From: Robert Klemme <bob.news@...>
Date: 2005-01-12T01:36:25+09:00
Subject: Re: Variable Arguments


<rohitlodha@hotwireindia.com> schrieb im Newsbeitrag
news:000a01c4f7fa$30251dc0$1a87103d@vubydump...
> Hi
>
> Ruby has a variable argument syntax as well as fixed number of arguments
> syntax. The caller does not know about how the called function's syntax.

The caller can in fact know the number of arguments at runtime:

>> class Foo
>> def f1(a)end
>> def f2(*a)end
>> def f3(a,*b)end
>> end
=> nil
>> f=Foo.new
=> #<Foo:0x10183158>
>> f.method("f1").arity
=> 1
>> f.method("f2").arity
=> -1
>> f.method("f3").arity
=> -2

And you'll see an error if the arguments passed do not match:

>> f.f1(1,2,3)
ArgumentError: wrong number of arguments(3 for 1)
        from (irb):11:in `f1'
        from (irb):11

> In case of variable arguments, it is expected caller to provide with
> number of arguments while for the other case it might not.

I'm sorry, I don't understand what you mean by this.

> Since, I am writing a VM for Ruby, I would like to know how should one
> handle this problem?

As I'm currently mystified by your question I can't come up with an
answer.  Could you please clarify this?  And what kind of VM are you
writing?

Kind regards

    robert