Conditional Function Definition

["David F" <kumpuu@...>]

On 18/03/17 11:56 PM, Sean Conner wrote:
>It was thus said that the Great Marcello Chiuminatto once stated:
>> Hi everybody
>> 
>> Maybe someone can help with this.
>> 
>> I have "polymorphism" situation where I want to define a function that
>> depending on a condition will have different signature and behaviors
>> 
>> I would like something like this, but unfortunately does not work. Is
>> there any other way to implement this in lua?
>> 
>> MyClass = {
>> }
>> 
>> If somecondition == 1 then
>>   MyClass.f = function (self, x)
>>                return x*2 
>>   end
>> end
>> 
>> if somecondition == 2 then
>>   MyClass.f = function (self, x,y)
>>                return x*y
>>   end
>> end
>> 
>> if somecondition == 3 then 
>>   -- this case escapes from polymorphism since have the same signature
>>   -- that f in somecondition == 2, but I need this anyway.
>> 
>>   MyClass.f = function (self, x,y)
>>                return x/1
>>   end
>> end
>
>  What do you mean by "does not work"?  What error are you seeing?  Because
>from what I can see, this will work (you can always pass more parameters
>than a Lua function expects---said function will just ignore the extra
>parameters).  
>
>  -spc

I think he wants something like

MyClass = {
  f = function(self, x, y)
    if somecondition == 1 then return x*2 end
    if somecondition == 2 then return x*y end
    if somecondition == 3 then return x/1 end
  end
}