Lua dump table(类似PHP中的print_r/var_export)
会PHP的人都知道PHP中的print_r/var_export函数，可以方便的用于打印数组或导出变量，Lua中没有提供，实际应用中却是很多时候需要类似的功能。
今天便封装了个简单函数，实现类似功能，用来打印/导出table：
-- dump.lua--[[dump对象@param mixed obj@return string]]function debug.dump(obj) local getIndent, quoteStr, wrapKey, wrapVal, dumpObj getIndent = function(level) return string.rep("\t", level) end quoteStr = function(str) return '"' .. string.gsub(str, '"', '\\"') .. '"' end wrapKey = function(val) if type(val) == "number" then return "[" .. val .. "]" elseif type(val) == "string" then return "[" .. quoteStr(val) .. "]" else return "[" .. tostring(val) .. "]" end end wrapVal = function(val, level) if type(val) == "table" then return dumpObj(val, level) elseif type(val) == "number" then return val elseif type(val) == "string" then return quoteStr(val) else return tostring(val) end end dumpObj = function(obj, level) if type(obj) ~= "table" then return wrapVal(obj) end level = level + 1 local tokens = {} tokens[#tokens + 1] = "{" for k, v in pairs(obj) do tokens[#tokens + 1] = getIndent(level) .. wrapKey(k) .. " = " .. wrapVal(v, level) .. "," end tokens[#tokens + 1] = getIndent(level - 1) .. "}" return table.concat(tokens, "\n") end return dumpObj(obj, 0)end测试代码：
-- test.lualocal obj = { string = "hello", int = 9527, float = 3.1415, bool = true, table = { 1, 2, 3, { a = 21, b = 22, c = 23, }, }, [88] = 88888, [9.7] = 22222,}print(debug.dump(obj))输出结果：
{ ["float"] = 3.1415, [9.7] = 22222, ["string"] = "hello", [88] = 88888, ["bool"] = true, ["int"] = 9527, ["table"] = { [1] = 1, [2] = 2, [3] = 3, [4] = { ["b"] = 22, ["a"] = 21, ["c"] = 23, }, },}函数特点：
1、理论上支持无限级table嵌套
2、格式化输出，可读性好
3、输出结果可直接用于lua代码
4、function、userdata、thread类型tostring输出
