From: "David A. Black" <dblack@...>
Date: 2004-10-05T01:13:55+09:00
Subject: Re: Too Many Ways?

Hi --

On Tue, 5 Oct 2004 Ara.T.Howard@noaa.gov wrote:

> On Mon, 4 Oct 2004, David A. Black wrote:
> 
> > I have to admit (and my lack of C++, Java, etc. is probably showing through
> > here -- i.e., I'm perfectly willing to believe there's something fundamental
> > I'm just missing), I have never understood the idea of differentiating
> > methods by number of arguments.  To me it's sort of like differentiating
> > them based on what letters the argument names begin with.  What if two
> > slightly different forms of the method both, by chance, took three
> > arguments?  Would one add a dummy argument?
> 
> no - because you would also have a different signature (else the methods
> wouldn't be 'slightly different' (probably) :
> 
>    //
>    // move from src to preallocated dest - leaving src untouched
>    //
>      int move (const char * const src, const char * dest);
> 
>    //
>    // move from src to dest - creating dest and freeing src
>    //
>      int move (char * src, char * dest);
> 
> the idea is this - the compiler can tell you two things about your methods at
> compile time : the types of the arguments and the number of them.  

[snip rest of very informative summary]

OK, the examples with compile-time type checking explain why it might
exist in other languages, and also why it continues to feel like a bad
fit for Ruby.  

> it can use
> this infomation to generate a case statement for you - eg it can know which
> one to call freeing you from writing code like
> 
>    case argv.size
>      when 2
>        arg0, arg1 = argv
>        case arg0
>          when String
>          ...
>        end
>      when 3
>          ...
>          ...
>    end

I hope I'm already free of that, so that's another reason why I
haven't felt the need for this :-)

Thanks --


David

-- 
David A. Black
dblack@wobblini.net