From: Stefan Kanev <stefan.kanev@...>
Date: 2009-01-26T05:30:14+09:00
Subject: Re: How can I get the arguments passed to the caller.

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So, suppose I want to get evil and go dig into frames and so on. I've seen
ruby-debug do something close. Is there a part of the standard library that
allows you to introspect that way (if so, I could not find it), or a gem
maybe? And if not and I'm bend on writing C code to achieve it, where should
I start looking?

On Sun, Jan 25, 2009 at 9:39 PM, James Coglan <jcoglan@googlemail.com>wrote:

> > I have a rather weird question. I want to write a function that
> > programatically determines the arguments passed to its caller. Say, if i
> do
> >
> > $stuff = []
> >
> > def bar(arg)
> >  foo
> > end
> >
> > def foo
> >  first_arg = ....
> >  $stuff << first_arg
> > end
> >
> > bar(42)
> >
> > # By this point, $stuff would be [42]
>
>
>
> I think the closest you're going to get is for the calling function to pass
> its binding so that foo can read from it:
>
> def bar(*args)
>  foo(binding)
> end
> => nil
> def foo(env)
>  puts env.eval("args.first")
> end
> => nil
> bar 'something'
> something
>
> I don't think you can do this transparently. You can't even refer to the
> argument list within a single method (I'm thinking of the 'arguments'
> object
> in JavaScript) without mentioning the arguments by name.
>

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