From: Stephan Mueller <d454d@...>
Date: 2005-08-07T04:41:08+09:00
Subject: Re: polymorphism and/or named parameters: the ruby way?

Hi Eric,

* Eric Mahurin <eric_mahurin@yahoo.com> [050806 20:25]:

> What you are talking about is really method overloading not
> polymorphism in my opinion.

Yes, I agree. :)

> My take on the "ruby way" is to not overload methods by type
> like you can easily do in java.  Instead you just make multiple
> distinct methods with each method taking its own "type".  This
> give maximal flexibility with duck-typing.
>
> There is no reason you can't make multiple new type class
> methods that call the normal "new" method - you wouldn't need
> an initialize in that case.

Something like this?

 class MyClass

   def new_s(str)
     me = super
     # do sth with str
     return me     
   end

   def new_i(int)
     me = super
     # do sth with int
     return me     
   end

   ...  

> The closest you can come to named parameters is by using a hash
> (right now, at least):
> 
> def test(hash)
>     if hash[:p1]
>         ...
>     elsif hash[:p2]
>         ...
>     end
> end
> 
> test(:p1=>500)

Okay, looks quite good for me. Not much more effort than real named
params.

Thanks!

Steph.