From: dblack@...
Date: 2007-01-13T01:12:13+09:00
Subject: Re: Why doesn't Ruby allow for overloaded methods within a class

Hi --

On Fri, 12 Jan 2007, Wes Gamble wrote:

> (from a Java refugee)
>
> All,
>
> I've done quite a bit of googling and read a bunch of posts about this,
> but I'm looking for a simple explanation of why Ruby doesn't support
> method overloading within a class to allow methods with the same name
> but different numbers of arguments.  I understand that you can't do
> method overloading with the same # of arguments since you don't know any
> "types" of input parameters when you invoke a method.
>
> But...it seems like you could allow it for different numbers of input
> parameters.
>
> Here's an example of what I mean:
> class Foo
>  def methname(x,y)
>    ...
>  end
>
>  def methname(x, y, z)
>    ...
>  end
> end
>
> I'm comfortable with how to implement this using a method with varargs
> and appropriate logic, and I'm aware of arguments that the methods
> should probably be different in name if their set of input parameters
> are of different size.
>
> But it seems like this kind method overloading would be doable in Ruby.
> Is it possible?
> Is it not available because there's a feeling that it isn't needed?

I've never extensively used any language that has this feature, but
it's always struck me as a bit strange, and very brittle.  What if you
want two method behaviors, but both behaviors involve having the same
number of arguments?  It's always seemed to me a bit like having
methods dispatch on what letter of the alphabet their parameters begin
with.

So... I guess my view is that Ruby has evolved beyond it, though there
may be some use for it that I'm just not seeing.


David

-- 
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