lua/json/decode/others.lua

   1 --[[
   2         Licensed according to the included 'LICENSE' document
   3         Author: Thomas Harning Jr <harningt@gmail.com>
   4 ]]
   5 local lpeg = require("lpeg")
   6 local jsonutil = require("json.util")
   7 local util = require("json.decode.util")
   8
   9 -- Container module for other JavaScript types (bool, null, undefined)
  10 module("json.decode.others")
  11
  12 -- For null and undefined, use the util.null value to preserve null-ness
  13 local booleanCapture =
  14         lpeg.P("true") * lpeg.Cc(true)
  15         + lpeg.P("false") * lpeg.Cc(false)
  16
  17 local nullCapture = lpeg.P("null")
  18 local undefinedCapture = lpeg.P("undefined")
  19
  20 local defaultOptions = {
  21         allowUndefined = true,
  22         null = jsonutil.null,
  23         undefined = jsonutil.undefined
  24 }
  25
  26 default = nil -- Let the buildCapture optimization take place
  27 strict = {
  28         allowUndefined = false
  29 }
  30
  31 local function buildCapture(options)
  32         options = options and jsonutil.merge({}, defaultOptions, options) or defaultOptions
  33         local valueCapture = (
  34                 booleanCapture
  35                 + nullCapture * lpeg.Cc(options.null)
  36         )
  37         if options.allowUndefined then
  38                 valueCapture = valueCapture + undefinedCapture * lpeg.Cc(options.undefined)
  39         end
  40         return valueCapture
  41 end
  42
  43 function load_types(options, global_options, grammar)
  44         local capture = buildCapture(options)
  45         util.append_grammar_item(grammar, "VALUE", capture)
  46 end