From: "Chr. Rippel" <chr_news@...>
Date: 2002-01-30T20:43:49+09:00
Subject: Re: Proc hash bug?

<ntalbott@rolemodelsoft.com> wrote in
....
> > Current implementation converts Proc <-> Block for each time, 
> > so that &var Proc is generated each time.  This might change 
> > in the future, but I cannot ensure the hash (or identity) equality.
> 
> This breaks POLS for me in a big way (but maybe not for you). I expect
> the block to remain the same whether I pass it in through the arguments
> as an object, or whether I use & to associate it directly with the
> method call. I can see why, implementation-wise, it might be easier to
> make them different, but I can't see from a user's perspective how the
> behavior makes sense.
I guess by now I expect my POLS to be broken, in particular when comes
to issue of hashing.  
....
> to go with a less attractive alternative, but I guess I'm looking either
> for more of an explanation or a fix. I'd submit an RCR for it if you
> think it's worthwhile.

If it was me I would be trying to avoid envoking the 
proc <-> conversion. Of course there is some sort of fix - 
which is likely very dangerous (you probably can improve 
on it though)

---
P = proc {P}
def bla(a, & b)
   hsh = { a => 3}
   p hsh[b]
end

class Proc
  def hash
    inspect.sub(/^(#<Proc:)/){''}.sub(/(>)$/){''}.to_i(16)
  end
  def eql?(other)
    unless other.instance_of? (type)
      false
    else
      hash == other.hash
    end
  end
end

bla (P,&P) # => 3
----    

/Christoph