r-lib/debugme

use a filter to select debugging by level like Smart::Comment do

kforner opened this issue · 5 comments

kforner commented

Hi Gabor,

I have just discovered your package and I am already a big fan !
Do you know the Smart::Comment perl package ?
It uses the same kind of approach, using comments instead of string litterals (which you can not since R discards them in parsed code).

You set the level of the debugging by the number of '#', eg.
### is a level 1 debug
#### is a level2 debug
and you can select the debugging level at execution time using the Smart_Comment env var, e.g.
Smart_Comment=###:#### ./my_script.pl
which I think is nice since when you want to debug a script, you do not a priori know which packages it uses (can be indirect), so selecting the package via DEBUGME might not be the most convenient approach.

Maybe the syntax could be expanded like this:
DEBUGME=mypkg : turns on debugging for mypkg
DEBUGME=mypkg:1 turns on debugging level 1 for mypkg
DEBUGME=mypkg1:1,mypkg2:3
DEBUGME=1 turns on debugging level 1 for all packages

What do you think ?

Karl

gaborcsardi commented

I have just discovered your package and I am already a big fan !

Thanks!

Do you know the Smart::Comment perl package ?
It uses the same kind of approach, using comments instead of string litterals (which you can not since R discards them in parsed code).

Yeah, that's why I am using string literals.

You set the level of the debugging by the number of '#', eg.
### is a level 1 debug
#### is a level2 debug
and you can select the debugging level at execution time using the Smart_Comment env var, e.g.
Smart_Comment=###:#### ./my_script.pl
which I think is nice since when you want to debug a script, you do not a priori know which packages it uses (can be indirect), so selecting the package via DEBUG_ME might not be the most convenient approach.
What do you think ?

I thinks these are great ideas! AFAICT there are two possible improvements that we could make. One is setting the debug level of the messages, the way you propose. I would you exclamation marks, so that it is compatible with the current syntax:

"!DEBUG level 1"
...
"!!DEBUG level 2"
etc.

The other is auto-debugging. TBH I am not sure if this is useful enough in practice, because most packages do not use debugme. But I can imagine two improvements for it:

  • setting DEBUGME="all" would debug all packages (that support debugme, obviously). Maybe we can also have an "all packages except these" syntax.
  • adding a function that queries which packages use debugme, so you'll have a rough idea what kind of messages to expect.

What do you think?

kforner commented

[I've updated my previous post]

I agree with the ! to indicate the debugging level.

as I wrote, maybe just DEBUGME=":1" to turn on debugging level 1 for all packages ?

gaborcsardi commented

Cool. Yeah, basically we just need to work out a good syntax now. I see your point about DEBUGME=":1". I like the explicit DEBUGME="all" as well. So how about sg like this:

DEBUGME="pkg1,pkg2"
DEBUGME="!!pkg1,pkg2"
DEBUGME="all"
DEBUGME="!!!all"
DEBUGME="all,-except1,-except2"
DEBUGME="!!!all,-except1"
kforner commented

looks good !

gaborcsardi commented

OK, log levels are now supported. all and the -package notation are not yet. I'll open separate issues for those.

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