Jison
An API for creating parsers in JavaScript
Jison generates bottom-up parsers in JavaScript. Its API is similar to Bison's, hence the name. It supports many of Bison's major features, plus some of its own. If you are new to parser generators such as Bison, and Context-free Grammars in general, a good introduction is found in the Bison manual. If you already know Bison, Jison should be easy to pickup.
Briefly, Jison takes a JSON encoded grammar or Bison style grammar and outputs a JavaScript file capable of parsing the language described by that grammar. You can then use the generated script to parse inputs and accept, reject, or perform actions based on the input.
Installation
Jison can be installed for Node using npm
Using npm:
npm install jison -g
Usage from the command line
Clone the github repository for examples:
git clone git://github.com/zaach/jison.git
cd jison/examples
Now you're ready to generate some parsers:
jison calculator.jison
This will generate calculator.js in your current working directory. This file can be used to parse an input file, like so:
echo "2^32 / 1024" > testcalc
node calculator.js testcalc
This will print out 4194304.
Full cli option list:
Usage: jison [file] [lexfile] [options]
file file containing a grammar
lexfile file containing a lexical grammar
Options:
-j, --json force jison to expect a grammar in JSON format
-o FILE, --outfile FILE Filename and base module name of the generated parser
-t, --debug Debug mode
-m TYPE, --module-type TYPE The type of module to generate (commonjs, amd, js)
-p TYPE, --parser-type TYPE The type of algorithm to use for the parser (lr0, slr, lalr, lr)
-V, --version print version and exit
Usage from a CommonJS module
You can generate parsers programatically from JavaScript as well. Assuming Jison is in your commonjs environment's load path:
// mygenerator.js
var Parser = require("jison").Parser;
// a grammar in JSON
var grammar = {
"lex": {
"rules": [
["\\s+", "/* skip whitespace */"],
["[a-f0-9]+", "return 'HEX';"]
]
},
"bnf": {
"hex_strings" :[ "hex_strings HEX",
"HEX" ]
}
};
// `grammar` can also be a string that uses jison's grammar format
var parser = new Parser(grammar);
// generate source, ready to be written to disk
var parserSource = parser.generate();
// you can also use the parser directly from memory
// returns true
parser.parse("adfe34bc e82a");
// throws lexical error
parser.parse("adfe34bc zxg");
More Documentation
For more information on creating grammars and using the generated parsers, read the documentation.
How to contribute
See CONTRIBUTING.md for contribution guidelines, how to run the tests, etc.
Projects using Jison
View them on the wiki, or add your own.
Contributors
Special thanks to Jarred Ligatti, Manuel E. Bermúdez
License
Copyright (c) 2009-2014 Zachary Carter
Permission is hereby granted, free of
charge, to any person obtaining a
copy of this software and associated
documentation files (the "Software"),
to deal in the Software without
restriction, including without
limitation the rights to use, copy,
modify, merge, publish, distribute,
sublicense, and/or sell copies of the
Software, and to permit persons to
whom the Software is furnished to do
so, subject to the following
conditions:The above copyright notice and this
permission notice shall be included
in all copies or substantial portions
of the Software.THE SOFTWARE IS PROVIDED "AS IS",
WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED
TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF
CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.