JSON parser/encoder for Lua Parses JSON using LPEG for speed and flexibility. Depending on parser/encoder options, various values are preserved as best as possible.
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Latest commit b47d381 Sep 10, 2016 @harningt committed on GitHub Merge pull request #36 from retroverse/master
Update README to use MarkDown



JSON Parser/Constructor for Lua


Thomas Harning Jr. harningt@gmail.com

Source code:


Bug reports:

http://github.com/harningt/luajson harningt@gmail.com


Lua 5.1, 5.2, 5.3, LuaJIT 2.0, or LuaJIT 2.1 LPeg (Tested with 0.7, 0.8, 0.9, 0.10, 0.12rc2, 1.0) For regressionTest: lfs (Tested with 1.6.3)

For lunit-tests:

lunitx >= 0.8


LPeg 0.11 may not work - it crashed during my initial tests, it is not in the test matrix.

Lua versions tested recently:

  • Lua 5.1.5
  • Lua 5.2.4
  • Lua 5.3.2
  • LuaJIT-2.0.4
  • LuaJIT-2.1.0-beta2


All-but tests: MIT-style, See LICENSE for details tests/*: Public Domain / MIT - whichever is least restrictive

Module/Function overview:

json.encode (callable module referencing json.encode.encode)

encode ( value : ANY-valid )

Takes in a JSON-encodable value and returns the JSON-encoded text Valid input types:

  • table
  • array-like table (spec below)
  • string
  • number
  • boolean
  • 'null' - represented by json.util.null

Table keys (string,number,boolean) are encoded as strings, others are erroneus Table values are any valid input-type Array-like tables are converted into JSON arrays... Position 1 maps to JSON Array position 0

isEncodable ( value : ANY )

Returns a boolean stating whether is is encodeable or not NOTE: Tables/arrays are not deeply inspected

json.decode (callable module referencing json.decode.decode)

decode (data : string, strict : optional boolean)

Takes in a string of JSON data and converts it into a Lua object If 'strict' is set, then the strict JSON rule-set is used


printValue (tab : ANY, name : string)

recursively prints out all object values - if duplicates found, reference printed


Reference value to represent 'null' in a well-defined way to allow for null values to be inserted into an array/table

merge (t : table, ... : tables)

Shallow-merges a sequence of tables onto table t by iterating over each using pairs and assigning.


parsing test suite from JSON_checker project of http://www.json.org/ No listed license for these files in their package.