From: Robert Klemme <bob.news@...>
Date: 2006-03-01T00:58:36+09:00
Subject: Re: Same variable name used in block and local question

dblack@wobblini.net wrote:
> Hi --
>
> On Tue, 28 Feb 2006, Robert Klemme wrote:
>
>> rubyrus wrote:
>>> Can anybody help me here, TIA!!
>>>
>>> This is the code.  I expect to see the string "Afterward:turkey",
>>> but why am I getting "Afterward:camel"?  |animal| parameter in a
>>> block should be temporary inside the block, right??
>>
>> No, it isn't because it was defined outside the block.  It's used in
>> cases like
>>
>> count = 0
>> arr.each { count += 1 }
>> puts "count=#{count}"
>>
>> If you want to keep it local you must not define it in the
>> surrounding scope.
>
> I think that's a different thing, though, from the parameter
> semantics.  As I understand it, in 2.0 things would work like this:

Is there a difference with regard to scope between

(1..10).each {|foo| }

and

(1..10).each { foo = 1 }

?  I think in both cases foo is limited to the block:

16:51:56 [~]: ruby -e 'def f() (1..5).each {|foo|}; foo end; f'
-e:1:in `f': undefined local variable or method `foo' for main:Object
(NameError)
        from -e:1
16:51:59 [~]: ruby -e 'def f() (1..5).each {foo=1}; foo end; f'
-e:1:in `f': undefined local variable or method `foo' for main:Object
(NameError)
        from -e:1
16:52:04 [~]:

Note, I'm not talking about Ruby 2.

>    count = 0
>    other = "zero"
>    [1,2,3].each {|other| count += 1 }
>
>    # count is now 3
>    # other is still "zero"
>
> I may be getting it wrong... but I think the scoping of parameter
> variables and other block variables is going to diverge.

That's why I stick to the status quo - I lost track of this discussion
somewhere.  But I trust Matz to do it properly.  At least all relevant
arguments seem to have been exchanged.  :-)

Kind regards

    robert