From: Robert Klemme <bob.news@...>
Date: 2004-02-26T22:49:48+09:00
Subject: Re: proposal: debug keyword

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"Simon Strandgaard" <neoneye@adslhome.dk> schrieb im Newsbeitrag
news:pan.2004.02.26.13.08.27.945491@adslhome.dk...
> On Wed, 25 Feb 2004 13:16:50 +0100, Simon Strandgaard wrote:
> [snip]
> > I think this would be a good idea to have distributed with Ruby?
> > I am thinking of submitting an RCR, should I do this?
> >
>
> Question still stands, should I make an RCR out of it?
>
>
> Consideration if the name 'debug' is ok?

When switching debugging for certain methods "debug_method" is more
appropriate IMHO. "debug" implies some global thingy.  My 0.02 EUR...

> Temporary enabling a global flag is more general,
> perhaps its better to make a temporary-set method
>
> temp_set $global_variable, :method
>
> Instead of naming it 'debug', then maybe name it
>
> temp_set_debug :method
>
>
> What should be in the RCR?
> the 'temp_set' thing  or the  'debug' keyword thing?
>
>
> Sorry for rambling.. needs more input ;-)

Hm...  Just as food for thought: how about some more aspect oriented
solution, i.e., debug aspects to switch on and off (see attachment).

Regards

    robert



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#!/usr/bin/ruby

module Kernel
  def debug_on(*aspects)
    Kernel.debug_switch(true, aspects)
  end

  def debug_off(*aspects)
    Kernel.debug_switch(false, aspects)
  end

  def debug(aspect)
    yield if Kernel.debug? aspect
  end

  class <<self
    def debug_switch(flag, aspects)
      if aspects.empty?
        Kernel.debug_global flag
      else
        Kernel.debug_local(flag, aspects)
      end
    end

    def debug_local(flag, aspects)
      d = (@debugs ||= {})
      aspects.each {|a| d[a]=flag}
    end

    def debug_global(flag)
      @debugs.keys.each {|a| @debugs[a]=flag} if @debugs
    end

    def debug?(aspect)
      @debugs && @debugs[aspect]
    end
  end
end


class Foo
  def bar
    debug :event do $stderr.puts "entering method" end
    puts "before"
    debug :all  do $stderr.puts "Debug message for all" end
    puts "after"
    debug :event do $stderr.puts "leaving method" end
  end
end


f = Foo.new

f.bar
debug_on :event
f.bar
debug_on :all
f.bar
debug_off :event
f.bar
debug_off
f.bar
debug_on
f.bar
debug_off
f.bar


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