From: Morton Goldberg <m_goldberg@...>
Date: 2006-08-02T23:02:54+09:00
Subject: Re: Different semantics of Proc and method call -- bug or feature?

This _is_ strange. R. Klemme's explanation is enlightening, but now I  
wonder why qq in the following works like a method definition rather  
than like pp?

#! /usr/bin/ruby -w

pp = Proc.new do |arg, *args|
    p [arg, args]
end

qq = lambda do |arg, *args|
    p [arg, args]
end

s = 1
v = [2]

puts VERSION => 1.8.2

pp.call s => [1, []]
pp.call v => [2, []]
pp.call v, v => [[2], [[2]]]

qq.call s => [1, []]
qq.call v => [[2], []]
qq.call v, v => [[2], [[2]]]

Regards, Morton

On Aug 2, 2006, at 8:35 AM, Tammo Freese wrote:

> Hi all,
>
>
> I stumbled over the following difference between method calls and  
> Proc calls:
>
> require 'pp';
>
> def a_method(arg, *args)
>   arg
> end
>
> a_proc = Proc.new do | arg, *args |
>   arg
> end
>
> pp a_method(1)       # => expected 1, got 1
> pp a_proc.call(1)    # => expected 1, got 1
>
> pp a_method([1])     # => expected [1], got [1]
> pp a_proc.call([1])  # => expected [1], got 1     <== ?!
>
>
> I would expect that method calls and proc calls do not differ in  
> such a way.
> Is this a bug or a feature?
>
>
> Thanks for your help,
>
> Tammo
>