lua/json/decode/util.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 select = select
   7 local pairs, ipairs = pairs, ipairs
   8 local tonumber = tonumber
   9 local string_char = require("string").char
  10 local rawset = rawset
  11 local jsonutil = require("json.util")
  12
  13 local error = error
  14 local setmetatable = setmetatable
  15
  16 local table_concat = require("table").concat
  17
  18 local merge = require("json.util").merge
  19
  20 local type = type
  21
  22 local _ENV = nil
  23
  24 local function get_invalid_character_info(input, index)
  25         local parsed = input:sub(1, index)
  26         local bad_character = input:sub(index, index)
  27         local _, line_number = parsed:gsub('\n',{})
  28         local last_line = parsed:match("\n([^\n]+.)$") or parsed
  29         return line_number, #last_line, bad_character, last_line
  30 end
  31
  32 local function build_report(msg)
  33         local fmt = msg:gsub("%%", "%%%%") .. " @ character: %i %i:%i [%s] line:\n%s"
  34         return lpeg.P(function(data, pos)
  35                 local line, line_index, bad_char, last_line = get_invalid_character_info(data, pos)
  36                 local text = fmt:format(pos, line, line_index, bad_char, last_line)
  37                 error(text)
  38         end) * 1
  39 end
  40 local function unexpected()
  41         local msg = "unexpected character"
  42         return build_report(msg)
  43 end
  44 local function denied(item, option)
  45         local msg
  46         if option then
  47                 msg = ("'%s' denied by option set '%s'"):format(item, option)
  48         else
  49                 msg = ("'%s' denied"):format(item)
  50         end
  51         return build_report(msg)
  52 end
  53
  54 -- 09, 0A, 0B, 0C, 0D, 20
  55 local ascii_space = lpeg.S("\t\n\v\f\r ")
  56 local unicode_space
  57 do
  58         local chr = string_char
  59         local u_space = ascii_space
  60         -- \u0085 \u00A0
  61         u_space = u_space + lpeg.P(chr(0xC2)) * lpeg.S(chr(0x85) .. chr(0xA0))
  62         -- \u1680 \u180E
  63         u_space = u_space + lpeg.P(chr(0xE1)) * (lpeg.P(chr(0x9A, 0x80)) + chr(0xA0, 0x8E))
  64         -- \u2000 - \u200A, also 200B
  65         local spacing_end = ""
  66         for i = 0x80,0x8b do
  67                 spacing_end = spacing_end .. chr(i)
  68         end
  69         -- \u2028 \u2029 \u202F
  70         spacing_end = spacing_end .. chr(0xA8) .. chr(0xA9) .. chr(0xAF)
  71         u_space = u_space + lpeg.P(chr(0xE2, 0x80)) * lpeg.S(spacing_end)
  72         -- \u205F
  73         u_space = u_space + lpeg.P(chr(0xE2, 0x81, 0x9F))
  74         -- \u3000
  75         u_space = u_space + lpeg.P(chr(0xE3, 0x80, 0x80))
  76         -- BOM \uFEFF
  77         u_space = u_space + lpeg.P(chr(0xEF, 0xBB, 0xBF))
  78         unicode_space = u_space
  79 end
  80
  81 local identifier = lpeg.R("AZ","az","__") * lpeg.R("AZ","az", "__", "09") ^0
  82
  83 local hex = lpeg.R("09","AF","af")
  84 local hexpair = hex * hex
  85
  86 local comments = {
  87         cpp = lpeg.P("//") * (1 - lpeg.P("\n"))^0 * lpeg.P("\n"),
  88         c = lpeg.P("/*") * (1 - lpeg.P("*/"))^0 * lpeg.P("*/")
  89 }
  90
  91 local comment = comments.cpp + comments.c
  92
  93 local ascii_ignored = (ascii_space + comment)^0
  94
  95 local unicode_ignored = (unicode_space + comment)^0
  96
  97 -- Parse the lpeg version skipping patch-values
  98 -- LPEG <= 0.7 have no version value... so 0.7 is value
  99 -- LPEG >= 1.1 uses a string for the version instead of function
 100 local DecimalLpegVersion = lpeg.version
 101                 and tonumber(
 102                         (type(lpeg.version) == "string" and lpeg.version or lpeg.version()):match("(%d+%.%d+)")
 103                 )
 104         or 0.7
 105
 106 local function setObjectKeyForceNumber(t, key, value)
 107         key = tonumber(key) or key
 108         return rawset(t, key, value)
 109 end
 110
 111 local util = {
 112         unexpected = unexpected,
 113         denied = denied,
 114         ascii_space = ascii_space,
 115         unicode_space = unicode_space,
 116         identifier = identifier,
 117         hex = hex,
 118         hexpair = hexpair,
 119         comments = comments,
 120         comment = comment,
 121         ascii_ignored = ascii_ignored,
 122         unicode_ignored = unicode_ignored,
 123         DecimalLpegVersion = DecimalLpegVersion,
 124         get_invalid_character_info = get_invalid_character_info,
 125         setObjectKeyForceNumber = setObjectKeyForceNumber
 126 }
 127
 128 return util