mojangson

A mojangson parser written in node.js

Usage no npm install needed!

<script type="module">
  import mojangson from 'https://cdn.skypack.dev/mojangson';
</script>

README

node-mojangson

NPM version CI

node-mojangson is a mojangson parser.

Mojangson specification

Mojangson is mojang's variant of json. It is basically json with the following changes :

  • array can be indexed (example : [0:"v1",1:"v2",2:"v3"])
  • array and object can have trailing comma (example : [5,4,3,] and {"a":5,"b":6,})
  • there can be string without quote (example : {mykey:myvalue})
  • numbers can be suffixed by b, s, l, f, d, i or the same in upper case (example : {number:5b})
  • mojangson stays a superset of json : every json is a mojangson

Reference https://minecraft.gamepedia.com/Commands#Data_tags

Parser

This parser is build using nearley.

See the grammar and the examples in the test for more information.

Usage

Usage example :

const mojangson = require('mojangson')

const data = mojangson.parse('{mykey:myvalue}')

// print the parsed data
console.log(data)

// print the simplified data
condole.log(mojangson.simplify(data))

The provided method mojangson.parse return a javascript object corresponding to the mojangson passed in input.

mojangson.simplify returns a simplified representation : keep only the value to remove one level. This loses the types so you cannot use the resulting representation to write it back.

mojangson.stringify will take a js object with types and values for mojangson and make it into a normalized mojangson string

const mojangson = require('mojangson')
const data = mojangson.stringify({ type: 'list', value: { type: 'string', value: [ 'z1', 'z2' ] } })
console.log(data) // => [z1,z2]

Another example, the provided method mojangson.normalize takes a string of mojangson and normalizes it in the shortest way to retain all data. Comparing it to the original will tell you if you have the shortest equivalent to a string of mojangson.

const mojangson = require('mojangson')
const original = '[0:"z1",1:"z2"]'
const data = mojangson.normalize(original)
console.log(data) // => [z1,z2]
const optimized = original === data
console.log(optimized) // => false

History

2.0.2

  • fixes issue where strings starting with a number would be parsed as a number (@U9G)

2.0.1

  • fix escaping some chars in mojangson.stringify (@U9G)
  • update grammar for unicode escaped strings (@U9G)
  • fix parsing of escaped characters (@Majorblake)

2.0.0

  • Changes output format to include types (@Karang)
  • add simplify function
  • Add stringify function to go back to mojangson (@U9G)

1.1.1

  • Fix empty string parsing (thanks @IdanHo)

1.1.0

  • switch to nearley parser for a better handling for mojangson (thanks @Karang)

1.0.0

  • stop printing error

0.2.4

  • add support for double and int

0.2.3

  • fix release about grammar.js still containing the cli

0.2.2

  • disable jison cli to make mojangson compatible with browserify

0.2.1

  • fix state conflict due to recent trailing comma fix

0.2.0

  • Rename npm package to mojangson
  • fix trailing comma in arrays

0.1.1

  • better error displaying

0.1

  • First release, basic functionality