From: "Peña, Botp" <botp@...>
Date: 2008-04-16T10:03:59+09:00
Subject: Re: Annoying block variable behaviour !!

From: Iñaki Baz Castillo [mailto:ibc@aliax.net] 
# but in b) is annoying, kk is finally "true" just because in a 
# block it was "true" and before it it was defined in top level.
# IMHO it makes no sense at all. Is there any explanation for 
# this last case?

the ruby community is divided when it comes to this shadowing behaviour of block locals and block params. see the ruby archives.

on your case, ruby1.9 may satisfy

irb(main):005:0* RUBY_VERSION
=> "1.9.0"
irb(main):006:0> [1,2,3,4].each { |kk| kk=true }
=> [1, 2, 3, 4]
irb(main):007:0> kk
NameError: undefined local variable or method `kk' for main:Object

irb(main):008:0> kk=false
=> false
irb(main):009:0> [1,2,3,4].each { |kk| kk=true }
=> [1, 2, 3, 4]
irb(main):010:0> kk
=> false

and it comes w warnings too just in case you want to be safe ;)

C:\ruby1.9\bin>ruby1.9 -we "kk=false; [1,2,3,4].each { |kk| kk=true } "
-e:1: warning: shadowing outer local variable - kk

kind regards -botp