From: Robert Dober <robert.dober@...>
Date: 2007-05-30T15:22:07+09:00
Subject: Re: True arity

On 5/29/07, Daniel DeLorme <dan-ml@dan42.com> wrote:
> Robert Dober wrote:
> > On 5/29/07, Daniel DeLorme <dan-ml@dan42.com> wrote:
> >> Is there a way to get the *maximum* number of arguments that a method
> >> can receive? Method#arity only gives the lower bound...
> >
> > I am afraid I fail to understand, what would you define as the maximum?
> >
> > def a(a)...  I would say the maximum is 1 which is the arity
> > def b(*b)   arity is -1 but what would the maximum of parameters be?
> > def c(c,*d) arity = -2 but some question as above.
> >
> > The question is, what would you like to achieve?
>
> In the last 2 cases you give the maximum would be Infinity. But in a
> case like this:
>    def foo(a, b=nil, c=nil)
I know I missed something :(, indeed a good question, thx for
explaining to a dummy ;).
> the maximum would be 3 but arity only gives me -2 which means "this
> method has 1 required argument". If I invoke the method like:
>    foo(*args)
> I want to know for what size of args is this valid? It would be nice if
> arity returned a Range object (1..3)
>
> Daniel
>
>
Cheers
Robert

-- 
You see things; and you say Why?
But I dream things that never were; and I say Why not?
-- George Bernard Shaw