RCR debug

Hi list

this is incredibly simple, but I just wanted to know what you think about it.

I really often write the following code

puts <whatever> if $DEBUG

I guess you all do that to some extent, James just talked a newbie
into it recently :wink:

The first programmer's virtue of course makes me do some things like
def debug *args, &blk
聽聽聽return unless $DEBUG
聽聽<do something incredibly smart with the args ;)>
end
and sometimes on some of my machines I will do something like

require 'ilmig/tools/debug'

I feel that this might be so common place that a Kernel::debug or
whatever other suitable name might be a good idea.

I am listening .... :wink:

Cheers
Robert

路路路

--
You see things; and you say Why?
But I dream things that never were; and I say Why not?
-- George Bernard Shaw

For medium to large programs having a global $DEBUG flag is going to
create lots of "line noise" as all those debug messages go whipping
by.

I much prefer the fine grained control that the 'logging' and 'log4r'
packages give you.

require 'logging'

class A
聽聽def initialize
聽聽聽聽@log = Logging::Logger[self]
聽聽聽聽@log.debug "new object created '#{self.object_id}'"
聽聽end
end

class B
聽聽def initialize
聽聽聽聽@log = Logging::Logger[self]
聽聽聽聽@log.debug "new object created '#{self.object_id}'"
聽聽end
end

Logging::Logger['A'].level = :warn
Logging::Logger['B'].level = :debug

It's a little more setup, but you have far greater control over what
gets logged and what doesn't. The framework also takes care of
timestamps, outputting class info, etc.

And if you don't want all that complexity, there is always the core
Logger class that comes with Ruby.

Blessings,
TwP

路路路

On 4/13/07, Robert Dober <robert.dober@gmail.com> wrote:

Hi list

this is incredibly simple, but I just wanted to know what you think about it.

I really often write the following code

puts <whatever> if $DEBUG

I guess you all do that to some extent, James just talked a newbie
into it recently :wink:

The first programmer's virtue of course makes me do some things like
def debug *args, &blk
聽聽聽return unless $DEBUG
聽聽<do something incredibly smart with the args ;)>
end
and sometimes on some of my machines I will do something like

require 'ilmig/tools/debug'

I feel that this might be so common place that a Kernel::debug or
whatever other suitable name might be a good idea.

I am listening .... :wink:

> Hi list
>
> this is incredibly simple, but I just wanted to know what you think about it.
>
> I really often write the following code
>
> puts <whatever> if $DEBUG
>
> I guess you all do that to some extent, James just talked a newbie
> into it recently :wink:
>
> The first programmer's virtue of course makes me do some things like
> def debug *args, &blk
> return unless $DEBUG
> <do something incredibly smart with the args ;)>
> end
> and sometimes on some of my machines I will do something like
>
> require 'ilmig/tools/debug'
>
> I feel that this might be so common place that a Kernel::debug or
> whatever other suitable name might be a good idea.
>
> I am listening .... :wink:
>

For medium to large programs having a global $DEBUG flag is going to
create lots of "line noise" as all those debug messages go whipping
by.

Tim the $DEBUG mechanism is quite primitive and other things are
needed for large scale development, no doubt.
My idea of the CR is orbiting around $DEBUG which is widely used in
quick hacks or small to medium scale development, but...

I much prefer the fine grained control that the 'logging' and 'log4r'
packages give you.

require 'logging'

class A
聽聽def initialize
聽聽聽聽@log = Logging::Logger[self]
聽聽聽聽@log.debug "new object created '#{self.object_id}'"
聽聽end
end

class B
聽聽def initialize
聽聽聽聽@log = Logging::Logger[self]
聽聽聽聽@log.debug "new object created '#{self.object_id}'"
聽聽end
end

Logging::Logger['A'].level = :warn
Logging::Logger['B'].level = :debug

It's a little more setup, but you have far greater control over what
gets logged and what doesn't. The framework also takes care of
timestamps, outputting class info, etc.

And if you don't want all that complexity, there is always the core
Logger class that comes with Ruby.

Blessings,
TwP

... I take one idea from your mail, with your kind permission :wink:

Why not enhancing the semantics of $DEBUG at the same moment, I will elaborate

路路路

On 4/13/07, Tim Pease <tim.pease@gmail.com> wrote:

On 4/13/07, Robert Dober <robert.dober@gmail.com> wrote:

-----------------------------------------------------------------------------------
def Kernel.debug *args, &blk
聽聽聽return unless $DEBUG
聽聽聽begin
聽聽聽聽聽聽$DEBUG.puts args.join(" ") unless args.empty?
聽聽聽聽聽聽blk.call $DEBUG if blk
聽聽聽rescue
聽聽聽聽聽聽warn $DEBUG does not respond to the #puts message
聽聽聽end
end

now you can write code like

debug "OMG this should be deadcode, why I am here, I just kept that
code for sentimental reasons!!!!"

or
debug do
聽聽聽puts "whatever"
end

or

debug {
聽聽聽> stream |
聽聽聽stream.puts "@inst = #{@inst}"
}

or
debug do
聽聽$DEBUG.print "one"
end

of course the -d switch of ruby would just set $DEBUG to $stdout,
maybe a -l <stream>
switch could be introduced to set $DEBUG to a writeable IO object
representing <stream>
------------------------------------------------------------------------------------------------------

Now I realize I did not think about other debugging mechanisms, the
core idea is just to simplify what I think is a common and useful
idiom namely
聽聽puts "/...." if $DEBUG

I do not think that this will compete with more advanced debugging,
logging features, but why not enhance the $DEBUG switch as suggested
above.

Yeah and before I forget, thx for your input Tim.

Cheers
Robert

--
You see things; and you say Why?
But I dream things that never were; and I say Why not?
-- George Bernard Shaw

A simple debug method seems like a great idea. But what happens when
it ends up in Kernel and everyone starts using it? Now you'll get all
the debug messages from your code and all the library code that you
include. That's why I don't like the $DEBUG option.

I know you want to put it into Kernel so everyone can use. But that's
the whole problem -- everyone will start using it! And then it
becomes not so useful.

This is similar to making sure that your code runs -w clean (i.e.
won't throw out warnings). The rails core is very bad about this --
lot's of warnings. Now you cannot find the warnings in your own code
because all the rails warnings are cluttering things up.

Same problem with a global $DEBUG flag.

Just my $0.02 on the matter.

Blessings,
TwP

PS Why not include this in the facets library? I think this would be
a much more suitable place for such a creature.

<http://facets.rubyforge.org/>

路路路

On 4/13/07, Robert Dober <robert.dober@gmail.com> wrote:

Tim the $DEBUG mechanism is quite primitive and other things are
needed for large scale development, no doubt.
My idea of the CR is orbiting around $DEBUG which is widely used in
quick hacks or small to medium scale development, but...

alternatively

聽聽聽logger = Logger.new STDERR
聽聽聽logger.level = ENV['DEBUG_ENV_FOR_MY_CODE'] ? Logger::DEBUG : LOGGER::INFO

聽聽聽logger.debug{ 'now you have a debug method that can be turned on/off from the environment' }

it's prety kiss...

-a

路路路

On Sat, 14 Apr 2007, Tim Pease wrote:

On 4/13/07, Robert Dober <robert.dober@gmail.com> wrote:

Tim the $DEBUG mechanism is quite primitive and other things are
needed for large scale development, no doubt.
My idea of the CR is orbiting around $DEBUG which is widely used in
quick hacks or small to medium scale development, but...

A simple debug method seems like a great idea. But what happens when
it ends up in Kernel and everyone starts using it? Now you'll get all
the debug messages from your code and all the library code that you
include. That's why I don't like the $DEBUG option.

I know you want to put it into Kernel so everyone can use. But that's
the whole problem -- everyone will start using it! And then it
becomes not so useful.

This is similar to making sure that your code runs -w clean (i.e.
won't throw out warnings). The rails core is very bad about this --
lot's of warnings. Now you cannot find the warnings in your own code
because all the rails warnings are cluttering things up.

Same problem with a global $DEBUG flag.

Just my $0.02 on the matter.

Blessings,
TwP

PS Why not include this in the facets library? I think this would be
a much more suitable place for such a creature.

<http://facets.rubyforge.org/>

--
be kind whenever possible... it is always possible.
- the dalai lama

Ara I guess you are right about the Kernel, a standard library
module/class might be better, voici Logger.
Funnily I think I really have not done enough research about Logger
after Tim's input, well maybe because Tim just explained that he
prefered Logger and that was not on my mind.
Sorry Tim if I was not thoughtful enough.
I feel that I just wanted to facilitate a common pattern, I had not
though a second about if that common pattern was worth being
facilitated...
... probably it is not.
Thanks for your input, I guess I'll call it an RCR ;).

This is a great ML, they think for you, someone to write a solution
for this weeks Ruby Quiz for me ? :)))

Cheers
Robert

路路路

On 4/14/07, ara.t.howard@noaa.gov <ara.t.howard@noaa.gov> wrote:

On Sat, 14 Apr 2007, Tim Pease wrote:

> On 4/13/07, Robert Dober <robert.dober@gmail.com> wrote:
>> Tim the $DEBUG mechanism is quite primitive and other things are
>> needed for large scale development, no doubt.
>> My idea of the CR is orbiting around $DEBUG which is widely used in
>> quick hacks or small to medium scale development, but...
>
> A simple debug method seems like a great idea. But what happens when
> it ends up in Kernel and everyone starts using it? Now you'll get all
> the debug messages from your code and all the library code that you
> include. That's why I don't like the $DEBUG option.
>
> I know you want to put it into Kernel so everyone can use. But that's
> the whole problem -- everyone will start using it! And then it
> becomes not so useful.
>
> This is similar to making sure that your code runs -w clean (i.e.
> won't throw out warnings). The rails core is very bad about this --
> lot's of warnings. Now you cannot find the warnings in your own code
> because all the rails warnings are cluttering things up.
>
> Same problem with a global $DEBUG flag.
>
> Just my $0.02 on the matter.
>
> Blessings,
> TwP
>
> PS Why not include this in the facets library? I think this would be
> a much more suitable place for such a creature.
>
> <http://facets.rubyforge.org/>

alternatively

聽聽聽logger = Logger.new STDERR
聽聽聽logger.level = ENV['DEBUG_ENV_FOR_MY_CODE'] ? Logger::DEBUG : LOGGER::INFO

聽聽聽logger.debug{ 'now you have a debug method that can be turned on/off from the environment' }

it's prety kiss...

-a
--
be kind whenever possible... it is always possible.
- the dalai lama

--
You see things; and you say Why?
But I dream things that never were; and I say Why not?
-- George Bernard Shaw