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  / __ \/  |/  /__  / /_____ _    / / ___/
 / / / / /|_/ / _ \/ __/ __ `/_  / /\__ \
/ /_/ / /  / /  __/ /_/ /_/ / /_/ /___/ /
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Description

OMetaJS is a JavaScript implementation of OMeta, an object-oriented language for pattern matching.

This is a node.js module for developing and using such pattern matching grammars.

Installation

Installing ometajs

$ [sudo] npm install ometa-js -g

Note: If you are using ometajs programatically you should not install it globally.

$ cd /path/to/your/project
$ npm install ometa-js

Usage

Command line

$ ometajs2js --help

Usage:
  ometajs2js [OPTIONS] [ARGS]


Options:
  -h, --help : Help
  -v, --version : Version
  -i INPUT, --input=INPUT : Input file (default: stdin)
  -o OUTPUT, --output=OUTPUT : Output file (default: stdout)
  --root=ROOT : Path to root module (default: ometajs)

ometajs2js will take input *.ometajs file and produce a CommonJS/AMD/Browser compatible javascript file.

Also you may require('*.ometajs') files directly without compilation. (OmetaJS is patching require.extensions as CoffeeScript does).

Using as CommonJS module

var ometajs = require('ometa-js');

var ast = ometajs.BSJSParser.matchAll('var x = 1', 'topLevel'),
    code = ometajs.BSJSTranslator.matchAll([ast], 'trans');
// Or:
var code = ometajs.compile('var x = 1');

Example

Example grammar

ometa Simple {
  top = [#simple] -> 'ok'
}

More information about OmetaJS syntax.

Use cases

Fast prototyping and building your own parser/language. Processing/traversing complex AST.

Some projects that are using this:

• XJST
• ShmakoWiki
• OmetaHighlighter

More information

To study OmetaJS or ask questions about it's core you can try to reach out original repository author Alessandro Warth or me.

Here is documented code.

Contributors

• Alessandro Warth
• Takashi Yamamiya
• Sergey Berezhnoy
• Nikita Vasilyev
• Fedor Indutny