From: "Radosław Bułat" <radek.bulat@...>
Date: 2008-12-18T22:05:59+09:00
Subject: [ruby-core:20642] Re: Proposal: Proc#bind

As far as I understand Pawel proporsal he wants to do smth like this:

proc = Proc.new { puts self.inspect }
a = [1, 2, 3]
h = { "foo" => "bar" }
s = "foo"

p_a = proc.bind(a)
p_h = proc.bind(h)
p_s = proc.bind(s)

p_a.call # => [1, 2, 3]
p_h.call # => {"foo" => "bar"}
p_s.call # => "foo"


I know that in ruby 1.8/1.9 i can do this:

 class Proc
   def bind(other)
     return Proc.new do
         other.instance_eval(&self)
     end
   end
 end

and it will work:

proc.bind([]).call
proc.bind({}).call

But the problem is in implementation because it create some chain. It
call's original proc with instance_eval. So after several
proc.bind(...).bind(...) we have some unnecessary calls.

Is there any problem to add this to Ruby core? Maybe some issue with
implementing it? I guess it shouldn't because for example class
UnboundedMethod have #bind method and Method have #unbind method. It
should works like this (but probably #unbind doesn't make sens because
there is no such thing like UnboundedProc).

Any comments on this? Matz and the rest?
-- 
Pozdrawiam

Rados�aw Bu�at
http://radarek.jogger.pl - m�j blog