$stderr debugging library

ruby-talk
1

I've got a library I use for writing temporary debug output to $stderr. Why $stderr? Because I work with command-line programs that employ a lot of stdout redirection; I want the debug output to be visible on the console rather than redirected along with the program's $stdout.

Q: What's the prior art? Does some gem already do any of what this library does?
Q: It this generally useful? That is, does anyone else debug by writing to the console?
Q: What would be a good name for it, if published as a gem?

Features include:

* Writes to $stderr instead of $stdout
* Can automatically print filename and line number
* Can automatically label the values being output
* Can easily inspect the middle of a call chain

Details:

Kernel#q is like Kernel#p, except that it writes to $stderr.

Kernel#qq is like Kernel#pp from the 'pp' library, except that it writes to $stderr.

Kernel#ql is like Kernel#q, but it also outputs the file/line from which it was called:

     ql "foo" # writes: test.rb:8: "foo"

* Output can be automatically labeled:

     foo = 1
     bar = 2
     q {'foo + bar'} # writes: foo + bar = 3
     ql {:bar} # writes: foo.rb:9: bar = 2

Kernel#tapq makes it easy to examine the middle of a call chain:

     ['1', '2'].map(&:to_i).tapq.map(&:even?) # writes: [1, 2]

Best Regards,
Wayne Conrad

2

Obviously: q

See also "d" and "g"

···

On Aug 28, 2014, at 11:29 AM, Wayne Conrad <kf7qga@gmail.com> wrote:

Q: What would be a good name for it, if published as a gem?

3

Very helpful, thanks! The way the "wrong" gem's #d method is parsing the source is superior to my cheesy eval-the-string approach. I will be borrowing from that gem.

Unfortunately, there is already a "q" gem. For now, I'm using the name "print_debug." It's not a great name. It just stinks less than the other names I've come up with.

Regards,
Wayne Conrad

···

On 08/28/2014 08:43 AM, Alex Chaffee wrote:

On Aug 28, 2014, at 11:29 AM, Wayne Conrad <kf7qga@gmail.com > <mailto:kf7qga@gmail.com>> wrote:

Q: What would be a good name for it, if published as a gem?

Obviously: q

See also "d" and "g"

wrong/README.markdown at master · alexch/wrong · GitHub

GitHub - jugyo/g: The Kernel.g that works like Kernel.p by using terminal-notifier or growl.

4

Sounds like a useful gem.

···

On 14-08-29, 6:55, Wayne Conrad wrote:

Unfortunately, there is already a "q" gem. For now, I'm using the name
"print_debug." It's not a great name. It just stinks less than the
other names I've come up with.

How about "cute_print": synonymous with "pretty", and sounds like "q".

Andrew Vit

5

how about $stddebug?

···

On Fri, Aug 29, 2014 at 10:22 PM, Andrew Vit <andrew@avit.ca> wrote:

Sounds like a useful gem.

On 14-08-29, 6:55, Wayne Conrad wrote:

Unfortunately, there is already a "q" gem. For now, I'm using the name
"print_debug." It's not a great name. It just stinks less than the
other names I've come up with.

How about "cute_print": synonymous with "pretty", and sounds like "q".

Andrew Vit

6

Adam, Andrew, and Alex (the A team!), thank you for your help. I liked Andrew's suggestion best:

     http://rubygems.org/gems/cute_print

Regards,
Wayne Conrad