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authorlookshe <github@lookshe.org>2016-01-04 23:48:03 +0100
committerlookshe <github@lookshe.org>2016-01-04 23:48:03 +0100
commitd399f6cdafee4831a1691dffdceb57fde2eb3679 (patch)
tree9bb6d4449c0404f7b9e0f8b0a886d70fb8d703e4 /prosody-module/mod_http_upload_external/dkjson.lua
parentce98933ee90b4e0e7ec1ce30cb02c9d04f023970 (diff)
initial implementation of module for prosody, not tested yet
Diffstat (limited to 'prosody-module/mod_http_upload_external/dkjson.lua')
-rw-r--r--prosody-module/mod_http_upload_external/dkjson.lua714
1 files changed, 714 insertions, 0 deletions
diff --git a/prosody-module/mod_http_upload_external/dkjson.lua b/prosody-module/mod_http_upload_external/dkjson.lua
new file mode 100644
index 0000000..fa50b9f
--- /dev/null
+++ b/prosody-module/mod_http_upload_external/dkjson.lua
@@ -0,0 +1,714 @@
+-- Module options:
+local always_try_using_lpeg = true
+local register_global_module_table = false
+local global_module_name = 'json'
+
+--[==[
+
+David Kolf's JSON module for Lua 5.1/5.2
+
+Version 2.5
+
+
+For the documentation see the corresponding readme.txt or visit
+<http://dkolf.de/src/dkjson-lua.fsl/>.
+
+You can contact the author by sending an e-mail to 'david' at the
+domain 'dkolf.de'.
+
+
+Copyright (C) 2010-2013 David Heiko Kolf
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+--]==]
+
+-- global dependencies:
+local pairs, type, tostring, tonumber, getmetatable, setmetatable, rawset =
+ pairs, type, tostring, tonumber, getmetatable, setmetatable, rawset
+local error, require, pcall, select = error, require, pcall, select
+local floor, huge = math.floor, math.huge
+local strrep, gsub, strsub, strbyte, strchar, strfind, strlen, strformat =
+ string.rep, string.gsub, string.sub, string.byte, string.char,
+ string.find, string.len, string.format
+local strmatch = string.match
+local concat = table.concat
+
+local json = { version = "dkjson 2.5" }
+
+if register_global_module_table then
+ _G[global_module_name] = json
+end
+
+local _ENV = nil -- blocking globals in Lua 5.2
+
+pcall (function()
+ -- Enable access to blocked metatables.
+ -- Don't worry, this module doesn't change anything in them.
+ local debmeta = require "debug".getmetatable
+ if debmeta then getmetatable = debmeta end
+end)
+
+json.null = setmetatable ({}, {
+ __tojson = function () return "null" end
+})
+
+local function isarray (tbl)
+ local max, n, arraylen = 0, 0, 0
+ for k,v in pairs (tbl) do
+ if k == 'n' and type(v) == 'number' then
+ arraylen = v
+ if v > max then
+ max = v
+ end
+ else
+ if type(k) ~= 'number' or k < 1 or floor(k) ~= k then
+ return false
+ end
+ if k > max then
+ max = k
+ end
+ n = n + 1
+ end
+ end
+ if max > 10 and max > arraylen and max > n * 2 then
+ return false -- don't create an array with too many holes
+ end
+ return true, max
+end
+
+local escapecodes = {
+ ["\""] = "\\\"", ["\\"] = "\\\\", ["\b"] = "\\b", ["\f"] = "\\f",
+ ["\n"] = "\\n", ["\r"] = "\\r", ["\t"] = "\\t"
+}
+
+local function escapeutf8 (uchar)
+ local value = escapecodes[uchar]
+ if value then
+ return value
+ end
+ local a, b, c, d = strbyte (uchar, 1, 4)
+ a, b, c, d = a or 0, b or 0, c or 0, d or 0
+ if a <= 0x7f then
+ value = a
+ elseif 0xc0 <= a and a <= 0xdf and b >= 0x80 then
+ value = (a - 0xc0) * 0x40 + b - 0x80
+ elseif 0xe0 <= a and a <= 0xef and b >= 0x80 and c >= 0x80 then
+ value = ((a - 0xe0) * 0x40 + b - 0x80) * 0x40 + c - 0x80
+ elseif 0xf0 <= a and a <= 0xf7 and b >= 0x80 and c >= 0x80 and d >= 0x80 then
+ value = (((a - 0xf0) * 0x40 + b - 0x80) * 0x40 + c - 0x80) * 0x40 + d - 0x80
+ else
+ return ""
+ end
+ if value <= 0xffff then
+ return strformat ("\\u%.4x", value)
+ elseif value <= 0x10ffff then
+ -- encode as UTF-16 surrogate pair
+ value = value - 0x10000
+ local highsur, lowsur = 0xD800 + floor (value/0x400), 0xDC00 + (value % 0x400)
+ return strformat ("\\u%.4x\\u%.4x", highsur, lowsur)
+ else
+ return ""
+ end
+end
+
+local function fsub (str, pattern, repl)
+ -- gsub always builds a new string in a buffer, even when no match
+ -- exists. First using find should be more efficient when most strings
+ -- don't contain the pattern.
+ if strfind (str, pattern) then
+ return gsub (str, pattern, repl)
+ else
+ return str
+ end
+end
+
+local function quotestring (value)
+ -- based on the regexp "escapable" in https://github.com/douglascrockford/JSON-js
+ value = fsub (value, "[%z\1-\31\"\\\127]", escapeutf8)
+ if strfind (value, "[\194\216\220\225\226\239]") then
+ value = fsub (value, "\194[\128-\159\173]", escapeutf8)
+ value = fsub (value, "\216[\128-\132]", escapeutf8)
+ value = fsub (value, "\220\143", escapeutf8)
+ value = fsub (value, "\225\158[\180\181]", escapeutf8)
+ value = fsub (value, "\226\128[\140-\143\168-\175]", escapeutf8)
+ value = fsub (value, "\226\129[\160-\175]", escapeutf8)
+ value = fsub (value, "\239\187\191", escapeutf8)
+ value = fsub (value, "\239\191[\176-\191]", escapeutf8)
+ end
+ return "\"" .. value .. "\""
+end
+json.quotestring = quotestring
+
+local function replace(str, o, n)
+ local i, j = strfind (str, o, 1, true)
+ if i then
+ return strsub(str, 1, i-1) .. n .. strsub(str, j+1, -1)
+ else
+ return str
+ end
+end
+
+-- locale independent num2str and str2num functions
+local decpoint, numfilter
+
+local function updatedecpoint ()
+ decpoint = strmatch(tostring(0.5), "([^05+])")
+ -- build a filter that can be used to remove group separators
+ numfilter = "[^0-9%-%+eE" .. gsub(decpoint, "[%^%$%(%)%%%.%[%]%*%+%-%?]", "%%%0") .. "]+"
+end
+
+updatedecpoint()
+
+local function num2str (num)
+ return replace(fsub(tostring(num), numfilter, ""), decpoint, ".")
+end
+
+local function str2num (str)
+ local num = tonumber(replace(str, ".", decpoint))
+ if not num then
+ updatedecpoint()
+ num = tonumber(replace(str, ".", decpoint))
+ end
+ return num
+end
+
+local function addnewline2 (level, buffer, buflen)
+ buffer[buflen+1] = "\n"
+ buffer[buflen+2] = strrep (" ", level)
+ buflen = buflen + 2
+ return buflen
+end
+
+function json.addnewline (state)
+ if state.indent then
+ state.bufferlen = addnewline2 (state.level or 0,
+ state.buffer, state.bufferlen or #(state.buffer))
+ end
+end
+
+local encode2 -- forward declaration
+
+local function addpair (key, value, prev, indent, level, buffer, buflen, tables, globalorder, state)
+ local kt = type (key)
+ if kt ~= 'string' and kt ~= 'number' then
+ return nil, "type '" .. kt .. "' is not supported as a key by JSON."
+ end
+ if prev then
+ buflen = buflen + 1
+ buffer[buflen] = ","
+ end
+ if indent then
+ buflen = addnewline2 (level, buffer, buflen)
+ end
+ buffer[buflen+1] = quotestring (key)
+ buffer[buflen+2] = ":"
+ return encode2 (value, indent, level, buffer, buflen + 2, tables, globalorder, state)
+end
+
+local function appendcustom(res, buffer, state)
+ local buflen = state.bufferlen
+ if type (res) == 'string' then
+ buflen = buflen + 1
+ buffer[buflen] = res
+ end
+ return buflen
+end
+
+local function exception(reason, value, state, buffer, buflen, defaultmessage)
+ defaultmessage = defaultmessage or reason
+ local handler = state.exception
+ if not handler then
+ return nil, defaultmessage
+ else
+ state.bufferlen = buflen
+ local ret, msg = handler (reason, value, state, defaultmessage)
+ if not ret then return nil, msg or defaultmessage end
+ return appendcustom(ret, buffer, state)
+ end
+end
+
+function json.encodeexception(reason, value, state, defaultmessage)
+ return quotestring("<" .. defaultmessage .. ">")
+end
+
+encode2 = function (value, indent, level, buffer, buflen, tables, globalorder, state)
+ local valtype = type (value)
+ local valmeta = getmetatable (value)
+ valmeta = type (valmeta) == 'table' and valmeta -- only tables
+ local valtojson = valmeta and valmeta.__tojson
+ if valtojson then
+ if tables[value] then
+ return exception('reference cycle', value, state, buffer, buflen)
+ end
+ tables[value] = true
+ state.bufferlen = buflen
+ local ret, msg = valtojson (value, state)
+ if not ret then return exception('custom encoder failed', value, state, buffer, buflen, msg) end
+ tables[value] = nil
+ buflen = appendcustom(ret, buffer, state)
+ elseif value == nil then
+ buflen = buflen + 1
+ buffer[buflen] = "null"
+ elseif valtype == 'number' then
+ local s
+ if value ~= value or value >= huge or -value >= huge then
+ -- This is the behaviour of the original JSON implementation.
+ s = "null"
+ else
+ s = num2str (value)
+ end
+ buflen = buflen + 1
+ buffer[buflen] = s
+ elseif valtype == 'boolean' then
+ buflen = buflen + 1
+ buffer[buflen] = value and "true" or "false"
+ elseif valtype == 'string' then
+ buflen = buflen + 1
+ buffer[buflen] = quotestring (value)
+ elseif valtype == 'table' then
+ if tables[value] then
+ return exception('reference cycle', value, state, buffer, buflen)
+ end
+ tables[value] = true
+ level = level + 1
+ local isa, n = isarray (value)
+ if n == 0 and valmeta and valmeta.__jsontype == 'object' then
+ isa = false
+ end
+ local msg
+ if isa then -- JSON array
+ buflen = buflen + 1
+ buffer[buflen] = "["
+ for i = 1, n do
+ buflen, msg = encode2 (value[i], indent, level, buffer, buflen, tables, globalorder, state)
+ if not buflen then return nil, msg end
+ if i < n then
+ buflen = buflen + 1
+ buffer[buflen] = ","
+ end
+ end
+ buflen = buflen + 1
+ buffer[buflen] = "]"
+ else -- JSON object
+ local prev = false
+ buflen = buflen + 1
+ buffer[buflen] = "{"
+ local order = valmeta and valmeta.__jsonorder or globalorder
+ if order then
+ local used = {}
+ n = #order
+ for i = 1, n do
+ local k = order[i]
+ local v = value[k]
+ if v then
+ used[k] = true
+ buflen, msg = addpair (k, v, prev, indent, level, buffer, buflen, tables, globalorder, state)
+ prev = true -- add a seperator before the next element
+ end
+ end
+ for k,v in pairs (value) do
+ if not used[k] then
+ buflen, msg = addpair (k, v, prev, indent, level, buffer, buflen, tables, globalorder, state)
+ if not buflen then return nil, msg end
+ prev = true -- add a seperator before the next element
+ end
+ end
+ else -- unordered
+ for k,v in pairs (value) do
+ buflen, msg = addpair (k, v, prev, indent, level, buffer, buflen, tables, globalorder, state)
+ if not buflen then return nil, msg end
+ prev = true -- add a seperator before the next element
+ end
+ end
+ if indent then
+ buflen = addnewline2 (level - 1, buffer, buflen)
+ end
+ buflen = buflen + 1
+ buffer[buflen] = "}"
+ end
+ tables[value] = nil
+ else
+ return exception ('unsupported type', value, state, buffer, buflen,
+ "type '" .. valtype .. "' is not supported by JSON.")
+ end
+ return buflen
+end
+
+function json.encode (value, state)
+ state = state or {}
+ local oldbuffer = state.buffer
+ local buffer = oldbuffer or {}
+ state.buffer = buffer
+ updatedecpoint()
+ local ret, msg = encode2 (value, state.indent, state.level or 0,
+ buffer, state.bufferlen or 0, state.tables or {}, state.keyorder, state)
+ if not ret then
+ error (msg, 2)
+ elseif oldbuffer == buffer then
+ state.bufferlen = ret
+ return true
+ else
+ state.bufferlen = nil
+ state.buffer = nil
+ return concat (buffer)
+ end
+end
+
+local function loc (str, where)
+ local line, pos, linepos = 1, 1, 0
+ while true do
+ pos = strfind (str, "\n", pos, true)
+ if pos and pos < where then
+ line = line + 1
+ linepos = pos
+ pos = pos + 1
+ else
+ break
+ end
+ end
+ return "line " .. line .. ", column " .. (where - linepos)
+end
+
+local function unterminated (str, what, where)
+ return nil, strlen (str) + 1, "unterminated " .. what .. " at " .. loc (str, where)
+end
+
+local function scanwhite (str, pos)
+ while true do
+ pos = strfind (str, "%S", pos)
+ if not pos then return nil end
+ local sub2 = strsub (str, pos, pos + 1)
+ if sub2 == "\239\187" and strsub (str, pos + 2, pos + 2) == "\191" then
+ -- UTF-8 Byte Order Mark
+ pos = pos + 3
+ elseif sub2 == "//" then
+ pos = strfind (str, "[\n\r]", pos + 2)
+ if not pos then return nil end
+ elseif sub2 == "/*" then
+ pos = strfind (str, "*/", pos + 2)
+ if not pos then return nil end
+ pos = pos + 2
+ else
+ return pos
+ end
+ end
+end
+
+local escapechars = {
+ ["\""] = "\"", ["\\"] = "\\", ["/"] = "/", ["b"] = "\b", ["f"] = "\f",
+ ["n"] = "\n", ["r"] = "\r", ["t"] = "\t"
+}
+
+local function unichar (value)
+ if value < 0 then
+ return nil
+ elseif value <= 0x007f then
+ return strchar (value)
+ elseif value <= 0x07ff then
+ return strchar (0xc0 + floor(value/0x40),
+ 0x80 + (floor(value) % 0x40))
+ elseif value <= 0xffff then
+ return strchar (0xe0 + floor(value/0x1000),
+ 0x80 + (floor(value/0x40) % 0x40),
+ 0x80 + (floor(value) % 0x40))
+ elseif value <= 0x10ffff then
+ return strchar (0xf0 + floor(value/0x40000),
+ 0x80 + (floor(value/0x1000) % 0x40),
+ 0x80 + (floor(value/0x40) % 0x40),
+ 0x80 + (floor(value) % 0x40))
+ else
+ return nil
+ end
+end
+
+local function scanstring (str, pos)
+ local lastpos = pos + 1
+ local buffer, n = {}, 0
+ while true do
+ local nextpos = strfind (str, "[\"\\]", lastpos)
+ if not nextpos then
+ return unterminated (str, "string", pos)
+ end
+ if nextpos > lastpos then
+ n = n + 1
+ buffer[n] = strsub (str, lastpos, nextpos - 1)
+ end
+ if strsub (str, nextpos, nextpos) == "\"" then
+ lastpos = nextpos + 1
+ break
+ else
+ local escchar = strsub (str, nextpos + 1, nextpos + 1)
+ local value
+ if escchar == "u" then
+ value = tonumber (strsub (str, nextpos + 2, nextpos + 5), 16)
+ if value then
+ local value2
+ if 0xD800 <= value and value <= 0xDBff then
+ -- we have the high surrogate of UTF-16. Check if there is a
+ -- low surrogate escaped nearby to combine them.
+ if strsub (str, nextpos + 6, nextpos + 7) == "\\u" then
+ value2 = tonumber (strsub (str, nextpos + 8, nextpos + 11), 16)
+ if value2 and 0xDC00 <= value2 and value2 <= 0xDFFF then
+ value = (value - 0xD800) * 0x400 + (value2 - 0xDC00) + 0x10000
+ else
+ value2 = nil -- in case it was out of range for a low surrogate
+ end
+ end
+ end
+ value = value and unichar (value)
+ if value then
+ if value2 then
+ lastpos = nextpos + 12
+ else
+ lastpos = nextpos + 6
+ end
+ end
+ end
+ end
+ if not value then
+ value = escapechars[escchar] or escchar
+ lastpos = nextpos + 2
+ end
+ n = n + 1
+ buffer[n] = value
+ end
+ end
+ if n == 1 then
+ return buffer[1], lastpos
+ elseif n > 1 then
+ return concat (buffer), lastpos
+ else
+ return "", lastpos
+ end
+end
+
+local scanvalue -- forward declaration
+
+local function scantable (what, closechar, str, startpos, nullval, objectmeta, arraymeta)
+ local len = strlen (str)
+ local tbl, n = {}, 0
+ local pos = startpos + 1
+ if what == 'object' then
+ setmetatable (tbl, objectmeta)
+ else
+ setmetatable (tbl, arraymeta)
+ end
+ while true do
+ pos = scanwhite (str, pos)
+ if not pos then return unterminated (str, what, startpos) end
+ local char = strsub (str, pos, pos)
+ if char == closechar then
+ return tbl, pos + 1
+ end
+ local val1, err
+ val1, pos, err = scanvalue (str, pos, nullval, objectmeta, arraymeta)
+ if err then return nil, pos, err end
+ pos = scanwhite (str, pos)
+ if not pos then return unterminated (str, what, startpos) end
+ char = strsub (str, pos, pos)
+ if char == ":" then
+ if val1 == nil then
+ return nil, pos, "cannot use nil as table index (at " .. loc (str, pos) .. ")"
+ end
+ pos = scanwhite (str, pos + 1)
+ if not pos then return unterminated (str, what, startpos) end
+ local val2
+ val2, pos, err = scanvalue (str, pos, nullval, objectmeta, arraymeta)
+ if err then return nil, pos, err end
+ tbl[val1] = val2
+ pos = scanwhite (str, pos)
+ if not pos then return unterminated (str, what, startpos) end
+ char = strsub (str, pos, pos)
+ else
+ n = n + 1
+ tbl[n] = val1
+ end
+ if char == "," then
+ pos = pos + 1
+ end
+ end
+end
+
+scanvalue = function (str, pos, nullval, objectmeta, arraymeta)
+ pos = pos or 1
+ pos = scanwhite (str, pos)
+ if not pos then
+ return nil, strlen (str) + 1, "no valid JSON value (reached the end)"
+ end
+ local char = strsub (str, pos, pos)
+ if char == "{" then
+ return scantable ('object', "}", str, pos, nullval, objectmeta, arraymeta)
+ elseif char == "[" then
+ return scantable ('array', "]", str, pos, nullval, objectmeta, arraymeta)
+ elseif char == "\"" then
+ return scanstring (str, pos)
+ else
+ local pstart, pend = strfind (str, "^%-?[%d%.]+[eE]?[%+%-]?%d*", pos)
+ if pstart then
+ local number = str2num (strsub (str, pstart, pend))
+ if number then
+ return number, pend + 1
+ end
+ end
+ pstart, pend = strfind (str, "^%a%w*", pos)
+ if pstart then
+ local name = strsub (str, pstart, pend)
+ if name == "true" then
+ return true, pend + 1
+ elseif name == "false" then
+ return false, pend + 1
+ elseif name == "null" then
+ return nullval, pend + 1
+ end
+ end
+ return nil, pos, "no valid JSON value at " .. loc (str, pos)
+ end
+end
+
+local function optionalmetatables(...)
+ if select("#", ...) > 0 then
+ return ...
+ else
+ return {__jsontype = 'object'}, {__jsontype = 'array'}
+ end
+end
+
+function json.decode (str, pos, nullval, ...)
+ local objectmeta, arraymeta = optionalmetatables(...)
+ return scanvalue (str, pos, nullval, objectmeta, arraymeta)
+end
+
+function json.use_lpeg ()
+ local g = require ("lpeg")
+
+ if g.version() == "0.11" then
+ error "due to a bug in LPeg 0.11, it cannot be used for JSON matching"
+ end
+
+ local pegmatch = g.match
+ local P, S, R = g.P, g.S, g.R
+
+ local function ErrorCall (str, pos, msg, state)
+ if not state.msg then
+ state.msg = msg .. " at " .. loc (str, pos)
+ state.pos = pos
+ end
+ return false
+ end
+
+ local function Err (msg)
+ return g.Cmt (g.Cc (msg) * g.Carg (2), ErrorCall)
+ end
+
+ local SingleLineComment = P"//" * (1 - S"\n\r")^0
+ local MultiLineComment = P"/*" * (1 - P"*/")^0 * P"*/"
+ local Space = (S" \n\r\t" + P"\239\187\191" + SingleLineComment + MultiLineComment)^0
+
+ local PlainChar = 1 - S"\"\\\n\r"
+ local EscapeSequence = (P"\\" * g.C (S"\"\\/bfnrt" + Err "unsupported escape sequence")) / escapechars
+ local HexDigit = R("09", "af", "AF")
+ local function UTF16Surrogate (match, pos, high, low)
+ high, low = tonumber (high, 16), tonumber (low, 16)
+ if 0xD800 <= high and high <= 0xDBff and 0xDC00 <= low and low <= 0xDFFF then
+ return true, unichar ((high - 0xD800) * 0x400 + (low - 0xDC00) + 0x10000)
+ else
+ return false
+ end
+ end
+ local function UTF16BMP (hex)
+ return unichar (tonumber (hex, 16))
+ end
+ local U16Sequence = (P"\\u" * g.C (HexDigit * HexDigit * HexDigit * HexDigit))
+ local UnicodeEscape = g.Cmt (U16Sequence * U16Sequence, UTF16Surrogate) + U16Sequence/UTF16BMP
+ local Char = UnicodeEscape + EscapeSequence + PlainChar
+ local String = P"\"" * g.Cs (Char ^ 0) * (P"\"" + Err "unterminated string")
+ local Integer = P"-"^(-1) * (P"0" + (R"19" * R"09"^0))
+ local Fractal = P"." * R"09"^0
+ local Exponent = (S"eE") * (S"+-")^(-1) * R"09"^1
+ local Number = (Integer * Fractal^(-1) * Exponent^(-1))/str2num
+ local Constant = P"true" * g.Cc (true) + P"false" * g.Cc (false) + P"null" * g.Carg (1)
+ local SimpleValue = Number + String + Constant
+ local ArrayContent, ObjectContent
+
+ -- The functions parsearray and parseobject parse only a single value/pair
+ -- at a time and store them directly to avoid hitting the LPeg limits.
+ local function parsearray (str, pos, nullval, state)
+ local obj, cont
+ local npos
+ local t, nt = {}, 0
+ repeat
+ obj, cont, npos = pegmatch (ArrayContent, str, pos, nullval, state)
+ if not npos then break end
+ pos = npos
+ nt = nt + 1
+ t[nt] = obj
+ until cont == 'last'
+ return pos, setmetatable (t, state.arraymeta)
+ end
+
+ local function parseobject (str, pos, nullval, state)
+ local obj, key, cont
+ local npos
+ local t = {}
+ repeat
+ key, obj, cont, npos = pegmatch (ObjectContent, str, pos, nullval, state)
+ if not npos then break end
+ pos = npos
+ t[key] = obj
+ until cont == 'last'
+ return pos, setmetatable (t, state.objectmeta)
+ end
+
+ local Array = P"[" * g.Cmt (g.Carg(1) * g.Carg(2), parsearray) * Space * (P"]" + Err "']' expected")
+ local Object = P"{" * g.Cmt (g.Carg(1) * g.Carg(2), parseobject) * Space * (P"}" + Err "'}' expected")
+ local Value = Space * (Array + Object + SimpleValue)
+ local ExpectedValue = Value + Space * Err "value expected"
+ ArrayContent = Value * Space * (P"," * g.Cc'cont' + g.Cc'last') * g.Cp()
+ local Pair = g.Cg (Space * String * Space * (P":" + Err "colon expected") * ExpectedValue)
+ ObjectContent = Pair * Space * (P"," * g.Cc'cont' + g.Cc'last') * g.Cp()
+ local DecodeValue = ExpectedValue * g.Cp ()
+
+ function json.decode (str, pos, nullval, ...)
+ local state = {}
+ state.objectmeta, state.arraymeta = optionalmetatables(...)
+ local obj, retpos = pegmatch (DecodeValue, str, pos, nullval, state)
+ if state.msg then
+ return nil, state.pos, state.msg
+ else
+ return obj, retpos
+ end
+ end
+
+ -- use this function only once:
+ json.use_lpeg = function () return json end
+
+ json.using_lpeg = true
+
+ return json -- so you can get the module using json = require "dkjson".use_lpeg()
+end
+
+if always_try_using_lpeg then
+ pcall (json.use_lpeg)
+end
+
+return json
+