lua/json/encode/object.lua

   1 --[[
   2         Licensed according to the included 'LICENSE' document
   3         Author: Thomas Harning Jr <harningt@gmail.com>
   4 ]]
   5 local pairs = pairs
   6 local assert = assert
   7
   8 local type = type
   9 local tostring = tostring
  10
  11 local table_concat = require("table").concat
  12 local jsonutil = require("json.util")
  13
  14 local _ENV = nil
  15
  16 local defaultOptions = {
  17 }
  18
  19 local modeOptions = {}
  20
  21 local function mergeOptions(options, mode)
  22         jsonutil.doOptionMerge(options, false, 'object', defaultOptions, mode and modeOptions[mode])
  23 end
  24
  25 --[[
  26         Cleanup function to unmark a value as in the encoding process and return
  27         trailing results
  28 ]]
  29 local function unmarkAfterEncode(tab, state, ...)
  30         state.already_encoded[tab] = nil
  31         return ...
  32 end
  33 --[[
  34         Encode a table as a JSON Object ( keys = strings, values = anything else )
  35 ]]
  36 local function encodeTable(tab, options, state)
  37         -- Make sure this value hasn't been encoded yet
  38         state.check_unique(tab)
  39         local encode = state.encode
  40         local compositeEncoder = state.outputEncoder.composite
  41         local valueEncoder = [[
  42         local first = true
  43         for k, v in pairs(composite) do
  44                 local ti = type(k)
  45                 assert(ti == 'string' or ti == 'number' or ti == 'boolean', "Invalid object index type: " .. ti)
  46                 local name = encode(tostring(k), state, true)
  47                 if first then
  48                         first = false
  49                 else
  50                         name = ',' .. name
  51                 end
  52                 PUTVALUE(name .. ':')
  53                 local val = encode(v, state)
  54                 val = val or ''
  55                 if val then
  56                         PUTVALUE(val)
  57                 end
  58         end
  59         ]]
  60         return unmarkAfterEncode(tab, state, compositeEncoder(valueEncoder, '{', '}', nil, tab, encode, state))
  61 end
  62
  63 local function getEncoder(options)
  64         options = options and jsonutil.merge({}, defaultOptions, options) or defaultOptions
  65         return {
  66                 table = function(tab, state)
  67                         return encodeTable(tab, options, state)
  68                 end
  69         }
  70 end
  71
  72 local object = {
  73         mergeOptions = mergeOptions,
  74         getEncoder = getEncoder
  75 }
  76
  77 return object