From: Eric Mahurin <eric_mahurin@...>
Date: 2005-10-27T01:07:49+09:00
Subject: Re: A comparison by example of keyword argument styles

--- Trans <transfire@gmail.com> wrote:

> 
> Eric Mahurin wrote:
> > The "method" above is not meant to mean whatever method you
> > feel like.  I'm talking about Object#method that returns a
> > Method object for the method name/symbol given as an
> argument.
> 
> Ah, I see. I misinterpreted what you were asking for. Then
> try:
> 
>   define_method(:foo,&obj.method(:bar).to_proc)
> 
> T.

That's the ticket.  I thought &method would be the same as
&(method.to_proc) - they both convert a Method to a Proc.  But
I guess Method#to_proc does some isolation so that
define_method doesn't change self.  We can also use this same
technique to give define_method a Proc where we want to leave
self alone:

me = lambda { self }
me.call # => main

C = Class.new{
  # Proc#method(:call) is effectively Proc#to_method
  define_method(:foo,me.method(:call).to_proc)
  define_method(:bar,me)
}

C.new.foo # => main
C.new.bar # => #<C:0x40220d54>

Now if 1.8 just had Proc's that could take blocks, I'd be able
to get rid of some of my eval("def ...") statements and replace
them with define_method.

In 1.9, I think the above define_method/#to_proc way is the
best way to do simple delegation.




		
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