From: gabriele renzi <surrender_it@...1.vip.ukl.yahoo.com>
Date: 2004-05-20T14:13:49+09:00
Subject: Re: How to duck type? - the psychology of static typing in Ruby

il Thu, 20 May 2004 07:33:31 +0900, Hal Fulton
<hal9000@hypermetrics.com> ha scritto::


>
>Well, here's one comment.
>
>   if foo()
>     def 5.collect
>       puts "I exist!"
>     end
>   end
>
>Of course, Fixnums can't have singleton methods now. Later, I think they
>may.
>
>The point is, methods may be added/deleted/redefined at runtime. This
>makes static checking very difficult in the general case.
>

I'd say, from an 'optimistic' perspective that this falls in what sean
sees as 'catch something is better than nothing'.

Note that this *is* a bug:

def foo(x)
 if x
  def 5.collect
   ..
  end
 end
 bar(5)
end


def bar(x)
 x.collect
end

what happens if we do foo(false)? 
NoSuchMethodError in bar.

FWIW, I would be happy to see something like rubylint/checker module,
not necessarily in the interpreter itself. I'd like:
ruby -rubylint program.rb

At least it should be possible to reach the same results similar tools
can reach.