La documentation pour ce module peut être créée à Module:json/Documentation
--
-- Copyright (c) 2020 rxi
--
-- 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.
--
local json = { _version = "0.1.2" }
-------------------------------------------------------------------------------
-- Encode
-------------------------------------------------------------------------------
local encode
local escape_char_map = {
= "\\",
= "\"",
= "b",
= "f",
= "n",
= "r",
= "t",
}
local escape_char_map_inv = { = "/" }
for k, v in pairs(escape_char_map) do
escape_char_map_inv = k
end
local function escape_char(c)
return "\\" .. (escape_char_map or string.format("u%04x", c:byte()))
end
local function encode_nil(val)
return "null"
end
local function encode_table(val, stack)
local res = {}
stack = stack or {}
-- Circular reference?
if stack then error("circular reference") end
stack = true
if rawget(val, 1) ~= nil or next(val) == nil then
-- Treat as array -- check keys are valid and it is not sparse
local n = 0
for k in pairs(val) do
if type(k) ~= "number" then
error("invalid table: mixed or invalid key types")
end
n = n + 1
end
if n ~= #val then
error("invalid table: sparse array")
end
-- Encode
for i, v in ipairs(val) do
table.insert(res, encode(v, stack))
end
stack = nil
return ""
else
-- Treat as an object
for k, v in pairs(val) do
if type(k) ~= "string" then
error("invalid table: mixed or invalid key types")
end
table.insert(res, encode(k, stack) .. ":" .. encode(v, stack))
end
stack = nil
return "{" .. table.concat(res, ",") .. "}"
end
end
local function encode_string(val)
return '"' .. val:gsub('', escape_char) .. '"'
end
local function encode_number(val)
-- Check for NaN, -inf and inf
if val ~= val or val <= -math.huge or val >= math.huge then
error("unexpected number value '" .. tostring(val) .. "'")
end
return string.format("%.14g", val)
end
local type_func_map = {
= encode_nil,
= encode_table,
= encode_string,
= encode_number,
= tostring,
}
encode = function(val, stack)
local t = type(val)
local f = type_func_map
if f then
return f(val, stack)
end
error("unexpected type '" .. t .. "'")
end
function json.encode(val)
return ( encode(val) )
end
-------------------------------------------------------------------------------
-- Decode
-------------------------------------------------------------------------------
local parse
local function create_set(...)
local res = {}
for i = 1, select("#", ...) do
res = true
end
return res
end
local space_chars = create_set(" ", "\t", "\r", "\n")
local delim_chars = create_set(" ", "\t", "\r", "\n", "]", "}", ",")
local escape_chars = create_set("\\", "/", '"', "b", "f", "n", "r", "t", "u")
local literals = create_set("true", "false", "null")
local literal_map = {
= true,
= false,
= nil,
}
local function next_char(str, idx, set, negate)
for i = idx, #str do
if set ~= negate then
return i
end
end
return #str + 1
end
local function decode_error(str, idx, msg)
local line_count = 1
local col_count = 1
for i = 1, idx - 1 do
col_count = col_count + 1
if str:sub(i, i) == "\n" then
line_count = line_count + 1
col_count = 1
end
end
error( string.format("%s at line %d col %d", msg, line_count, col_count) )
end
local function codepoint_to_utf8(n)
-- http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=iws-appendixa
local f = math.floor
if n <= 0x7f then
return string.char(n)
elseif n <= 0x7ff then
return string.char(f(n / 64) + 192, n % 64 + 128)
elseif n <= 0xffff then
return string.char(f(n / 4096) + 224, f(n % 4096 / 64) + 128, n % 64 + 128)
elseif n <= 0x10ffff then
return string.char(f(n / 262144) + 240, f(n % 262144 / 4096) + 128,
f(n % 4096 / 64) + 128, n % 64 + 128)
end
error( string.format("invalid unicode codepoint '%x'", n) )
end
local function parse_unicode_escape(s)
local n1 = tonumber( s:sub(1, 4), 16 )
local n2 = tonumber( s:sub(7, 10), 16 )
-- Surrogate pair?
if n2 then
return codepoint_to_utf8((n1 - 0xd800) * 0x400 + (n2 - 0xdc00) + 0x10000)
else
return codepoint_to_utf8(n1)
end
end
local function parse_string(str, i)
local res = ""
local j = i + 1
local k = j
while j <= #str do
local x = str:byte(j)
if x < 32 then
decode_error(str, j, "control character in string")
elseif x == 92 then -- `\`: Escape
res = res .. str:sub(k, j - 1)
j = j + 1
local c = str:sub(j, j)
if c == "u" then
local hex = str:match("^%x%x\\u%x%x%x%x", j + 1)
or str:match("^%x%x%x%x", j + 1)
or decode_error(str, j - 1, "invalid unicode escape in string")
res = res .. parse_unicode_escape(hex)
j = j + #hex
else
if not escape_chars then
decode_error(str, j - 1, "invalid escape char '" .. c .. "' in string")
end
res = res .. escape_char_map_inv
end
k = j + 1
elseif x == 34 then -- `"`: End of string
res = res .. str:sub(k, j - 1)
return res, j + 1
end
j = j + 1
end
decode_error(str, i, "expected closing quote for string")
end
local function parse_number(str, i)
local x = next_char(str, i, delim_chars)
local s = str:sub(i, x - 1)
local n = tonumber(s)
if not n then
decode_error(str, i, "invalid number '" .. s .. "'")
end
return n, x
end
local function parse_literal(str, i)
local x = next_char(str, i, delim_chars)
local word = str:sub(i, x - 1)
if not literals then
decode_error(str, i, "invalid literal '" .. word .. "'")
end
return literal_map, x
end
local function parse_array(str, i)
local res = {}
local n = 1
i = i + 1
while 1 do
local x
i = next_char(str, i, space_chars, true)
-- Empty / end of array?
if str:sub(i, i) == "]" then
i = i + 1
break
end
-- Read token
x, i = parse(str, i)
res = x
n = n + 1
-- Next token
i = next_char(str, i, space_chars, true)
local chr = str:sub(i, i)
i = i + 1
if chr == "]" then break end
if chr ~= "," then decode_error(str, i, "expected ']' or ','") end
end
return res, i
end
local function parse_object(str, i)
local res = {}
i = i + 1
while 1 do
local key, val
i = next_char(str, i, space_chars, true)
-- Empty / end of object?
if str:sub(i, i) == "}" then
i = i + 1
break
end
-- Read key
if str:sub(i, i) ~= '"' then
decode_error(str, i, "expected string for key")
end
key, i = parse(str, i)
-- Read ':' delimiter
i = next_char(str, i, space_chars, true)
if str:sub(i, i) ~= ":" then
decode_error(str, i, "expected ':' after key")
end
i = next_char(str, i + 1, space_chars, true)
-- Read value
val, i = parse(str, i)
-- Set
res = val
-- Next token
i = next_char(str, i, space_chars, true)
local chr = str:sub(i, i)
i = i + 1
if chr == "}" then break end
if chr ~= "," then decode_error(str, i, "expected '}' or ','") end
end
return res, i
end
local char_func_map = {
= parse_string,
= parse_number,
= parse_number,
= parse_number,
= parse_number,
= parse_number,
= parse_number,
= parse_number,
= parse_number,
= parse_number,
= parse_number,
= parse_number,
= parse_literal,
= parse_literal,
= parse_literal,
= parse_array,
= parse_object,
}
parse = function(str, idx)
local chr = str:sub(idx, idx)
local f = char_func_map
if f then
return f(str, idx)
end
decode_error(str, idx, "unexpected character '" .. chr .. "'")
end
function json.decode(str)
if type(str) ~= "string" then
error("expected argument of type string, got " .. type(str))
end
local res, idx = parse(str, next_char(str, 1, space_chars, true))
idx = next_char(str, idx, space_chars, true)
if idx <= #str then
decode_error(str, idx, "trailing garbage")
end
return res
end
return json