Module:Jf-JSON

-- -*- coding: utf-8 -*- -- -- Simple JSON encoding and decoding in pure Lua. -- -- Copyright 2010-2016 Jeffrey Friedl -- http://regex.info/blog/ -- Latest version: http://regex.info/blog/lua/json -- -- This code is released under a Creative Commons CC-BY "Attribution" License: -- http://creativecommons.org/licenses/by/3.0/deed.en_US -- -- It can be used for any purpose so long as: --   1) the copyright notice above is maintained --    2) the web-page links above are maintained --   3) the 'AUTHOR_NOTE' string below is maintained -- local VERSION = '20161109.21' -- version history at end of file local AUTHOR_NOTE = "-[ JSON.lua package by Jeffrey Friedl (http://regex.info/blog/lua/json) version 20161109.21 ]-"

-- -- The 'AUTHOR_NOTE' variable exists so that information about the source -- of the package is maintained even in compiled versions. It's also -- included in OBJDEF below mostly to quiet warnings about unused variables. -- local OBJDEF = { VERSION     = VERSION, AUTHOR_NOTE = AUTHOR_NOTE, }

-- -- Simple JSON encoding and decoding in pure Lua. -- JSON definition: http://www.json.org/ -- -- --  JSON = assert(loadfile "JSON.lua") -- one-time load of the routines -- --  local lua_value = JSON:decode(raw_json_text) -- --  local raw_json_text    = JSON:encode(lua_table_or_value) --  local pretty_json_text = JSON:encode_pretty(lua_table_or_value) -- "pretty printed" version for human readability -- -- -- -- DECODING (from a JSON string to a Lua table) -- -- --  JSON = assert(loadfile "JSON.lua") -- one-time load of the routines -- --  local lua_value = JSON:decode(raw_json_text) -- --  If the JSON text is for an object or an array, e.g. --     { "what": "books", "count": 3 } --  or --     [ "Larry", "Curly", "Moe" ] -- --  the result is a Lua table, e.g. --     { what = "books", count = 3 } --  or --     { "Larry", "Curly", "Moe" } -- -- --  The encode and decode routines accept an optional second argument, --  "etc", which is not used during encoding or decoding, but upon error --  is passed along to error handlers. It can be of any type (including nil). -- -- -- -- ERROR HANDLING -- --  With most errors during decoding, this code calls -- --     JSON:onDecodeError(message, text, location, etc) -- --  with a message about the error, and if known, the JSON text being --  parsed and the byte count where the problem was discovered. You can --  replace the default JSON:onDecodeError with your own function. -- --  The default onDecodeError merely augments the message with data --  about the text and the location if known (and if a second 'etc' --   argument had been provided to decode, its value is tacked onto the --   message as well), and then calls JSON.assert, which itself defaults --  to Lua's built-in assert, and can also be overridden. -- --  For example, in an Adobe Lightroom plugin, you might use something like -- --         function JSON:onDecodeError(message, text, location, etc) --            LrErrors.throwUserError("Internal Error: invalid JSON data") --         end -- --  or even just -- --         function JSON.assert(message) --            LrErrors.throwUserError("Internal Error: " .. message) --         end -- --  If JSON:decode is passed a nil, this is called instead: -- --     JSON:onDecodeOfNilError(message, nil, nil, etc) -- --  and if JSON:decode is passed HTML instead of JSON, this is called: -- --     JSON:onDecodeOfHTMLError(message, text, nil, etc) -- --  The use of the fourth 'etc' argument allows stronger coordination --  between decoding and error reporting, especially when you provide your --  own error-handling routines. Continuing with the the Adobe Lightroom --  plugin example: -- --         function JSON:onDecodeError(message, text, location, etc) --            local note = "Internal Error: invalid JSON data" --            if type(etc) = 'table' and etc.photo then --               note = note .. " while processing for " .. etc.photo:getFormattedMetadata('fileName') --            end --            LrErrors.throwUserError(note) --         end -- --           : --            : -- --          for i, photo in ipairs(photosToProcess) do --               : --              :             --               local data = JSON:decode(someJsonText, { photo = photo }) --              :             --               :             --          end -- -- -- --  If the JSON text passed to decode has trailing garbage (e.g. as with the JSON "[123]xyzzy"), --  the method -- --      JSON:onTrailingGarbage(json_text, location, parsed_value, etc) -- --  is invoked, where: -- --      json_text is the original JSON text being parsed, --      location is the count of bytes into json_text where the garbage starts (6 in the example), --      parsed_value is the Lua result of what was successfully parsed ({123} in the example), --      etc is as above. -- --  If JSON:onTrailingGarbage does not abort, it should return the value decode should return, --  or nil + an error message. -- --    local new_value, error_message = JSON:onTrailingGarbage -- --  The default handler just invokes JSON:onDecodeError("trailing garbage"...), but you can have --  this package ignore trailing garbage via -- --     function JSON:onTrailingGarbage(json_text, location, parsed_value, etc) --        return parsed_value --     end -- -- -- DECODING AND STRICT TYPES -- --  Because both JSON objects and JSON arrays are converted to Lua tables, --  it's not normally possible to tell which original JSON type a --   particular Lua table was derived from, or guarantee decode-encode --  round-trip equivalency. -- --  However, if you enable strictTypes, e.g. -- --     JSON = assert(loadfile "JSON.lua") --load the routines --     JSON.strictTypes = true -- --  then the Lua table resulting from the decoding of a JSON object or --   JSON array is marked via Lua metatable, so that when re-encoded with --  JSON:encode it ends up as the appropriate JSON type. -- --  (This is not the default because other routines may not work well with --   tables that have a metatable set, for example, Lightroom API calls.) -- -- -- ENCODING (from a lua table to a JSON string) -- --  JSON = assert(loadfile "JSON.lua") -- one-time load of the routines -- --  local raw_json_text    = JSON:encode(lua_table_or_value) --  local pretty_json_text = JSON:encode_pretty(lua_table_or_value) -- "pretty printed" version for human readability --  local custom_pretty    = JSON:encode(lua_table_or_value, etc, { pretty = true, indent = "|  ", align_keys = false }) -- --  On error during encoding, this code calls: -- --    JSON:onEncodeError(message, etc) -- --  which you can override in your local JSON object. -- --  The 'etc' in the error call is the second argument to encode --  and encode_pretty, or nil if it wasn't provided. -- -- -- ENCODING OPTIONS -- --  An optional third argument, a table of options, can be provided to encode. -- --      encode_options =  { --          -- options for making "pretty" human-readable JSON (see "PRETTY-PRINTING" below) --          pretty         = true, --          indent         = "   ", --          align_keys     = false, -- --           -- other output-related options --          null           = "\0",   -- see "ENCODING JSON NULL VALUES" below --          stringsAreUtf8 = false,  -- see "HANDLING UNICODE LINE AND PARAGRAPH SEPARATORS FOR JAVA" below --      } --  --       json_string = JSON:encode(mytable, etc, encode_options) -- -- -- -- For reference, the defaults are: -- --          pretty         = false --          null           = nil, --          stringsAreUtf8 = false, -- -- -- -- PRETTY-PRINTING -- --  Enabling the 'pretty' encode option helps generate human-readable JSON. -- --    pretty = JSON:encode(val, etc, { --                                       pretty = true, --                                       indent = "   ", --                                       align_keys = false, --                                     }) -- --  encode_pretty is also provided: it's identical to encode except --  that encode_pretty provides a default options table if none given in the call: -- --      { pretty = true, align_keys = false, indent = "  " } -- --  For example, if -- --     JSON:encode(data) -- --  produces: -- --     {"city":"Kyoto","climate":{"avg_temp":16,"humidity":"high","snowfall":"minimal"},"country":"Japan","wards":11} -- --  then -- --     JSON:encode_pretty(data) -- --  produces: -- --     { --        "city": "Kyoto", --       "climate": { --         "avg_temp": 16, --         "humidity": "high", --         "snowfall": "minimal" --       }, --        "country": "Japan", --       "wards": 11 --     } -- --   The following three lines return identical results: --      JSON:encode_pretty(data) --      JSON:encode_pretty(data, nil, { pretty = true, align_keys = false, indent = "  " }) --      JSON:encode       (data, nil, { pretty = true, align_keys = false, indent = "  " }) -- --  An example of setting your own indent string: -- --    JSON:encode_pretty(data, nil, { pretty = true, indent = "|    " }) -- --  produces: -- --     { --      |    "city": "Kyoto", --     |    "climate": { --     |    |    "avg_temp": 16, --     |    |    "humidity": "high", --     |    |    "snowfall": "minimal" --     |    }, --      |    "country": "Japan", --     |    "wards": 11 --     } -- --   An example of setting align_keys to true: -- --    JSON:encode_pretty(data, nil, { pretty = true, indent = "  ", align_keys = true }) -- --   produces: --  --      { --           "city": "Kyoto", --       "climate": { --                    "avg_temp": 16, --                    "humidity": "high", --                    "snowfall": "minimal" --                  }, --        "country": "Japan", --         "wards": 11 --     } -- --   which I must admit is kinda ugly, sorry. This was the default for --  encode_pretty prior to version 20141223.14. -- -- -- HANDLING UNICODE LINE AND PARAGRAPH SEPARATORS FOR JAVA -- --   If the 'stringsAreUtf8' encode option is set to true, consider Lua strings not as a sequence of bytes, --   but as a sequence of UTF-8 characters. -- --   Currently, the only practical effect of setting this option is that Unicode LINE and PARAGRAPH --   separators, if found in a string, are encoded with a JSON escape instead of being dumped as is. --   The JSON is valid either way, but encoding this way, apparently, allows the resulting JSON --   to also be valid Java. -- -- AMBIGUOUS SITUATIONS DURING THE ENCODING -- --  During the encode, if a Lua table being encoded contains both string --  and numeric keys, it fits neither JSON's idea of an object, nor its --  idea of an array. To get around this, when any string key exists (or --  when non-positive numeric keys exist), numeric keys are converted to --   strings. -- --  For example, --    JSON:encode({ "one", "two", "three", SOMESTRING = "some string" })) --   produces the JSON object --     {"1":"one","2":"two","3":"three","SOMESTRING":"some string"} -- --   To prohibit this conversion and instead make it an error condition, set --      JSON.noKeyConversion = true -- -- -- ENCODING JSON NULL VALUES -- --   Lua tables completely omit keys whose value is nil, so without special handling there's --   no way to get a field in a JSON object with a null value.  For example --      JSON:encode({ username = "admin", password = nil }) --   produces --      {"username":"admin"} -- --   In order to actually produce --      {"username":"admin", "password":null} --   one can include a string value for a "null" field in the options table passed to encode.... --   any Lua table entry with that value becomes null in the JSON output: --      JSON:encode({ username = "admin", password = "xyzzy" }, nil, { null = "xyzzy" }) --  produces --     {"username":"admin", "password":null} -- --  Just be sure to use a string that is otherwise unlikely to appear in your data. --  The string "\0" (a string with one null byte) may well be appropriate for many applications. -- --  The "null" options also applies to Lua tables that become JSON arrays. --     JSON:encode({ "one", "two", nil, nil }) --  produces --     ["one","two"] --  while --     NULL = "\0" --     JSON:encode({ "one", "two", NULL, NULL}, nil, { null = NULL }) --  produces --     ["one","two",null,null] -- -- -- -- -- HANDLING LARGE AND/OR PRECISE NUMBERS -- -- --  Without special handling, numbers in JSON can lose precision in Lua. --  For example: --  --      T = JSON:decode('{  "small":12345, "big":12345678901234567890123456789, "precise":9876.67890123456789012345  }') -- --     print("small:   ",  type(T.small),    T.small) --     print("big:     ",  type(T.big),      T.big) --     print("precise: ",  type(T.precise),  T.precise) --  --   produces --  --      small:          number  12345 --     big:            number  1.2345678901235e+28 --     precise:        number  9876.6789012346 -- --  Precision is lost with both 'big' and 'precise'. -- --  This package offers ways to try to handle this better (for some definitions of "better")... -- --  The most precise method is by setting the global: --  --      JSON.decodeNumbersAsObjects = true --  --   When this is set, numeric JSON data is encoded into Lua in a form that preserves the exact --  JSON numeric presentation when re-encoded back out to JSON, or accessed in Lua as a string. -- --  (This is done by encoding the numeric data with a Lua table/metatable that returns --   the possibly-imprecise numeric form when accessed numerically, but the original precise --   representation when accessed as a string. You can also explicitly access --   via JSON:forceString and JSON:forceNumber) -- --  Consider the example above, with this option turned on: -- --     JSON.decodeNumbersAsObjects = true --     --      T = JSON:decode('{  "small":12345, "big":12345678901234567890123456789, "precise":9876.67890123456789012345  }') -- --     print("small:   ",  type(T.small),    T.small) --     print("big:     ",  type(T.big),      T.big) --     print("precise: ",  type(T.precise),  T.precise) --  --   This now produces: --  --      small:          table   12345 --     big:            table   12345678901234567890123456789 --     precise:        table   9876.67890123456789012345 --  --   However, within Lua you can still use the values (e.g. T.precise in the example above) in numeric --  contexts. In such cases you'll get the possibly-imprecise numeric version, but in string contexts --  and when the data finds its way to this package's encode function, the original full-precision --  representation is used. -- --  Even without using the JSON.decodeNumbersAsObjects option, you can encode numbers --  in your Lua table that retain high precision upon encoding to JSON, by using the JSON:asNumber --  function: -- --     T = { --        imprecise = 123456789123456789.123456789123456789, --        precise   = JSON:asNumber("123456789123456789.123456789123456789") --     } -- --      print(JSON:encode_pretty(T)) -- --  This produces: -- --     { --         "precise": 123456789123456789.123456789123456789, --        "imprecise": 1.2345678912346e+17 --     } -- -- -- --   A different way to handle big/precise JSON numbers is to have decode merely return --  the exact string representation of the number instead of the number itself. --  This approach might be useful when the numbers are merely some kind of opaque --  object identifier and you want to work with them in Lua as strings anyway. --  --   This approach is enabled by setting -- --     JSON.decodeIntegerStringificationLength = 10 -- --  The value is the number of digits (of the integer part of the number) at which to stringify numbers. -- --  Consider our previous example with this option set to 10: -- --     JSON.decodeIntegerStringificationLength = 10 --     --      T = JSON:decode('{  "small":12345, "big":12345678901234567890123456789, "precise":9876.67890123456789012345  }') -- --     print("small:   ",  type(T.small),    T.small) --     print("big:     ",  type(T.big),      T.big) --     print("precise: ",  type(T.precise),  T.precise) -- --  This produces: -- --     small:          number  12345 --     big:            string  12345678901234567890123456789 --     precise:        number  9876.6789012346 -- --  The long integer of the 'big' field is at least JSON.decodeIntegerStringificationLength digits --  in length, so it's converted not to a Lua integer but to a Lua string. Using a value of 0 or 1 ensures --  that all JSON numeric data becomes strings in Lua. -- --  Note that unlike --     JSON.decodeNumbersAsObjects = true --  this stringification is simple and unintelligent: the JSON number simply becomes a Lua string, and that's the end of it. --  If the string is then converted back to JSON, it's still a string. After running the code above, adding --     print(JSON:encode(T)) --  produces --     {"big":"12345678901234567890123456789","precise":9876.6789012346,"small":12345} --  which is unlikely to be desired. -- --  There's a comparable option for the length of the decimal part of a number: -- --     JSON.decodeDecimalStringificationLength -- --  This can be used alone or in conjunction with -- --     JSON.decodeIntegerStringificationLength -- --  to trip stringification on precise numbers with at least JSON.decodeIntegerStringificationLength digits after --  the decimal point. -- --  This example: -- --     JSON.decodeIntegerStringificationLength = 10 --     JSON.decodeDecimalStringificationLength =  5 -- --     T = JSON:decode('{  "small":12345, "big":12345678901234567890123456789, "precise":9876.67890123456789012345  }') --     --      print("small:   ",  type(T.small),    T.small) --     print("big:     ",  type(T.big),      T.big) --     print("precise: ",  type(T.precise),  T.precise) -- -- produces: -- --     small:          number  12345 --     big:            string  12345678901234567890123456789 --     precise:        string  9876.67890123456789012345 -- -- -- -- -- -- SUMMARY OF METHODS YOU CAN OVERRIDE IN YOUR LOCAL LUA JSON OBJECT -- --   assert --   onDecodeError --   onDecodeOfNilError --   onDecodeOfHTMLError --   onTrailingGarbage --   onEncodeError -- -- If you want to create a separate Lua JSON object with its own error handlers, -- you can reload JSON.lua or use the :new method. -- ---

local default_pretty_indent = "  " local default_pretty_options = { pretty = true, align_keys = false, indent = default_pretty_indent }

local isArray = { __tostring = function return "JSON array"         end }  isArray.__index  = isArray local isObject = { __tostring = function return "JSON object"       end }  isObject.__index = isObject

function OBJDEF:newArray(tbl) return setmetatable(tbl or {}, isArray) end

function OBJDEF:newObject(tbl) return setmetatable(tbl or {}, isObject) end

local function getnum(op) return type(op) == 'number' and op or op.N end

local isNumber = { __tostring = function(T) return T.S        end, __unm     = function(op) return getnum(op) end,

__concat  = function(op1, op2) return tostring(op1) .. tostring(op2) end, __add     = function(op1, op2) return getnum(op1)   +   getnum(op2)  end, __sub     = function(op1, op2) return getnum(op1)   -   getnum(op2)  end, __mul     = function(op1, op2) return getnum(op1)   *   getnum(op2)  end, __div     = function(op1, op2) return getnum(op1)   /   getnum(op2)  end, __mod     = function(op1, op2) return getnum(op1)   %   getnum(op2)  end, __pow     = function(op1, op2) return getnum(op1)   ^   getnum(op2)  end, __lt      = function(op1, op2) return getnum(op1)   <   getnum(op2)  end, __eq      = function(op1, op2) return getnum(op1)   ==  getnum(op2)  end, __le      = function(op1, op2) return getnum(op1)   <=  getnum(op2)  end, } isNumber.__index = isNumber

function OBJDEF:asNumber(item)

if getmetatable(item) == isNumber then -- it's already a JSON number object. return item elseif type(item) == 'table' and type(item.S) == 'string' and type(item.N) == 'number' then -- it's a number-object table that lost its metatable, so give it one return setmetatable(item, isNumber) else -- the normal situation... given a number or a string representation of a number.... local holder = { S = tostring(item), -- S is the representation of the number as a string, which remains precise N = tonumber(item), -- N is the number as a Lua number. }     return setmetatable(holder, isNumber) end end

-- -- Given an item that might be a normal string or number, or might be an 'isNumber' object defined above, -- return the string version. This shouldn't be needed often because the 'isNumber' object should autoconvert -- to a string in most cases, but it's here to allow it to be forced when needed. -- function OBJDEF:forceString(item) if type(item) == 'table' and type(item.S) == 'string' then return item.S  else return tostring(item) end end

-- -- Given an item that might be a normal string or number, or might be an 'isNumber' object defined above, -- return the numeric version. -- function OBJDEF:forceNumber(item) if type(item) == 'table' and type(item.N) == 'number' then return item.N  else return tonumber(item) end end

local function unicode_codepoint_as_utf8(codepoint) --  -- codepoint is a number --  if codepoint <= 127 then return string.char(codepoint)

elseif codepoint <= 2047 then --     -- 110yyyxx 10xxxxxx         <-- useful notation from http://en.famepedia.org/wiki/Utf8 --     local highpart = math.floor(codepoint / 0x40) local lowpart = codepoint - (0x40 * highpart) return string.char(0xC0 + highpart,                        0x80 + lowpart)

elseif codepoint <= 65535 then --     -- 1110yyyy 10yyyyxx 10xxxxxx --     local highpart  = math.floor(codepoint / 0x1000) local remainder = codepoint - 0x1000 * highpart local midpart  = math.floor(remainder / 0x40) local lowpart  = remainder - 0x40 * midpart

highpart = 0xE0 + highpart midpart = 0x80 + midpart lowpart = 0x80 + lowpart

--     -- Check for an invalid character (thanks Andy R. at Adobe). -- See table 3.7, page 93, in http://www.unicode.org/versions/Unicode5.2.0/ch03.pdf#G28070 --     if ( highpart == 0xE0 and midpart < 0xA0 ) or         ( highpart == 0xED and midpart > 0x9F ) or         ( highpart == 0xF0 and midpart < 0x90 ) or         ( highpart == 0xF4 and midpart > 0x8F ) then return "?" else return string.char(highpart,                           midpart,                            lowpart) end

else --     -- 11110zzz 10zzyyyy 10yyyyxx 10xxxxxx --     local highpart  = math.floor(codepoint / 0x40000) local remainder = codepoint - 0x40000 * highpart local midA     = math.floor(remainder / 0x1000) remainder      = remainder - 0x1000 * midA local midB     = math.floor(remainder / 0x40) local lowpart  = remainder - 0x40 * midB

return string.char(0xF0 + highpart,                        0x80 + midA,                         0x80 + midB,                         0x80 + lowpart) end end

function OBJDEF:onDecodeError(message, text, location, etc) if text then if location then message = string.format("%s at byte %d of: %s", message, location, text) else message = string.format("%s: %s", message, text) end end

if etc ~= nil then message = message .. " (" .. OBJDEF:encode(etc) .. ")" end

if self.assert then self.assert(false, message) else assert(false, message) end end

function OBJDEF:onTrailingGarbage(json_text, location, parsed_value, etc) return self:onDecodeError("trailing garbage", json_text, location, etc) end

OBJDEF.onDecodeOfNilError = OBJDEF.onDecodeError OBJDEF.onDecodeOfHTMLError = OBJDEF.onDecodeError

function OBJDEF:onEncodeError(message, etc) if etc ~= nil then message = message .. " (" .. OBJDEF:encode(etc) .. ")" end

if self.assert then self.assert(false, message) else assert(false, message) end end

local function grok_number(self, text, start, options) --  -- Grab the integer part --  local integer_part = text:match('^-?[1-9]%d*', start) or text:match("^-?0",       start)

if not integer_part then self:onDecodeError("expected number", text, start, options.etc) return nil, start -- in case the error method doesn't abort, return something sensible end

local i = start + integer_part:len

--  -- Grab an optional decimal part --  local decimal_part = text:match('^%.%d+', i) or ""

i = i + decimal_part:len

--  -- Grab an optional exponential part --  local exponent_part = text:match('^[eE][-+]?%d+', i) or ""

i = i + exponent_part:len

local full_number_text = integer_part .. decimal_part .. exponent_part

if options.decodeNumbersAsObjects then return OBJDEF:asNumber(full_number_text), i  end

--  -- If we're told to stringify under certain conditions, so do. -- We punt a bit when there's an exponent by just stringifying no matter what. -- I suppose we should really look to see whether the exponent is actually big enough one -- way or the other to trip stringification, but I'll be lazy about it until someone asks. --  if (options.decodeIntegerStringificationLength       and      (integer_part:len >= options.decodeIntegerStringificationLength or exponent_part:len > 0))

or

(options.decodeDecimalStringificationLength       and       (decimal_part:len >= options.decodeDecimalStringificationLength or exponent_part:len > 0)) then return full_number_text, i -- this returns the exact string representation seen in the original JSON end

local as_number = tonumber(full_number_text)

if not as_number then self:onDecodeError("bad number", text, start, options.etc) return nil, start -- in case the error method doesn't abort, return something sensible end

return as_number, i end

local function grok_string(self, text, start, options)

if text:sub(start,start) ~= '"' then     self:onDecodeError("expected string's opening quote", text, start, options.etc)      return nil, start -- in case the error method doesn't abort, return something sensible   end

local i = start + 1 -- +1 to bypass the initial quote local text_len = text:len local VALUE = "" while i <= text_len do     local c = text:sub(i,i) if c == '"' then        return VALUE, i + 1      end      if c ~= '\\' then         VALUE = VALUE .. c         i = i + 1      elseif text:match('^\\b', i) then         VALUE = VALUE .. "\b"         i = i + 2      elseif text:match('^\\f', i) then         VALUE = VALUE .. "\f"         i = i + 2      elseif text:match('^\\n', i) then         VALUE = VALUE .. "\n"         i = i + 2      elseif text:match('^\\r', i) then         VALUE = VALUE .. "\r"         i = i + 2      elseif text:match('^\\t', i) then         VALUE = VALUE .. "\t"         i = i + 2      else         local hex = text:match('^\\u([0123456789aAbBcCdDeEfF][0123456789aAbBcCdDeEfF][0123456789aAbBcCdDeEfF][0123456789aAbBcCdDeEfF])', i)         if hex then            i = i + 6 -- bypass what we just read

-- We have a Unicode codepoint. It could be standalone, or if in the proper range and -- followed by another in a specific range, it'll be a two-code surrogate pair. local codepoint = tonumber(hex, 16) if codepoint >= 0xD800 and codepoint <= 0xDBFF then -- it's a hi surrogate... see whether we have a following low local lo_surrogate = text:match('^\\u([dD][cdefCDEF][0123456789aAbBcCdDeEfF][0123456789aAbBcCdDeEfF])', i)              if lo_surrogate then i = i + 6 -- bypass the low surrogate we just read codepoint = 0x2400 + (codepoint - 0xD800) * 0x400 + tonumber(lo_surrogate, 16) else -- not a proper low, so we'll just leave the first codepoint as is and spit it out. end end VALUE = VALUE .. unicode_codepoint_as_utf8(codepoint)

else

-- just pass through what's escaped VALUE = VALUE .. text:match('^\\(.)', i)           i = i + 2 end end end

self:onDecodeError("unclosed string", text, start, options.etc) return nil, start -- in case the error method doesn't abort, return something sensible end

local function skip_whitespace(text, start)

local _, match_end = text:find("^[ \n\r\t]+", start) -- Section 2 if match_end then return match_end + 1 else return start end end

local grok_one -- assigned later

local function grok_object(self, text, start, options)

if text:sub(start,start) ~= '{' then self:onDecodeError("expected '{'", text, start, options.etc) return nil, start -- in case the error method doesn't abort, return something sensible end

local i = skip_whitespace(text, start + 1) -- +1 to skip the '{'

local VALUE = self.strictTypes and self:newObject { } or { }

if text:sub(i,i) == '}' then return VALUE, i + 1 end local text_len = text:len while i <= text_len do     local key, new_i = grok_string(self, text, i, options)

i = skip_whitespace(text, new_i)

if text:sub(i, i) ~= ':' then self:onDecodeError("expected colon", text, i, options.etc) return nil, i -- in case the error method doesn't abort, return something sensible end

i = skip_whitespace(text, i + 1)

local new_val, new_i = grok_one(self, text, i, options)

VALUE[key] = new_val

--     -- Expect now either '}' to end things, or a ',' to allow us to continue. --     i = skip_whitespace(text, new_i)

local c = text:sub(i,i)

if c == '}' then return VALUE, i + 1 end

if text:sub(i, i) ~= ',' then self:onDecodeError("expected comma or '}'", text, i, options.etc) return nil, i -- in case the error method doesn't abort, return something sensible end

i = skip_whitespace(text, i + 1) end

self:onDecodeError("unclosed '{'", text, start, options.etc) return nil, start -- in case the error method doesn't abort, return something sensible end

local function grok_array(self, text, start, options) if text:sub(start,start) ~= '[' then self:onDecodeError("expected '['", text, start, options.etc) return nil, start -- in case the error method doesn't abort, return something sensible end

local i = skip_whitespace(text, start + 1) -- +1 to skip the '[' local VALUE = self.strictTypes and self:newArray { } or { } if text:sub(i,i) == ']' then return VALUE, i + 1 end

local VALUE_INDEX = 1

local text_len = text:len while i <= text_len do     local val, new_i = grok_one(self, text, i, options)

-- can't table.insert(VALUE, val) here because it's a no-op if val is nil VALUE[VALUE_INDEX] = val VALUE_INDEX = VALUE_INDEX + 1

i = skip_whitespace(text, new_i)

--     -- Expect now either ']' to end things, or a ',' to allow us to continue. --     local c = text:sub(i,i) if c == ']' then return VALUE, i + 1 end if text:sub(i, i) ~= ',' then self:onDecodeError("expected comma or ']'", text, i, options.etc) return nil, i -- in case the error method doesn't abort, return something sensible end i = skip_whitespace(text, i + 1) end self:onDecodeError("unclosed '['", text, start, options.etc) return nil, i -- in case the error method doesn't abort, return something sensible end

grok_one = function(self, text, start, options) -- Skip any whitespace start = skip_whitespace(text, start)

if start > text:len then self:onDecodeError("unexpected end of string", text, nil, options.etc) return nil, start -- in case the error method doesn't abort, return something sensible end

if text:find('^"', start) then     return grok_string(self, text, start, options.etc)

elseif text:find('^[-0123456789 ]', start) then return grok_number(self, text, start, options)

elseif text:find('^%{', start) then return grok_object(self, text, start, options)

elseif text:find('^%[', start) then return grok_array(self, text, start, options)

elseif text:find('^true', start) then return true, start + 4

elseif text:find('^false', start) then return false, start + 5

elseif text:find('^null', start) then return nil, start + 4

else self:onDecodeError("can't parse JSON", text, start, options.etc) return nil, 1 -- in case the error method doesn't abort, return something sensible end end

function OBJDEF:decode(text, etc, options) --  -- If the user didn't pass in a table of decode options, make an empty one. --  if type(options) ~= 'table' then options = {} end

--  -- If they passed in an 'etc' argument, stuff it into the options. -- (If not, any 'etc' field in the options they passed in remains to be used) --  if etc ~= nil then options.etc = etc end

if type(self) ~= 'table' or self.__index ~= OBJDEF then local error_message = "JSON:decode must be called in method format" OBJDEF:onDecodeError(error_message, nil, nil, options.etc) return nil, error_message -- in case the error method doesn't abort, return something sensible end

if text == nil then local error_message = "nil passed to JSON:decode" self:onDecodeOfNilError(error_message, nil, nil, options.etc) return nil, error_message -- in case the error method doesn't abort, return something sensible

elseif type(text) ~= 'string' then local error_message = "expected string argument to JSON:decode" self:onDecodeError(string.format("%s, got %s", error_message, type(text)), nil, nil, options.etc) return nil, error_message -- in case the error method doesn't abort, return something sensible end

if text:match('^%s*$') then -- an empty string is nothing, but not an error return nil end

if text:match('^%s*<') then -- Can't be JSON... we'll assume it's HTML local error_message = "HTML passed to JSON:decode" self:onDecodeOfHTMLError(error_message, text, nil, options.etc) return nil, error_message -- in case the error method doesn't abort, return something sensible end

--  -- Ensure that it's not UTF-32 or UTF-16. -- Those are perfectly valid encodings for JSON (as per RFC 4627 section 3), -- but this package can't handle them. --  if text:sub(1,1):byte == 0 or (text:len >= 2 and text:sub(2,2):byte == 0) then local error_message = "JSON package groks only UTF-8, sorry" self:onDecodeError(error_message, text, nil, options.etc) return nil, error_message -- in case the error method doesn't abort, return something sensible end

--  -- apply global options --  if options.decodeNumbersAsObjects == nil then options.decodeNumbersAsObjects = self.decodeNumbersAsObjects end if options.decodeIntegerStringificationLength == nil then options.decodeIntegerStringificationLength = self.decodeIntegerStringificationLength end if options.decodeDecimalStringificationLength == nil then options.decodeDecimalStringificationLength = self.decodeDecimalStringificationLength end

--  -- Finally, go parse it   -- local success, value, next_i = pcall(grok_one, self, text, 1, options)

if success then

local error_message = nil if next_i ~= #text + 1 then -- something's left over after we parsed the first thing.... whitespace is allowed. next_i = skip_whitespace(text, next_i)

-- if we have something left over now, it's trailing garbage if next_i ~= #text + 1 then value, error_message = self:onTrailingGarbage(text, next_i, value, options.etc) end end return value, error_message

else

-- If JSON:onDecodeError didn't abort out of the pcall, we'll have received -- the error message here as "value", so pass it along as an assert. local error_message = value if self.assert then self.assert(false, error_message) else assert(false, error_message) end -- ...and if we're still here (because the assert didn't throw an error), -- return a nil and throw the error message on as a second arg return nil, error_message

end end

local function backslash_replacement_function(c) if c == "\n" then return "\\n" elseif c == "\r" then return "\\r" elseif c == "\t" then return "\\t" elseif c == "\b" then return "\\b" elseif c == "\f" then return "\\f" elseif c == '"' then     return '\\"' elseif c == '\\' then return '\\\\' else return string.format("\\u%04x", c:byte) end end

local chars_to_be_escaped_in_JSON_string = '['  ..    '"'    -- class sub-pattern to match a double quote   ..    '%\\'  -- class sub-pattern to match a backslash   ..    '%z'   -- class sub-pattern to match a null   ..    '\001' .. '-' .. '\031' -- class sub-pattern to match control characters   .. ']'

local LINE_SEPARATOR_as_utf8     = unicode_codepoint_as_utf8(0x2028) local PARAGRAPH_SEPARATOR_as_utf8 = unicode_codepoint_as_utf8(0x2029) local function json_string_literal(value, options) local newval = value:gsub(chars_to_be_escaped_in_JSON_string, backslash_replacement_function) if options.stringsAreUtf8 then --     -- This feels really ugly to just look into a string for the sequence of bytes that we know to be a particular utf8 character, -- but utf8 was designed purposefully to make this kind of thing possible. Still, feels dirty. -- I'd rather decode the byte stream into a character stream, but it's not technically needed so     -- not technically worth it. --     newval = newval:gsub(LINE_SEPARATOR_as_utf8, '\\u2028'):gsub(PARAGRAPH_SEPARATOR_as_utf8,'\\u2029') end return '"' .. newval .. '"' end

local function object_or_array(self, T, etc) --  -- We need to inspect all the keys... if there are any strings, we'll convert to a JSON -- object. If there are only numbers, it's a JSON array. --  -- If we'll be converting to a JSON object, we'll want to sort the keys so that the -- end result is deterministic. --  local string_keys = { } local number_keys = { } local number_keys_must_be_strings = false local maximum_number_key

for key in pairs(T) do     if type(key) == 'string' then table.insert(string_keys, key) elseif type(key) == 'number' then table.insert(number_keys, key) if key <= 0 or key >= math.huge then number_keys_must_be_strings = true elseif not maximum_number_key or key > maximum_number_key then maximum_number_key = key end else self:onEncodeError("can't encode table with a key of type " .. type(key), etc) end end

if #string_keys == 0 and not number_keys_must_be_strings then --     -- An empty table, or a numeric-only array --     if #number_keys > 0 then return nil, maximum_number_key -- an array elseif tostring(T) == "JSON array" then return nil elseif tostring(T) == "JSON object" then return { } else -- have to guess, so we'll pick array, since empty arrays are likely more common than empty objects return nil end end

table.sort(string_keys)

local map if #number_keys > 0 then --     -- If we're here then we have either mixed string/number keys, or numbers inappropriate for a JSON array -- It's not ideal, but we'll turn the numbers into strings so that we can at least create a JSON object. --

if self.noKeyConversion then self:onEncodeError("a table with both numeric and string keys could be an object or array; aborting", etc) end

--     -- Have to make a shallow copy of the source table so we can remap the numeric keys to be strings --     map = { } for key, val in pairs(T) do        map[key] = val end

table.sort(number_keys)

--     -- Throw numeric keys in there as strings --     for _, number_key in ipairs(number_keys) do         local string_key = tostring(number_key) if map[string_key] == nil then table.insert(string_keys, string_key) map[string_key] = T[number_key] else self:onEncodeError("conflict converting table with mixed-type keys into a JSON object: key " .. number_key .. " exists both as a string and a number.", etc) end end end

return string_keys, nil, map end

-- -- Encode -- -- 'options' is nil, or a table with possible keys: -- --   pretty         -- If true, return a pretty-printed version. -- --   indent         -- A string (usually of spaces) used to indent each nested level. -- --   align_keys     -- If true, align all the keys when formatting a table. -- --   null           -- If this exists with a string value, table elements with this value are output as JSON null. -- --   stringsAreUtf8 -- If true, consider Lua strings not as a sequence of bytes, but as a sequence of UTF-8 characters. --                     (Currently, the only practical effect of setting this option is that Unicode LINE and PARAGRAPH --                       separators, if found in a string, are encoded with a JSON escape instead of as raw UTF-8. --                       The JSON is valid either way, but encoding this way, apparently, allows the resulting JSON --                       to also be valid Java.) -- -- local encode_value -- must predeclare because it calls itself function encode_value(self, value, parents, etc, options, indent, for_key)

--  -- keys in a JSON object can never be null, so we don't even consider options.null when converting a key value --  if value == nil or (not for_key and options and options.null and value == options.null) then return 'null'

elseif type(value) == 'string' then return json_string_literal(value, options)

elseif type(value) == 'number' then if value ~= value then --        -- NaN (Not a Number). -- JSON has no NaN, so we have to fudge the best we can. This should really be a package option. --        return "null" elseif value >= math.huge then --        -- Positive infinity. JSON has no INF, so we have to fudge the best we can. This should -- really be a package option. Note: at least with some implementations, positive infinity -- is both ">= math.huge" and "<= -math.huge", which makes no sense but that's how it is. -- Negative infinity is properly "<= -math.huge". So, we must be sure to check the ">=" -- case first. --        return "1e+9999" elseif value <= -math.huge then --        -- Negative infinity. -- JSON has no INF, so we have to fudge the best we can. This should really be a package option. --        return "-1e+9999" else return tostring(value) end

elseif type(value) == 'boolean' then return tostring(value)

elseif type(value) ~= 'table' then self:onEncodeError("can't convert " .. type(value) .. " to JSON", etc)

elseif getmetatable(value) == isNumber then return tostring(value) else --     -- A table to be converted to either a JSON object or array. --     local T = value

if type(options) ~= 'table' then options = {} end if type(indent) ~= 'string' then indent = "" end

if parents[T] then self:onEncodeError("table " .. tostring(T) .. " is a child of itself", etc) else parents[T] = true end

local result_value

local object_keys, maximum_number_key, map = object_or_array(self, T, etc) if maximum_number_key then --        -- An array... --        local ITEMS = { } for i = 1, maximum_number_key do           table.insert(ITEMS, encode_value(self, T[i], parents, etc, options, indent)) end

if options.pretty then result_value = "[ " .. table.concat(ITEMS, ", ") .. " ]"        else result_value = "[" .. table.concat(ITEMS, ",") .. "]"        end

elseif object_keys then --        -- An object --        local TT = map or T

if options.pretty then

local KEYS = { } local max_key_length = 0 for _, key in ipairs(object_keys) do              local encoded = encode_value(self, tostring(key), parents, etc, options, indent, true) if options.align_keys then max_key_length = math.max(max_key_length, #encoded) end table.insert(KEYS, encoded) end local key_indent = indent .. tostring(options.indent or "") local subtable_indent = key_indent .. string.rep(" ", max_key_length) .. (options.align_keys and " " or "") local FORMAT = "%s%" .. string.format("%d", max_key_length) .. "s: %s"

local COMBINED_PARTS = { } for i, key in ipairs(object_keys) do              local encoded_val = encode_value(self, TT[key], parents, etc, options, subtable_indent) table.insert(COMBINED_PARTS, string.format(FORMAT, key_indent, KEYS[i], encoded_val)) end result_value = "{\n" .. table.concat(COMBINED_PARTS, ",\n") .. "\n" .. indent .. "}"

else

local PARTS = { } for _, key in ipairs(object_keys) do              local encoded_val = encode_value(self, TT[key],       parents, etc, options, indent) local encoded_key = encode_value(self, tostring(key), parents, etc, options, indent, true) table.insert(PARTS, string.format("%s:%s", encoded_key, encoded_val)) end result_value = "{" .. table.concat(PARTS, ",") .. "}"

end else --        -- An empty array/object... we'll treat it as an array, though it should really be an option --        result_value = "[]" end

parents[T] = false return result_value end end

local function top_level_encode(self, value, etc, options) local val = encode_value(self, value, {}, etc, options) if val == nil then --PRIVATE("may need to revert to the previous public verison if I can't figure out what the guy wanted") return val else return val end end

function OBJDEF:encode(value, etc, options) if type(self) ~= 'table' or self.__index ~= OBJDEF then OBJDEF:onEncodeError("JSON:encode must be called in method format", etc) end

--  -- If the user didn't pass in a table of decode options, make an empty one. --  if type(options) ~= 'table' then options = {} end

return top_level_encode(self, value, etc, options) end

function OBJDEF:encode_pretty(value, etc, options) if type(self) ~= 'table' or self.__index ~= OBJDEF then OBJDEF:onEncodeError("JSON:encode_pretty must be called in method format", etc) end

--  -- If the user didn't pass in a table of decode options, use the default pretty ones --  if type(options) ~= 'table' then options = default_pretty_options end

return top_level_encode(self, value, etc, options) end

function OBJDEF.__tostring return "JSON encode/decode package" end

OBJDEF.__index = OBJDEF

function OBJDEF:new(args) local new = { }

if args then for key, val in pairs(args) do        new[key] = val end end

return setmetatable(new, OBJDEF) end

return OBJDEF:new

-- -- Version history: -- --  20161109.21   Oops, had a small boo-boo in the previous update. -- --  20161103.20   Used to silently ignore trailing garbage when decoding. Now fails via JSON:onTrailingGarbage --                http://seriot.ch/parsing_json.php -- --                Built-in error message about "expected comma or ']'" had mistakenly referred to '[' -- --                Updated the built-in error reporting to refer to bytes rather than characters. -- --                The decode method no longer assumes that error handlers abort. -- --                Made the VERSION string a string instead of a number --

--  20160916.19   Fixed the isNumber.__index assignment (thanks to Jack Taylor) --  --   20160730.18   Added JSON:forceString and JSON:forceNumber -- --  20160728.17   Added concatenation to the metatable for JSON:asNumber -- --  20160709.16   Could crash if not passed an options table (thanks jarno heikkinen ). -- --                Made JSON:asNumber a bit more resilient to being passed the results of itself. -- --  20160526.15   Added the ability to easily encode null values in JSON, via the new "null" encoding option. --                (Thanks to Adam B for bringing up the issue.) -- --                Added some support for very large numbers and precise floats via --                   JSON.decodeNumbersAsObjects --                   JSON.decodeIntegerStringificationLength --                   JSON.decodeDecimalStringificationLength -- --                Added the "stringsAreUtf8" encoding option. (Hat tip to http://lua-users.org/wiki/JsonModules ) -- --  20141223.14   The encode_pretty routine produced fine results for small datasets, but isn't really --                appropriate for anything large, so with help from Alex Aulbach I've made the encode routines --                more flexible, and changed the default encode_pretty to be more generally useful. -- --                Added a third 'options' argument to the encode and encode_pretty routines, to control --                how the encoding takes place. -- --                Updated docs to add assert call to the loadfile line, just as good practice so that --                if there is a problem loading JSON.lua, the appropriate error message will percolate up. -- --  20140920.13   Put back (in a way that doesn't cause warnings about unused variables) the author string, --                so that the source of the package, and its version number, are visible in compiled copies. -- --  20140911.12   Minor lua cleanup. --                Fixed internal reference to 'JSON.noKeyConversion' to reference 'self' instead of 'JSON'. --                (Thanks to SmugMug's David Parry for these.) -- --  20140418.11   JSON nulls embedded within an array were being ignored, such that --                    ["1",null,null,null,null,null,"seven"], --                would return --                    {1,"seven"} --                It's now fixed to properly return --                    {1, nil, nil, nil, nil, nil, "seven"} --                Thanks to "haddock" for catching the error. -- --  20140116.10   The user's JSON.assert wasn't always being used. Thanks to "blue" for the heads up. -- --  20131118.9    Update for Lua 5.3... it seems that tostring(2/1) produces "2.0" instead of "2", --                and this caused some problems. -- --  20131031.8    Unified the code for encode and encode_pretty; they had been stupidly separate, --                and had of course diverged (encode_pretty didn't get the fixes that encode got, so --                 sometimes produced incorrect results; thanks to Mattie for the heads up). -- --                Handle encoding tables with non-positive numeric keys (unlikely, but possible). -- --                If a table has both numeric and string keys, or its numeric keys are inappropriate --                (such as being non-positive or infinite), the numeric keys are turned into --                string keys appropriate for a JSON object. So, as before, --                        JSON:encode({ "one", "two", "three" }) --                produces the array --                        ["one","two","three"] --                but now something with mixed key types like --                        JSON:encode({ "one", "two", "three", SOMESTRING = "some string" })) --                 instead of throwing an error produces an object: --                         {"1":"one","2":"two","3":"three","SOMESTRING":"some string"} -- --                 To maintain the prior throw-an-error semantics, set --                      JSON.noKeyConversion = true --                 --   20131004.7    Release under a Creative Commons CC-BY license, which I should have done from day one, sorry. -- --   20130120.6    Comment update: added a link to the specific page on my blog where this code can --                 be found, so that folks who come across the code outside of my blog can find updates --                 more easily. -- --   20111207.5    Added support for the 'etc' arguments, for better error reporting. -- --   20110731.4    More feedback from David Kolf on how to make the tests for Nan/Infinity system independent. -- --  20110730.3    Incorporated feedback from David Kolf at http://lua-users.org/wiki/JsonModules: -- --                  * When encoding lua for JSON, Sparse numeric arrays are now handled by --                     spitting out full arrays, such that --                       JSON:encode({"one", "two", [10] = "ten"}) --                    returns --                       ["one","two",null,null,null,null,null,null,null,"ten"] -- --                    In 20100810.2 and earlier, only up to the first non-null value would have been retained. -- --                  * When encoding lua for JSON, numeric value NaN gets spit out as null, and infinity as "1+e9999". --                    Version 20100810.2 and earlier created invalid JSON in both cases. -- --                  * Unicode surrogate pairs are now detected when decoding JSON. -- --  20100810.2    added some checking to ensure that an invalid Unicode character couldn't leak in to the UTF-8 encoding -- --  20100731.1    initial public release --