src/json/encode/array.lua

   1 local jsonencode = require("json.encode")
   2
   3 local type = type
   4 local pairs = pairs
   5 local assert = assert
   6
   7 local table_concat = table.concat
   8 local math_floor, math_modf = math.floor, math.modf
   9
  10 module("json.encode.array")
  11
  12 function isArray(val, options)
  13         local externalIsArray = options and options.array and options.array.isArray
  14         local isEncodable = jsonencode.isEncodable
  15
  16         if externalIsArray then
  17                 local ret = externalIsArray(val)
  18                 if ret == true or ret == false then
  19                         return ret
  20                 end
  21         end
  22         -- Use the 'n' element if it's a number
  23         if type(val.n) == 'number' and math_floor(val.n) == val.n and val.n >= 1 then
  24                 return true
  25         end
  26         local len = #val
  27         for k,v in pairs(val) do
  28                 if type(k) ~= 'number' then
  29                         return false
  30                 end
  31                 local _, decim = math_modf(k)
  32                 if not (decim == 0 and 1<=k) then
  33                         return false
  34                 end
  35                 assert(isEncodable(v, options), "Invalid array element type:" .. type(v))
  36                 if k > len then -- Use Lua's length as absolute determiner
  37                         return false
  38                 end
  39         end
  40
  41         return true
  42 end
  43
  44 function encode(tab, options)
  45         local encodeValue = jsonencode.encodeValue
  46         local retVal = {}
  47         for i = 1,(tab.n or #tab) do
  48                 retVal[#retVal + 1] = encodeValue(tab[i], options)
  49         end
  50         return '[' .. table_concat(retVal, ',') .. ']'
  51 end