On Fri, Sep 14, 2012 at 3:47 AM, Shlomi Fish shlo...@shlomifish.org wrote:
On Thu, 13 Sep 2012 19:40:53 -0400
Rocky Bernstein rocky.bernst...@gmail.com wrote:
http://perldoc.perl.org/DB.html mentions a programmatic interface to
the Perl debugging API.
As far as I can tell it hasn't really changed at all since Perl 5.8
and not much between that and 5.6 except bug fixes. Why was this not
more widely adopted?
I guess not too many people need to write custom debuggers.
I am weary of arguments of the form because if X isn't used much something
that X attempts to address is not needed by too many people.
First, from what I've seen there have been a number of custom debuggers
including a large number of customization of perl5db: for remote execution
or handling syntax highlighting. I just became aware of a recent YAPC paper
on trying to automatically figure out when an input line in perl5db is not
finished so as to offer another read rather than eval the line.
And consider dtrace which is popular. From what I understand, that is used
for custom tracing which to me amounts to the same thing as debugging.
dtrace doesn't sport a REPL although one could probably add that into the
Now back to the DB module. Although it may appear to advertise itself as
for writing REPL debuggers, it doesn't have to be used that way. So perhaps
the DB API module was not advertising itself in not the most encompassing
One of the ideas that I think is right about the DB module is the fact that
programs can register for a callback. Supposedly DB handles all of the
lower-level boilerplate DB module stuff.
One might imagine registering a callback when various events occur to be
something that should be put in the Perl core, but since all of this code
can be written in Perl (as evidence by the DB module), why then put it in
the Perl core?
And finally coming back to the original question, I was hoping that someone
who was working on perl5db at the time could elaborate on what specifically
happened here, rather than speculatively what might have happened.
seems that many Perl developers avoid using the debugger in favour of print
statements and other stuff like that.
Shlomi Fish http://www.shlomifish.org/
What Makes Software Apps High Quality - http://shlom.in/sw-quality
Quark: “Too much of a good thing is a bad thing. But only for your
Rule of acquisition No. 172.
— Star Trek, “We, the Living Dead” by Shlomi Fish
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