A lightweight JSON library for Lua

Features

Implemented in pure Lua: works with 5.1, 5.2, 5.3 and JIT
Fast: generally outperforms other pure Lua JSON implementations (benchmark scripts)
Tiny: around 290sloc, 9kb
Proper error messages, eg: expected '}' or ',' at line 203 col 30

Usage

The json.lua file should be dropped into an existing project and required by it:

json = require "json"

The library provides the following functions:

Returns a string representing value encoded in JSON.

json.encode({ 1, 2, 3, { x = 10 } }) -- Returns '[1,2,3,{"x":10}]'

Returns a value representing the decoded JSON string.

json.decode('[1,2,3,{"x":10}]') -- Returns { 1, 2, 3, { x = 10 } }

Trying to encode values which are unrepresentable in JSON will never result in type conversion or other magic: sparse arrays, tables with mixed key types or invalid numbers (NaN, -inf, inf) will raise an error
null values contained within an array or object are converted to nil and are therefore lost upon decoding
Pretty encoding is not supported, json.encode() only encodes to a compact format

This library is free software; you can redistribute it and/or modify it under the terms of the MIT license. See LICENSE for details.