From: Mathieu Bouchard <matju@...>
Date: 2002-01-21T03:06:15+09:00
Subject: Re: $_ as default parameter for a function


On Sun, 20 Jan 2002, Thomas wrote:

> Mathieu Bouchard <matju@sympatico.ca> wrote in message
> > 			set_trace_func(proc{|*a|
> > 				w.puts(eval("$_", a[4]).inspect)
> I'd expect a significant performance penalty for the code above. Any
> ideas about how expensive the code above is?

Most of the performance penalty should be in the call to fork(), even on
fast-forking kernels like Linux.

Anyway, I didn't write that code to see it used, but rather to tell that
either using $_ is wrong, or Ruby lacks a feature or two. See also RCR
#29:

	http://www.rubygarden.org/article.php?sid=89

in that case you would be able to look it up like
eval("$_",binding.caller), which would be quite fast.

________________________________________________________________
Mathieu Bouchard                   http://hostname.2y.net/~matju