From: matz@... (Yukihiro Matsumoto)
Date: 2003-02-13T09:42:03+09:00
Subject: Re: Lexical scope and closures

Hi,

In message "Re: Lexical scope and closures"
    on 03/02/13, "Hal E. Fulton" <hal9000@hypermetrics.com> writes:

|What happens to the case where obj has a meth= method, and
|we put obj.meth between vertical bars?

This will cause warning first, then eventually become error in the far
future version.  Block parameters will be more like method arguments.

|And how will I save the value of an iterated variable? Will I have
|to assign it to a var in the outer scope as soon as I enter the
|block?

You have to assign to a variable from a block parameter.

|> It will also break old code where it depends on a variable introduced in a
|> block being local, e.g.
|>
|>    Thread.new {
|>      i = 0
|>      ... use i locally
|>    }
|>
|> I don't remember seeing a warning for this situation being discussed, but
|it
|> would seem logical to do so.
|
|Hmm, even more confusing. But perhaps you could simply add
|your block-local variable(s) to the list:  Thread.new {|i|...

Yes, it's possible, even now.

|It seems that Matz's INVIOLABLE rule is to keep Ruby
|declarationless. Every solution I saw (I think) that
|kept all functionality involved some kind of declaration
|mechanism.

Yes, for variable declarations.  But I'm always open for new ideas.

							matz.