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 jsonutil = require("json.util")
   8 local huge = require("math").huge
   9
  10 local _ENV = nil
  11
  12 local defaultOptions = {
  13         nan = true,
  14         inf = true
  15 }
  16
  17 local modeOptions = {}
  18 modeOptions.strict = {
  19         nan = false,
  20         inf = false
  21 }
  22
  23 local function mergeOptions(options, mode)
  24         jsonutil.doOptionMerge(options, false, 'number', defaultOptions, mode and modeOptions[mode])
  25 end
  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 jsonutil.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         mergeOptions = mergeOptions,
  55         getEncoder = getEncoder
  56 }
  57
  58 return number