lua/json/encode/number.lua

   1 --[[
   2         Licensed according to the included 'LICENSE' document
   3         Author: Thomas Harning Jr <harningt@gmail.com>
   4 ]]
   5 local tostring = tostring
   6 local assert = assert
   7 local util = require("json.util")
   8 local huge = require("math").huge
   9
  10 local is_52 = _VERSION == "Lua 5.2"
  11 local _G = _G
  12
  13 if is_52 then
  14         _ENV = nil
  15 end
  16
  17 local defaultOptions = {
  18         nan = true,
  19         inf = true
  20 }
  21
  22 local default = nil -- Let the buildCapture optimization take place
  23 local strict = {
  24         nan = false,
  25         inf = false
  26 }
  27
  28 local function encodeNumber(number, options)
  29         if number ~= number then
  30                 assert(options.nan, "Invalid number: NaN not enabled")
  31                 return "NaN"
  32         end
  33         if number == huge then
  34                 assert(options.inf, "Invalid number: Infinity not enabled")
  35                 return "Infinity"
  36         end
  37         if number == -huge then
  38                 assert(options.inf, "Invalid number: Infinity not enabled")
  39                 return "-Infinity"
  40         end
  41         return tostring(number)
  42 end
  43
  44 local function getEncoder(options)
  45         options = options and util.merge({}, defaultOptions, options) or defaultOptions
  46         return {
  47                 number = function(number, state)
  48                         return encodeNumber(number, options)
  49                 end
  50         }
  51 end
  52
  53 local number = {
  54         default = default,
  55         strict = strict,
  56         getEncoder = getEncoder
  57 }
  58
  59 if not is_52 then
  60         _G.json = _G.json or {}
  61         _G.json.encode = _G.json.encode or {}
  62         _G.json.encode.number = number
  63 end
  64
  65 return number