Package Exports

dag-json

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (dag-json) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

dag-json

Compress a json using tree to dag transformation. For example:

    ajson = require "dag-json"

    #lets generate a bigger json
    big = (f=(x)->if(x)then(ff=f(x-1);{a:ff,b:ff})else[1,2]) 16
    console.log (JSON.stringify big).length
    # 1048565

    console.log packed = ajson.pack big
    #{ '$0': [ 1, 2 ],
    #  '$1': { a: '$0', b: '$0' },
    #  '$2': { a: '$1', b: '$1' },
    #  '$3': { a: '$2', b: '$2' },
    #  '$4': { a: '$3', b: '$3' },
    #  '$5': { a: '$4', b: '$4' },
    #  '$6': { a: '$5', b: '$5' },
    #  '$7': { a: '$6', b: '$6' },
    #  '$8': { a: '$7', b: '$7' },
    #  '$9': { a: '$8', b: '$8' },
    #  '$a': { a: '$9', b: '$9' },
    #  '$b': { a: '$a', b: '$a' },
    #  '$c': { a: '$b', b: '$b' },
    #  '$d': { a: '$c', b: '$c' },
    #  '$e': { a: '$d', b: '$d' },
    #  '$f': { a: '$e', b: '$e' },
    #  '$g': { a: '$f', b: '$f' } }
    console.log (JSON.stringify packed).length
    # 412

    unpacked = ajson.unpack packed
    console.log (JSON.stringify unpacked) is JSON.stringify big
    # true

Thus, common subtrees are extracted and reused.

Also, if you want just aliasing, you can do something like that:

    {pack, unpack, unalias} = require "./index"
    a =
        "$":
            "$a": a: "$b", b: 12
            "$b": [1,2,3]
        hey: ["$a", "$b", "$a", 12]
        ho: a: "$a", b: "$a"

    console.log JSON.stringify unalias a
    # {"hey":[{"a":[1,2,3],"b":12},[1,2,3],{"a":[1,2,3],"b":12},12],
    #  "ho":{"a":{"a":[1,2,3],"b":12},"b":{"a":[1,2,3],"b":12}}}