From: Sean O'Halpin <sean.ohalpin@...>
Date: 2005-11-15T00:45:32+09:00
Subject: Re: Comparing Proc Objects?

On 11/14/05, Daniel Schierbeck <daniel.schierbeck@gmail.com> wrote:
> What I'm interested in
> knowing is how I check whether any supplied block matches the one from
> the cached call.

I think the only way you're going to get equality with a supplied
block is if it is an object, i.e. created with proc or Proc.new or by
passing through another method. Every other form is generated on the
fly AFAIK.

Regards,

Sean

P.S. This is what I used to test this:

require 'pp'

@blocks = Hash.new(0)

def count_block(&block)
  @blocks[block] += 1
end

def make_block(&block)
  block
end

def test_method(x)
  x + 1
end

block = proc {|x| x + 1}
block2 = Proc.new do |x| x + 1 end

count_block &block
count_block &block
count_block &block2
count_block &block2
count_block do |x| x + 1 end
count_block do |x| x + 1 end
count_block { |x| x + 1 }
count_block { |x| x + 1 }
count_block &make_block { |x| x + 1 }

count_block &method(:test_method)
count_block &method(:test_method)
meth = method(:test_method)
count_block &meth
count_block &meth

meth2 = Proc.new &method(:test_method)
count_block &meth2
count_block &meth2

pp @blocks
__END__
---------- OUTPUT ----------
{#<Proc:0x02db4de8@C:/rubylib/experiments/ruby-talk/compare-blocks.rb:33>=>1,
 #<Proc:0x028710f8@C:/rubylib/experiments/ruby-talk/compare-blocks.rb:20>=>2,
 #<Proc:0x02871278@C:/rubylib/experiments/ruby-talk/compare-blocks.rb:19>=>2,
 #<Proc:0x02db4d28@C:/rubylib/experiments/ruby-talk/compare-blocks.rb:38>=>2,
 #<Proc:0x02db4e30@C:/rubylib/experiments/ruby-talk/compare-blocks.rb:32>=>1,
 #<Proc:0x028708a0@C:/rubylib/experiments/ruby-talk/compare-blocks.rb:30>=>1,
 #<Proc:0x02db4d70@C:/rubylib/experiments/ruby-talk/compare-blocks.rb:36>=>1,
 #<Proc:0x028709d8@C:/rubylib/experiments/ruby-talk/compare-blocks.rb:29>=>1,
 #<Proc:0x02870b10@C:/rubylib/experiments/ruby-talk/compare-blocks.rb:28>=>1,
 #<Proc:0x02db4da0@C:/rubylib/experiments/ruby-talk/compare-blocks.rb:35>=>1,
 #<Proc:0x02870c48@C:/rubylib/experiments/ruby-talk/compare-blocks.rb:27>=>1,
 #<Proc:0x02870d80@C:/rubylib/experiments/ruby-talk/compare-blocks.rb:26>=>1}