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Updated Lua/JSON module

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Luca Deri 2015-10-24 09:14:13 +02:00
parent 1ae7e33fca
commit 006da523c0
1 changed files with 112 additions and 201 deletions
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313
scripts/lua/modules/dkjson.lua
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@ -1,178 +1,23 @@
-- Module options:
local always_try_using_lpeg = true
local register_global_module_table = false
local global_module_name = 'json'
-- 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 2.3*
Version 2.5
In the default configuration this module writes no global values, not even
the module table. Import it using
json = require ("dkjson")
In environments where `require` or a similiar function are not available
and you cannot receive the return value of the module, you can set the
option `register_global_module_table` to `true`. The module table will
then be saved in the global variable with the name given by the option
`global_module_name`.
Exported functions and values:
`json.encode (object [, state])`
--------------------------------
Create a string representing the object. `Object` can be a table,
a string, a number, a boolean, `nil`, `json.null` or any object with
a function `__tojson` in its metatable. A table can only use strings
and numbers as keys and its values have to be valid objects as
well. It raises an error for any invalid data types or reference
cycles.
`state` is an optional table with the following fields:
- `indent`
When `indent` (a boolean) is set, the created string will contain
newlines and indentations. Otherwise it will be one long line.
- `keyorder`
`keyorder` is an array to specify the ordering of keys in the
encoded output. If an object has keys which are not in this array
they are written after the sorted keys.
- `level`
This is the initial level of indentation used when `indent` is
set. For each level two spaces are added. When absent it is set
to 0.
- `buffer`
`buffer` is an array to store the strings for the result so they
can be concatenated at once. When it isn't given, the encode
function will create it temporary and will return the
concatenated result.
- `bufferlen`
When `bufferlen` is set, it has to be the index of the last
element of `buffer`.
- `tables`
`tables` is a set to detect reference cycles. It is created
temporary when absent. Every table that is currently processed
is used as key, the value is `true`.
When `state.buffer` was set, the return value will be `true` on
success. Without `state.buffer` the return value will be a string.
`json.decode (string [, position [, null]])`
--------------------------------------------
Decode `string` starting at `position` or at 1 if `position` was
omitted.
`null` is an optional value to be returned for null values. The
default is `nil`, but you could set it to `json.null` or any other
value.
The return values are the object or `nil`, the position of the next
character that doesn't belong to the object, and in case of errors
an error message.
Two metatables are created. Every array or object that is decoded gets
a metatable with the `__jsontype` field set to either `array` or
`object`. If you want to provide your own metatables use the syntax
json.decode (string, position, null, objectmeta, arraymeta)
To prevent the assigning of metatables pass `nil`:
json.decode (string, position, null, nil)
`<metatable>.__jsonorder`
-------------------------
`__jsonorder` can overwrite the `keyorder` for a specific table.
`<metatable>.__jsontype`
------------------------
`__jsontype` can be either `"array"` or `"object"`. This value is only
checked for empty tables. (The default for empty tables is `"array"`).
`<metatable>.__tojson (self, state)`
------------------------------------
You can provide your own `__tojson` function in a metatable. In this
function you can either add directly to the buffer and return true,
or you can return a string. On errors nil and a message should be
returned.
`json.null`
-----------
You can use this value for setting explicit `null` values.
`json.version`
--------------
Set to `"dkjson 2.3"`.
`json.quotestring (string)`
---------------------------
Quote a UTF-8 string and escape critical characters using JSON
escape sequences. This function is only necessary when you build
your own `__tojson` functions.
`json.addnewline (state)`
-------------------------
When `state.indent` is set, add a newline to `state.buffer` and spaces
according to `state.level`.
LPeg support
------------
When the local configuration variable `always_try_using_lpeg` is set,
this module tries to load LPeg to replace the `decode` function. The
speed increase is significant. You can get the LPeg module at
<http://www.inf.puc-rio.br/~roberto/lpeg/>.
When LPeg couldn't be loaded, the pure Lua functions stay active.
In case you don't want this module to require LPeg on its own,
disable the option `always_try_using_lpeg` in the options section at
the top of the module.
In this case you can later load LPeg support using
### `json.use_lpeg ()`
Require the LPeg module and replace the functions `quotestring` and
and `decode` with functions that use LPeg patterns.
This function returns the module table, so you can load the module
using:
json = require "dkjson".use_lpeg()
Alternatively you can use `pcall` so the JSON module still works when
LPeg isn't found.
json = require "dkjson"
pcall (json.use_lpeg)
### `json.using_lpeg`
This variable is set to `true` when LPeg was loaded successfully.
---------------------------------------------------------------------
Contact
-------
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*
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
@ -194,13 +39,7 @@ 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.
<!-- This documentation can be parsed using Markdown to generate HTML.
The source code is enclosed in a HTML comment so it won't be displayed
by browsers, but it should be removed from the final HTML file as
it isn't a valid HTML comment (and wastes space).
-->
<!--]==]
--]==]
-- global dependencies:
local pairs, type, tostring, tonumber, getmetatable, setmetatable, rawset =
@ -210,9 +49,10 @@ 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 2.3" }
local json = { version = "dkjson 2.5" }
if register_global_module_table then
_G[global_module_name] = json
@ -318,6 +158,39 @@ local function quotestring (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)
@ -334,7 +207,7 @@ end
local encode2 -- forward declaration
local function addpair (key, value, prev, indent, level, buffer, buflen, tables, globalorder)
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."
@ -348,31 +221,50 @@ local function addpair (key, value, prev, indent, level, buffer, buflen, tables,
end
buffer[buflen+1] = quotestring (key)
buffer[buflen+2] = ":"
return encode2 (value, indent, level, buffer, buflen + 2, tables, globalorder)
return encode2 (value, indent, level, buffer, buflen + 2, tables, globalorder, state)
end
encode2 = function (value, indent, level, buffer, buflen, tables, globalorder)
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 nil, "reference cycle"
return exception('reference cycle', value, state, buffer, buflen)
end
tables[value] = true
local state = {
indent = indent, level = level, buffer = buffer,
bufferlen = buflen, tables = tables, keyorder = globalorder
}
state.bufferlen = buflen
local ret, msg = valtojson (value, state)
if not ret then return nil, msg end
if not ret then return exception('custom encoder failed', value, state, buffer, buflen, msg) end
tables[value] = nil
buflen = state.bufferlen
if type (ret) == 'string' then
buflen = buflen + 1
buffer[buflen] = ret
end
buflen = appendcustom(ret, buffer, state)
elseif value == nil then
buflen = buflen + 1
buffer[buflen] = "null"
@ -382,7 +274,7 @@ encode2 = function (value, indent, level, buffer, buflen, tables, globalorder)
-- This is the behaviour of the original JSON implementation.
s = "null"
else
s = tostring (value)
s = num2str (value)
end
buflen = buflen + 1
buffer[buflen] = s
@ -394,7 +286,7 @@ encode2 = function (value, indent, level, buffer, buflen, tables, globalorder)
buffer[buflen] = quotestring (value)
elseif valtype == 'table' then
if tables[value] then
return nil, "reference cycle"
return exception('reference cycle', value, state, buffer, buflen)
end
tables[value] = true
level = level + 1
@ -407,7 +299,7 @@ encode2 = function (value, indent, level, buffer, buflen, tables, globalorder)
buflen = buflen + 1
buffer[buflen] = "["
for i = 1, n do
buflen, msg = encode2 (value[i], indent, level, buffer, buflen, tables, globalorder)
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
@ -429,20 +321,20 @@ encode2 = function (value, indent, level, buffer, buflen, tables, globalorder)
local v = value[k]
if v then
used[k] = true
buflen, msg = addpair (k, v, prev, indent, level, buffer, buflen, tables, globalorder)
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)
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)
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
@ -455,7 +347,8 @@ encode2 = function (value, indent, level, buffer, buflen, tables, globalorder)
end
tables[value] = nil
else
return nil, "type '" .. valtype .. "' is not supported by JSON."
return exception ('unsupported type', value, state, buffer, buflen,
"type '" .. valtype .. "' is not supported by JSON.")
end
return buflen
end
@ -464,14 +357,18 @@ 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)
buffer, state.bufferlen or 0, state.tables or {}, state.keyorder, state)
if not ret then
error (msg, 2)
elseif oldbuffer then
elseif oldbuffer == buffer then
state.bufferlen = ret
return true
else
state.bufferlen = nil
state.buffer = nil
return concat (buffer)
end
end
@ -499,9 +396,17 @@ local function scanwhite (str, pos)
while true do
pos = strfind (str, "%S", pos)
if not pos then return nil end
if strsub (str, pos, pos + 2) == "\239\187\191" then
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
@ -659,7 +564,7 @@ scanvalue = function (str, pos, nullval, objectmeta, arraymeta)
else
local pstart, pend = strfind (str, "^%-?[%d%.]+[eE]?[%+%-]?%d*", pos)
if pstart then
local number = tonumber (strsub (str, pstart, pend))
local number = str2num (strsub (str, pstart, pend))
if number then
return number, pend + 1
end
@ -694,8 +599,13 @@ 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, V = g.P, g.S, g.R, g.V
local P, S, R = g.P, g.S, g.R
local function ErrorCall (str, pos, msg, state)
if not state.msg then
@ -709,7 +619,9 @@ function json.use_lpeg ()
return g.Cmt (g.Cc (msg) * g.Carg (2), ErrorCall)
end
local Space = (S" \n\r\t" + P"\239\187\191")^0
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
@ -732,7 +644,7 @@ function json.use_lpeg ()
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))/tonumber
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
@ -800,4 +712,3 @@ end
return json
-->