[Bioperl-l] For CVS developers - potential pitfallwith "returnundef"

[Heikki Lehvaslaiho]

In my opinion the sooner the bugs get exposed the better. It is much more 
likely that there is a well hidden bug caused by assigning accidentally undef 
into an one element array that someone intentionally writing code that 
expects that behaviour!

I removed (but did not commit yet) all undefs from my old Bio::Variation code 
and could not see any differences in the test output. 

Let's remove them!

	-Heikki

On Tuesday 30 May 2006 23:40, Chris Fields wrote:
> Agreed, though I think these changes should be implemented at some point
> (Conway's argument here makes sense and it is nice for Torsten to check
> this out).  If proper tests are written then any changes resulting in
> errors should be picked up by checking the appropriate test suite, though I
> know it doesn't absolutely guarantee it.  ; P
>
> Chris
>
> > -----Original Message-----
> > From: bioperl-l-bounces at lists.open-bio.org [mailto:bioperl-l-
> > bounces at lists.open-bio.org] On Behalf Of Rutger Vos
> > Sent: Tuesday, May 30, 2006 1:53 PM
> > To: bioperl-l at lists.open-bio.org
> > Subject: Re: [Bioperl-l] For CVS developers - potential pitfallwith
> > "returnundef"
> >
> > Although I agree with the sentiment of following PBP, I'm not so sure
> > changing 'return undef' to 'return' *now* will fix any bugs without
> > introducing new, subtle ones.
> >
> > Chris Fields wrote:
> > > Torsten,
> > >
> > > Any way you can post a list of some/all of the offending lines or
> >
> > modules?
> >
> > > Sounds like something to consider, but if the list is as large as you
> >
> > say we
> >
> > > made need something (bugzilla? wiki?) to track the changes and make
> > > sure they pass tests; I'm sure a large majority will.
> > >
> > > I'm guessing Jason would want this somewhere on the project priority
> >
> > list or
> >
> > > bugzilla, with a link to the actual list, but I'm not sure.  Maybe
> > > start
> >
> > a
> >
> > > page on the wiki for proposed code changes?
> > >
> > > Chris
> > >
> > >> -----Original Message-----
> > >> From: bioperl-l-bounces at lists.open-bio.org [mailto:bioperl-l-
> > >> bounces at lists.open-bio.org] On Behalf Of Torsten Seemann
> > >> Sent: Tuesday, May 30, 2006 3:19 AM
> > >> To: bioperl-l at lists.open-bio.org
> > >> Subject: [Bioperl-l] For CVS developers - potential pitfall with
> > >> "returnundef"
> > >>
> > >> FYI Bioperl developers:
> > >>
> > >> I just audited the bioperl-live CVS and found about 450 occurrences of
> > >> "return undef".
> > >>
> > >> Page 199 of "Perl Best Practices" by Damian Conway, and this URL
> > >> http://www.perl.com/lpt/a/2006/02/23/advanced_subroutines.html
> > >> suggest:
> > >>
> > >> "Use return; instead of return undef; if you want to return nothing.
> > >> If someone assigns the return value to an array, the latter creates an
> > >> array of one value (undef), which evaluates to true. The former will
> > >> correctly handle all contexts."
> > >>
> > >> So I'm guessing at least some of these 450 occurrences *could* result
> >
> > in
> >
> > >> bugs and should probably be changed.
> > >>
> > >> Your opinion may differ :-)
> > >>
> > >> --
> > >> Dr Torsten Seemann               http://www.vicbioinformatics.com
> > >> Victorian Bioinformatics Consortium, Monash University, Australia
> > >>
> > >> _______________________________________________
> > >> Bioperl-l mailing list
> > >> Bioperl-l at lists.open-bio.org
> > >> http://lists.open-bio.org/mailman/listinfo/bioperl-l
> > >
> > > _______________________________________________
> > > Bioperl-l mailing list
> > > Bioperl-l at lists.open-bio.org
> > > http://lists.open-bio.org/mailman/listinfo/bioperl-l
> >
> > --
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++
> > Rutger Vos, PhD. candidate
> > Department of Biological Sciences
> > Simon Fraser University
> > 8888 University Drive
> > Burnaby, BC, V5A1S6
> > Phone: 604-291-5625
> > Fax: 604-291-3496
> > Personal site: http://www.sfu.ca/~rvosa
> > FAB* lab: http://www.sfu.ca/~fabstar
> > Bio::Phylo: http://search.cpan.org/~rvosa/Bio-Phylo/
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++
> >
> >
> > _______________________________________________
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> > Bioperl-l at lists.open-bio.org
> > http://lists.open-bio.org/mailman/listinfo/bioperl-l
>
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-- 
______ _/      _/_____________________________________________________
      _/      _/
     _/  _/  _/  Heikki Lehvaslaiho    heikki at_sanbi _ac _za
    _/_/_/_/_/  Associate Professor    skype: heikki_lehvaslaiho
   _/  _/  _/  SANBI, South African National Bioinformatics Institute
  _/  _/  _/  University of the Western Cape, South Africa
     _/      Phone: +27 21 959 2096   FAX: +27 21 959 2512
___ _/_/_/_/_/________________________________________________________