[Lua] try catch实现

参考了https://blog.csdn.net/waruqi/article/details/53649634这里的代码，但实际使用时还有些问题，修改后在此记录一下。

 -- 异常捕获
 function try(block)
     -- get the try function
     local try = block[]
     assert(try)

     -- get catch and finally functions
     local funcs = block[]

     -- try to call it
     local ok, errors = xpcall(try, debug.traceback)
     if not ok then
         -- run the catch function
         if funcs and funcs.catch then
             funcs.catch(errors)
         end
     end

     -- run the finally function
     if funcs and funcs.finally then
         funcs.finally(ok, errors)
     end

     -- ok?
     if ok then
         return errors
     end
 end

 function test()
 try
     {
         function ()
             xxx()
         end,
         {
             -- 发生异常后，被执行
             catch = function (errors)
                 print("LUA Exception : " .. errors)
             end,

             finally = function (ok, errors)
                 -- do sth.
                 print("finally can work")
             end
         },
     }
 print("I can print normally!")
 end

 test()

异常捕获代码+测试代码

调用test()后，运行结果如下：

又改了一版，格式输入看起来更容易理解，代码如下：

 -- 异常捕获
 function try1(block)
     local main = block.main
     local catch = block.catch
     local finally = block.finally

     assert(main)

     -- try to call it
     local ok, errors = xpcall(main, debug.traceback)
     if not ok then
         -- run the catch function
         if catch then
             catch(errors)
         end
     end

     -- run the finally function
     if finally then
         finally(ok, errors)
     end

     -- ok?
     if ok then
         return errors
     end
 end

 function test1()
 try1{
         main = function ()
             xxx()
         end,
         catch = function (errors)
             print("catch : " .. errors)
         end,
         finally = function (ok, errors)
             print("finally : " .. tostring(ok))
         end,
     }
 print("I can print normally!")
 end

 test1()

新版try-catch

打印结果如下：