ohm-grammar-json

JSON parser written using the Ohm parsing framework.

Installation

npm install ohm-grammar-json

Usage

var json = require('ohm-grammar-json');

Analogous to Javascript's built in JSON.parse:

json.parse('{"a": "b"}')

The Ohm grammar and semantics objects are available:

json.grammar
json.semantics

Match json and return an Ohm match stucture:

json.grammar.match('{"a": "b"}') // Returns a grammar object
json.grammar.match('{"a": "b"}').succeeded() // true
json.grammar.match('["Unclosed array"').succeeded() // false
json.grammar.match('["Unclosed array"').message // Error message

Testing

# Pull in submodules (nativejson-benchmark) 
git submodule init --update
 
# Install dev dependencies 
npm install
 
# Run tests 
npm test

Pretty Printer example

There is an example JSON pretty printer implemented in examples/pretty-printer.js. The purpose of this example is to demonstrate

1. Creating a new semantic operation on top of an existing grammar.
2. Writing a semantic operation that depends on a context.

Example usage:

var PrettyPrinter = require('ohm-grammar-json/examples/pretty-printer');
 
var str = PrettyPrinter.prettyPrint('{"a":"b","c":[1,2,[true,false,null],6.7]}');
 
console.log(str);

Output:

{
  "a": "b",
  "c": [
    1,
    2,
    [
      true,
      false,
      null
    ],
    6.7
  ]
}

Status

This package is intended as a demonstration of the Ohm parsing framework. If you want to parse or pretty print JSON in javascript, I recommend using the built in JSON.parse and JSON.stringify functions.

This project is intended to conform to ECMA 404 and as far as I know, it does.