From: Robert Klemme <bob.news@...>
Date: 2003-06-24T03:59:44+09:00
Subject: Block Scope Statement in the Pickaxe


Hi,

I stumbled across this quote in chapter 15, "Ruby Tk", which confused me a
bit:

"One small caution when using the code block form: the scope of variables is
not what you think it is. The block is actually evaluated in the context of
the widget's object, not the caller's. This means that the caller's instance
variables will not be available in the block, but local variables from the
enclosing scope and globals (not that you ever use those) will be."

How can this be?  I mean, AFAIK the block's binding refers to client code
and cannot be changed afterwards.  Or did I miss something?  Is this some
kind of implementation trick that can be done with a Ruby extension?

Thanks for an explanation.

Regards

    robert