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 _ENV = nil
  21
  22 local function get_invalid_character_info(input, index)
  23         local parsed = input:sub(1, index)
  24         local bad_character = input:sub(index, index)
  25         local _, line_number = parsed:gsub('\n',{})
  26         local last_line = parsed:match("\n([^\n]+.)$") or parsed
  27         return line_number, #last_line, bad_character, last_line
  28 end
  29
  30 local function build_report(msg)
  31         local fmt = msg:gsub("%%", "%%%%") .. " @ character: %i %i:%i [%s] line:\n%s"
  32         return lpeg.P(function(data, pos)
  33                 local line, line_index, bad_char, last_line = get_invalid_character_info(data, pos)
  34                 local text = fmt:format(pos, line, line_index, bad_char, last_line)
  35                 error(text)
  36         end) * 1
  37 end
  38 local function unexpected()
  39         local msg = "unexpected character"
  40         return build_report(msg)
  41 end
  42 local function expected(...)
  43         local items = {...}
  44         local msg
  45         if #items > 1 then
  46                 msg = "expected one of '" .. table_concat(items, "','") .. "'"
  47         else
  48                 msg = "expected '" .. items[1] .. "'"
  49         end
  50         return build_report(msg)
  51 end
  52 local function denied(item, option)
  53         local msg
  54         if option then
  55                 msg = ("'%s' denied by option set '%s'"):format(item, option)
  56         else
  57                 msg = ("'%s' denied"):format(item)
  58         end
  59         return build_report(msg)
  60 end
  61
  62 -- 09, 0A, 0B, 0C, 0D, 20
  63 local ascii_space = lpeg.S("\t\n\v\f\r ")
  64 local unicode_space
  65 do
  66         local chr = string_char
  67         local u_space = ascii_space
  68         -- \u0085 \u00A0
  69         u_space = u_space + lpeg.P(chr(0xC2)) * lpeg.S(chr(0x85) .. chr(0xA0))
  70         -- \u1680 \u180E
  71         u_space = u_space + lpeg.P(chr(0xE1)) * (lpeg.P(chr(0x9A, 0x80)) + chr(0xA0, 0x8E))
  72         -- \u2000 - \u200A, also 200B
  73         local spacing_end = ""
  74         for i = 0x80,0x8b do
  75                 spacing_end = spacing_end .. chr(i)
  76         end
  77         -- \u2028 \u2029 \u202F
  78         spacing_end = spacing_end .. chr(0xA8) .. chr(0xA9) .. chr(0xAF)
  79         u_space = u_space + lpeg.P(chr(0xE2, 0x80)) * lpeg.S(spacing_end)
  80         -- \u205F
  81         u_space = u_space + lpeg.P(chr(0xE2, 0x81, 0x9F))
  82         -- \u3000
  83         u_space = u_space + lpeg.P(chr(0xE3, 0x80, 0x80))
  84         -- BOM \uFEFF
  85         u_space = u_space + lpeg.P(chr(0xEF, 0xBB, 0xBF))
  86         unicode_space = u_space
  87 end
  88
  89 local identifier = lpeg.R("AZ","az","__") * lpeg.R("AZ","az", "__", "09") ^0
  90
  91 local hex = lpeg.R("09","AF","af")
  92 local hexpair = hex * hex
  93
  94 local comments = {
  95         cpp = lpeg.P("//") * (1 - lpeg.P("\n"))^0 * lpeg.P("\n"),
  96         c = lpeg.P("/*") * (1 - lpeg.P("*/"))^0 * lpeg.P("*/")
  97 }
  98
  99 local comment = comments.cpp + comments.c
 100
 101 local ascii_ignored = (ascii_space + comment)^0
 102
 103 local unicode_ignored = (unicode_space + comment)^0
 104
 105 -- Parse the lpeg version skipping patch-values
 106 -- LPEG <= 0.7 have no version value... so 0.7 is value
 107 local DecimalLpegVersion = lpeg.version and tonumber(lpeg.version():match("^(%d+%.%d+)")) or 0.7
 108
 109 local function setObjectKeyForceNumber(t, key, value)
 110         key = tonumber(key) or key
 111         return rawset(t, key, value)
 112 end
 113
 114 local util = {
 115         unexpected = unexpected,
 116         expected = expected,
 117         denied = denied,
 118         ascii_space = ascii_space,
 119         unicode_space = unicode_space,
 120         identifier = identifier,
 121         hex = hex,
 122         hexpair = hexpair,
 123         comments = comments,
 124         comment = comment,
 125         ascii_ignored = ascii_ignored,
 126         unicode_ignored = unicode_ignored,
 127         DecimalLpegVersion = DecimalLpegVersion,
 128         get_invalid_character_info = get_invalid_character_info,
 129         setObjectKeyForceNumber = setObjectKeyForceNumber
 130 }
 131
 132 return util