Lua-我如何获得退货? [英] Lua - How can I grab any return?

问题描述

我有兴趣获取函数的任何返回格式.例如

I am interested in grabbing any return format of a function. For example

function foo()
  return 1
end

local result = foo() -- foo is numeric 1

function foo()
  return {1,2,3}
end
local result1, result2, result3 = foo()
local result = foo() -- this is bad as result is `1` but `2` and `3` are lost

function foo()
  return 1, 2, 3
end
local result = foo() -- foo is a table with all the numbers, that's ok

我正在构建一个探查器，它将使用代理函数覆盖函数，但是我需要知道返回的数据，然后检查它的type()并进行相应的访问`，但是从代码中可以看出，我无法访问所有一种方法有3种情况.有吗?

I am building a profiler which will overwrite functions with proxy functions but I need to know the data returned, then check type() of it and access accordingly` but from the code it can be seen that I am unable to access all 3 situations with one method. Is there any ?

推荐答案

如果知道最大的回报数，请使用类似的

If the maximum number of returns is known, use something like

v1,v2,v3 = foo()

，但是您将无法判断foo返回的是两个还是三个，最后一个为nil.

but you won't be able to tell whether foo returned two values or three, with the last one being nil.

可靠的解决方案是收集表中的所有收益:

The robust solution is to collect all returns in a table:

v = table.pack(foo())

然后v.n包含返回值的数量，包括所有nil.

Then v.n contains the number of returned values, including all nils.

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