From: Robert Klemme <bob.news@...>
Date: 2006-03-27T22:23:55+09:00
Subject: Re: scope issue of variable in iterator

Mauricio Fernandez wrote:
> On Mon, Mar 27, 2006 at 04:23:54PM +0900, Robert Klemme wrote:
>> Mohammad Khan wrote:
>>> When I am writing
>>> array.each do | blah | end
>>>
>>> It would be really convenient if blah is scopped only in this iterator
>>> block, regardless of blah decleared before or not.
>> You wouldn't be able to do things like this:
>>
>> sum = 0
>> enum.each {|item| sum += item}
> 
> Not really; item being block-scoped wouldn't preclude access to other local
> variables.

Right.  Apparently I wasn't fully awake when I wrote that.

 > What you wouldn't be able to do is:
> 
> def set_get
>   a = nil
>   [lambda{|a|}, lambda{a}]
> end
> set, get = set_get
> set[1]
> get[]                                              # => 1
> 
> forcing you to go this way:
>   [lambda{|b| a = b}, lambda{a}]

Seems like a rare thing to do.  This is another thing you cannot do with 
the proposed change:

last = nil
enum.each {|last|}
puts "last was #{last}"

Although you can of course with #inject.

Kind regards

	robert