lua/json/encode/others.lua

   1 --[[
   2         Licensed according to the included 'LICENSE' document
   3         Author: Thomas Harning Jr <harningt@gmail.com>
   4 ]]
   5 local tostring = tostring
   6
   7 local assert = assert
   8 local jsonutil = require("json.util")
   9 local util_merge = require("json.util").merge
  10 local type = type
  11
  12 local is_52 = _VERSION == "Lua 5.2"
  13 local _G = _G
  14
  15 if is_52 then
  16         _ENV = nil
  17 end
  18
  19 -- Shortcut that works
  20 local encodeBoolean = tostring
  21
  22 local defaultOptions = {
  23         allowUndefined = true,
  24         null = jsonutil.null,
  25         undefined = jsonutil.undefined
  26 }
  27
  28 local default = nil -- Let the buildCapture optimization take place
  29 local strict = {
  30         allowUndefined = false
  31 }
  32
  33 local function getEncoder(options)
  34         options = options and util_merge({}, defaultOptions, options) or defaultOptions
  35         local function encodeOthers(value, state)
  36                 if value == options.null then
  37                         return 'null'
  38                 elseif value == options.undefined then
  39                         assert(options.allowUndefined, "Invalid value: Unsupported 'Undefined' parameter")
  40                         return 'undefined'
  41                 else
  42                         return false
  43                 end
  44         end
  45         local function encodeBoolean(value, state)
  46                 return value and 'true' or 'false'
  47         end
  48         local nullType = type(options.null)
  49         local undefinedType = options.undefined and type(options.undefined)
  50         -- Make sure that all of the types handled here are handled
  51         local ret = {
  52                 boolean = encodeBoolean,
  53                 ['nil'] = function() return 'null' end,
  54                 [nullType] = encodeOthers
  55         }
  56         if undefinedType then
  57                 ret[undefinedType] = encodeOthers
  58         end
  59         return ret
  60 end
  61
  62 local others = {
  63         encodeBoolean = encodeBoolean,
  64         default = default,
  65         strict = strict,
  66         getEncoder = getEncoder
  67 }
  68
  69 if not is_52 then
  70         _G.json = _G.json or {}
  71         _G.json.encode = _G.json.encode or {}
  72         _G.json.encode.others = others
  73 end
  74
  75 return others