From: Gavin Kistner <gavin@...>
Date: 2005-06-30T23:37:08+09:00
Subject: ruby -dn; levels for $DEBUG

I would find it convenient if:
    ruby -d foo.rb
set $DEBUG to true, while
   ruby -d1 foo.rb
set $DEBUG to 1
   ruby -d3 foo.rb
set $DEBUG to 3, and possibly even
   ruby -dALL foo.rb
set $DEBUG to "ALL". (I'm willing to give up that last, though.)

This would break any existing code that did something silly like:
    if $DEBUG == true
instead of
   if $DEBUG
but would provide the ability to set verbosity level for debugging.

In debugging JavaScript in HTML, I wrote my own DebugOut function  
which took a string and a verbosity level, and by changing one  
numeric at the top of the file could easily see more or less verbose  
traces of the code execution. It's a poor substitute for a debugging  
IDE, but at the same time quite helpful.

What do people think?