler`
|
|
* the `.render` method was renamed to `.compile`
|
|
* Many other smaller changes. A more detailed overview will be provided in 0.6.0. If you don't have to time review code, I recommend you wait for the 0.6.0 release.
|
|
|
|
## Usage examples
|
|
|
|
```js
|
|
var Snapdragon = require('snapdragon');
|
|
var snapdragon = new Snapdragon();
|
|
```
|
|
|
|
**Parse**
|
|
|
|
```js
|
|
var ast = snapdragon.parser('some string', options)
|
|
// parser middleware that can be called by other middleware
|
|
.set('foo', function () {})
|
|
// parser middleware, runs immediately in the order defined
|
|
.use(bar())
|
|
.use(baz())
|
|
```
|
|
|
|
**Render**
|
|
|
|
```js
|
|
// pass the `ast` from the parse method
|
|
var res = snapdragon.compiler(ast)
|
|
// compiler middleware, called when the name of the middleware
|
|
// matches the `node.type` (defined in a parser middleware)
|
|
.set('bar', function () {})
|
|
.set('baz', function () {})
|
|
.compile()
|
|
```
|
|
|
|
See the [examples](./examples/).
|
|
|
|
## Getting started
|
|
|
|
**Parsers**
|
|
|
|
Parsers are middleware functions used for parsing a string into an ast node.
|
|
|
|
```js
|
|
var ast = snapdragon.parser(str, options)
|
|
.use(function() {
|
|
var pos = this.position();
|
|
var m = this.match(/^\./);
|
|
if (!m) return;
|
|
return pos({
|
|
// `type` specifies the compiler to use
|
|
type: 'dot',
|
|
val: m[0]
|
|
});
|
|
})
|
|
```
|
|
|
|
**AST node**
|
|
|
|
When the parser finds a match, `pos()` is called, pushing a token for that node onto the ast that looks something like:
|
|
|
|
```js
|
|
{ type: 'dot',
|
|
val: '.',
|
|
position:
|
|
{ start: { lineno: 1, column: 1 },
|
|
end: { lineno: 1, column: 2 } }}
|
|
```
|
|
|
|
**Renderers**
|
|
|
|
Renderers are _named_ middleware functions that visit over an array of ast nodes to compile a string.
|
|
|
|
```js
|
|
var res = snapdragon.compiler(ast)
|
|
.set('dot', function (node) {
|
|
console.log(node.val)
|
|
//=> '.'
|
|
return this.emit(node.val);
|
|
})
|
|
```
|
|
|
|
**Source maps**
|
|
|
|
If you want source map support, make sure to emit the position as well.
|
|
|
|
```js
|
|
var res = snapdragon.compiler(ast)
|
|
.set('dot', function (node) {
|
|
return this.emit(node.val, node.position);
|
|
})
|
|
```
|
|
|
|
## Docs
|
|
|
|
### Parser middleware
|
|
|
|
A parser middleware is a function that returns an abject called a `token`. This token is pushed onto the AST as a node.
|
|
|
|
**Example token**
|
|
|
|
```js
|
|
{ type: 'dot',
|
|
val: '.',
|
|
position:
|
|
{ start: { lineno: 1, column: 1 },
|
|
end: { lineno: 1, column: 2 } }}
|
|
```
|
|
|
|
**Example parser middleware**
|
|
|
|
Match a single `.` in a string:
|
|
|
|
1. Get the starting position by calling `this.position()`
|
|
2. pass a regex for matching a single dot to the `.match` method
|
|
3. if **no match** is found, return `undefined`
|
|
4. if a **match** is found, `pos()` is called, which returns a token with:
|
|
- `type`: the name of the [compiler] to use
|
|
- `val`: The actual value captured by the regex. In this case, a `.`. Note that you can capture and return whatever will be needed by the corresponding [compiler].
|
|
- The ending position: automatically calculated by adding the length of the first capture group to the starting position.
|
|
|
|
## Renderer middleware
|
|
|
|
Renderers are run when the name of the compiler middleware matches the `type` defined on an ast `node` (which is defined in a parser).
|
|
|
|
**Example**
|
|
|
|
Exercise: Parse a dot, then compile it as an escaped dot.
|
|
|
|
```js
|
|
var ast = snapdragon.parser('.')
|
|
.use(function () {
|
|
var pos = this.position();
|
|
var m = this.match(/^\./);
|
|
if (!m) return;
|
|
return pos({
|
|
// define the `type` of compiler to use
|
|
type: 'dot',
|
|
val: m[0]
|
|
})
|
|
})
|
|
|
|
var result = snapdragon.compiler(ast)
|
|
.set('dot', function (node) {
|
|
return this.emit('\\' + node.val);
|
|
})
|
|
.compile()
|
|
|
|
console.log(result.output);
|
|
//=> '\.'
|
|
```
|
|
|
|
## API
|
|
|
|
### [Parser](lib/parser.js#L19)
|
|
|
|
Create a new `Parser` with the given `input` and `options`.
|
|
|
|
**Params**
|
|
|
|
* `input` **{String}**
|
|
* `options` **{Object}**
|
|
|
|
### [.define](lib/parser.js#L103)
|
|
|
|
Define a non-enumberable property on the `Parser` instance.
|
|
|
|
**Example**
|
|
|
|
```js
|
|
parser.define('foo', 'bar');
|
|
```
|
|
|
|
**Params**
|
|
|
|
* `key` **{String}**: propery name
|
|
* `val` **{any}**: property value
|
|
* `returns` **{Object}**: Returns the Parser instance for chaining.
|
|
|
|
Set parser `name` with the given `fn`
|
|
|
|
**Params**
|
|
|
|
* `name` **{String}**
|
|
* `fn` **{Function}**
|
|
|
|
Get parser `name`
|
|
|
|
**Params**
|
|
|
|
* `name` **{String}**
|
|
|
|
Push a `token` onto the `type` stack.
|
|
|
|
**Params**
|
|
|
|
* `type` **{String}**
|
|
* `returns` **{Object}** `token`
|
|
|
|
Pop a token off of the `type` stack
|
|
|
|
**Params**
|
|
|
|
* `type` **{String}**
|
|
* `returns` **{Object}**: Returns a token
|
|
|
|
Return true if inside a `stack` node. Types are `braces`, `parens` or `brackets`.
|
|
|
|
**Params**
|
|
|
|
* `type` **{String}**
|
|
* `returns` **{Boolean}**
|
|
|
|
**Example**
|
|
|
|
```js
|
|
parser.isType(node, 'brace');
|
|
```
|
|
|
|
**Params**
|
|
|
|
* `node` **{Object}**
|
|
* `type` **{String}**
|
|
* `returns` **{Boolean}**
|
|
|
|
### [.define](lib/compiler.js#L71)
|
|
|
|
Define a non-enumberable property on the `Compiler` instance.
|
|
|
|
**Example**
|
|
|
|
```js
|
|
compiler.define('foo', 'bar');
|
|
```
|
|
|
|
**Params**
|
|
|
|
* `key` **{String}**: propery name
|
|
* `val` **{any}**: property value
|
|
* `returns` **{Object}**: Returns the Compiler instance for chaining.
|
|
|
|
## About
|
|
|
|
### Related projects
|
|
|
|
* [braces](https://www.npmjs.com/package/braces): Fastest brace expansion for node.js, with the most complete support for the Bash 4.3 braces… [more](https://github.com/jonschlinkert/braces) | [homepage](https://github.com/jonschlinkert/braces "Fastest brace expansion for node.js, with the most complete support for the Bash 4.3 braces specification.")
|
|
* [expand-brackets](https://www.npmjs.com/package/expand-brackets): Expand POSIX bracket expressions (character classes) in glob patterns. | [homepage](https://github.com/jonschlinkert/expand-brackets "Expand POSIX bracket expressions (character classes) in glob patterns.")
|
|
* [extglob](https://www.npmjs.com/package/extglob): Convert extended globs to regex-compatible strings. Add (almost) the expressive power of regular expressions to… [more](https://github.com/jonschlinkert/extglob) | [homepage](https://github.com/jonschlinkert/extglob "Convert extended globs to regex-compatible strings. Add (almost) the expressive power of regular expressions to glob patterns.")
|
|
* [micromatch](https://www.npmjs.com/package/micromatch): Glob matching for javascript/node.js. A drop-in replacement and faster alternative to minimatch and multimatch. | [homepage](https://github.com/jonschlinkert/micromatch "Glob matching for javascript/node.js. A drop-in replacement and faster alternative to minimatch and multimatch.")
|
|
|
|
### Contributing
|
|
|
|
Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new).
|
|
|
|
### Contributors
|
|
|
|
| **Commits** | **Contributor**<br/> |
|
|
| --- | --- |
|
|
| 106 | [jonschlinkert](https://github.com/jonschlinkert) |
|
|
| 2 | [doowb](https://github.com/doowb) |
|
|
|
|
### Building docs
|
|
|
|
_(This document was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme) (a [verb](https://github.com/verbose/verb) generator), please don't edit the readme directly. Any changes to the readme must be made in [.verb.md](.verb.md).)_
|
|
|
|
To generate the readme and API documentation with [verb](https://github.com/verbose/verb):
|
|
|
|
```sh
|
|
$ npm install -g verb verb-generate-readme && verb
|
|
```
|
|
|
|
### Running tests
|
|
|
|
Install dev dependencies:
|
|
|
|
```sh
|
|
$ npm install -d && npm test
|
|
```
|
|
|
|
### Author
|
|
|
|
**Jon Schlinkert**
|
|
|
|
* [github/jonschlinkert](https://github.com/jonschlinkert)
|
|
* [twitter/jonschlinkert](http://twitter.com/jonschlinkert)
|
|
|
|
### License
|
|
|
|
Copyright © 2016, [Jon Schlinkert](https://github.com/jonschlinkert).
|
|
Released under the [MIT license](https://github.com/jonschlinkert/snapdragon/blob/master/LICENSE).
|
|
|
|
***
|
|
|
|
_This file was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme), v0.1.31, on October 10, 2016._ |