Hi all,
Liz and Tux demonstrate powerful Perl6 code at each monthly meeting of
our Mongers in Amsterdam. Looking at their examples, I collected a few
questions of which I want to discuss the first one in this thread.
When I look at Merijns (Tux') code, I see a huge number of :D attributes.
https://github.com/Tux/CSV/blob/master/lib/Text/CSV.pm
Close to all scalar positional parameter (51x) carry the :D flag. I count
only 3 where the parameter does accept undef and the method is able to
handle it. I count another 3 where the :D is missing, but the method is
not able the handle it.
The same for examples Liz shows us in our core code: most scalar
positional parameters have :D.
Writing a sub which is able to handle undef is usually more work than
implementing "I expect sane values for all of the parameters".
Questions:
. are they using :D correctly?
. the simpelest code does not handle the undef case... but now needs
the more complex prototype to be correct.
. it feels like the wrong default: usually you have to do something
extra for the unusual cases, not the 90%+ usual cases.
. :D looks really ugly, don't you think? Try to explain to students
to add this smiley everywhere.
Can someone explain this to me? (Or point me to the correct place)
--
Thanks in advance
MarkOv
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Mark Overmeer MSc MARKOV Solutions
[email protected] [email protected]
http://Mark.Overmeer.net http://solutions.overmeer.net
