lua解析json

自己写的lua解析json,带容错，如果要是用于格式检查，得修改下。很简单直接贴代码

--------------------------------------------------json解析----------------------------------------------------------
local function json2true(str,from,to)
return true, from+3
end

local function json2false(str,from,to)
return false, from+4
end

local function json2null(str, from, to)
return nil, from+3
end

local function json2nan(str, from, to)
return nul, from+2
end

local numberchars = {
['-'] = true,
['+'] = true,
['.'] = true,
['0'] = true,
['1'] = true,
['2'] = true,
['3'] = true,
['4'] = true,
['5'] = true,
['6'] = true,
['7'] = true,
['8'] = true,
['9'] = true,
}

local function json2number(str,from,to)
local i = from+1
while(i<=to) do
local char = string.sub(str, i, i)
if not numberchars[char] then
break
end
i = i + 1
end
local num = tonumber(string.sub(str, from, i-1))
if not num then
error(_format('json格式错误，不正确的数字, 错误位置:{from}', from))
end
return num, i-1
end

local function json2string(str,from,to)
local ignor = false
for i = from+1, to do
local char = string.sub(str, i, i)
if not ignor then
if char == '\"' then
return string.sub(str, from+1, i-1), i
elseif char == '\\' then
ignor = true
end
else
ignor = false
end
end
error(_format('json格式错误，字符串没有找到结尾, 错误位置:{from}', from))
end

local function json2array(str,from,to)
local result = {}
from = from or 1
local pos = from+1
local to = to or string.len(str)
while(pos<=to) do
local char = string.sub(str, pos, pos)
if char == '\"' then
result[#result+1], pos = json2string(str,pos,to)
--[[ elseif char == ' ' then

elseif char == ':' then

elseif char == ',' then]]
elseif char == '[' then
result[#result+1], pos = json2array(str,pos,to)
elseif char == '{' then
result[#result+1], pos = json2table(str,pos,to)
elseif char == ']' then
return result, pos
elseif (char=='f' or char=='F') then
result[#result+1], pos = json2false(str,pos,to)
elseif (char=='t' or char=='T') then
result[#result+1], pos = json2true(str,pos,to)
elseif (char=='n') then
result[#result+1], pos = json2null(str,pos,to)
elseif (char=='N') then
result[#result+1], pos = json2nan(str,pos,to)
elseif numberchars[char] then
result[#result+1], pos = json2number(str,pos,to)
end
pos = pos + 1
end
error(_format('json格式错误，表没有找到结尾, 错误位置:{from}', from))
end

function _G.json2table(str,from,to)
local result = {}
from = from or 1
local pos = from+1
local to = to or string.len(str)
local key
while(pos<=to) do
local char = string.sub(str, pos, pos)
if char == '\"' then
if not key then
key, pos = json2string(str,pos,to)
else
result[key], pos = json2string(str,pos,to)
key = nil
end
--[[ elseif char == ' ' then

elseif char == ':' then

elseif char == ',' then]]
elseif char == '[' then
if not key then
key, pos = json2array(str,pos,to)
else
result[key], pos = json2array(str,pos,to)
key = nil
end
elseif char == '{' then
if not key then
key, pos = json2table(str,pos,to)
else
result[key], pos = json2table(str,pos,to)
key = nil
end
elseif char == '}' then
return result, pos
elseif (char=='f' or char=='F') then
result[key], pos = json2false(str,pos,to)
key = nil
elseif (char=='t' or char=='T') then
result[key], pos = json2true(str,pos,to)
key = nil
elseif (char=='n') then
result[key], pos = json2null(str,pos,to)
key = nil
elseif (char=='N') then
result[key], pos = json2nan(str,pos,to)
key = nil
elseif numberchars[char] then
if not key then
key, pos = json2number(str,pos,to)
else
result[key], pos = json2number(str,pos,to)
key = nil
end
end
pos = pos + 1
end
error(_format('json格式错误，表没有找到结尾, 错误位置:{from}', from))
end

--json格式中表示字符串不能使用单引号
local jsonfuncs={
['\"']=json2string,
['[']=json2array,
['{']=json2table,
['f']=json2false,
['F']=json2false,
['t']=json2true,
['T']=json2true,
}

function _G.json2lua(str)
local char = string.sub(str, 1, 1)
local func=jsonfuncs[char]
if func then
return func(str, 1, string.len(str))
end
if numberchars[char] then
return json2number(str, 1, string.len(str))
end
end

--[[
-----test-------
print("test json2lua");
dump(json2lua("false"));
dump(json2lua("true"));
dump(json2lua("{\"abc\":\"fge\"}"));
dump(json2lua("[\"afv\", 1, \"drrg\", false]"));
dump(json2lua("1234"));
dump(json2lua("null"));]]