From: Yukihiro Matsumoto <matz@...>
Date: 2009-07-21T01:49:09+09:00
Subject: [ruby-core:24461] Re: lvar_propagate

Hi,

In message "Re: [ruby-core:24435] Re: lvar_propagate"
    on Sun, 19 Jul 2009 05:27:31 +0900, Laurent Sansonetti <laurent.sansonetti@gmail.com> writes:

|I am a bit confused. What would the following snippets do if lvar
|propagation is implemented?
|
|# Snippet1
|0.times { x = 42 } # never called
|x # nil or NameError?

Scope propagation happens in compile time, so calling (or not) do not
affect the scope, so x will be nil.

|# Snippet2
|def foo
|  proc { x = 42 } # created but called later
|end
|def bar
|  foo.call
|  x # 42 or NameError?
|end
|bar

Propagation will not happen across normal local variable scope
(i.e. def/class/module), so x in bar has no chance to be declared as a
local variable, thus NameError.

							matz.