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 denied(item, option)
  43         local msg
  44         if option then
  45                 msg = ("'%s' denied by option set '%s'"):format(item, option)
  46         else
  47                 msg = ("'%s' denied"):format(item)
  48         end
  49         return build_report(msg)
  50 end
  51
  52 -- 09, 0A, 0B, 0C, 0D, 20
  53 local ascii_space = lpeg.S("\t\n\v\f\r ")
  54 local unicode_space
  55 do
  56         local chr = string_char
  57         local u_space = ascii_space
  58         -- \u0085 \u00A0
  59         u_space = u_space + lpeg.P(chr(0xC2)) * lpeg.S(chr(0x85) .. chr(0xA0))
  60         -- \u1680 \u180E
  61         u_space = u_space + lpeg.P(chr(0xE1)) * (lpeg.P(chr(0x9A, 0x80)) + chr(0xA0, 0x8E))
  62         -- \u2000 - \u200A, also 200B
  63         local spacing_end = ""
  64         for i = 0x80,0x8b do
  65                 spacing_end = spacing_end .. chr(i)
  66         end
  67         -- \u2028 \u2029 \u202F
  68         spacing_end = spacing_end .. chr(0xA8) .. chr(0xA9) .. chr(0xAF)
  69         u_space = u_space + lpeg.P(chr(0xE2, 0x80)) * lpeg.S(spacing_end)
  70         -- \u205F
  71         u_space = u_space + lpeg.P(chr(0xE2, 0x81, 0x9F))
  72         -- \u3000
  73         u_space = u_space + lpeg.P(chr(0xE3, 0x80, 0x80))
  74         -- BOM \uFEFF
  75         u_space = u_space + lpeg.P(chr(0xEF, 0xBB, 0xBF))
  76         unicode_space = u_space
  77 end
  78
  79 local identifier = lpeg.R("AZ","az","__") * lpeg.R("AZ","az", "__", "09") ^0
  80
  81 local hex = lpeg.R("09","AF","af")
  82 local hexpair = hex * hex
  83
  84 local comments = {
  85         cpp = lpeg.P("//") * (1 - lpeg.P("\n"))^0 * lpeg.P("\n"),
  86         c = lpeg.P("/*") * (1 - lpeg.P("*/"))^0 * lpeg.P("*/")
  87 }
  88
  89 local comment = comments.cpp + comments.c
  90
  91 local ascii_ignored = (ascii_space + comment)^0
  92
  93 local unicode_ignored = (unicode_space + comment)^0
  94
  95 -- Parse the lpeg version skipping patch-values
  96 -- LPEG <= 0.7 have no version value... so 0.7 is value
  97 local DecimalLpegVersion = lpeg.version and tonumber(lpeg.version():match("^(%d+%.%d+)")) or 0.7
  98
  99 local function setObjectKeyForceNumber(t, key, value)
 100         key = tonumber(key) or key
 101         return rawset(t, key, value)
 102 end
 103
 104 local util = {
 105         unexpected = unexpected,
 106         denied = denied,
 107         ascii_space = ascii_space,
 108         unicode_space = unicode_space,
 109         identifier = identifier,
 110         hex = hex,
 111         hexpair = hexpair,
 112         comments = comments,
 113         comment = comment,
 114         ascii_ignored = ascii_ignored,
 115         unicode_ignored = unicode_ignored,
 116         DecimalLpegVersion = DecimalLpegVersion,
 117         get_invalid_character_info = get_invalid_character_info,
 118         setObjectKeyForceNumber = setObjectKeyForceNumber
 119 }
 120
 121 return util