|Perl Monk, Perl Meditation|
Re: On moving forward and breaking compatibilityby crashtest (Curate)
|on Feb 10, 2010 at 21:43 UTC||Need Help??|
I think you make some valid points, but I disagree with you on your interpretation of module version numbers. For me, even a "point" release could indicate a change in functionality that might break my script. Those are my expectations. Clearly, yours are quite different.
Considering that my point of view wasn't based on anything but a "feel" for how CPAN modules are released, I decided to consult the Perl documentation.
Take care when changing a released module. Always strive to remain compatible with previous released versions. Otherwise try to add a mechanism to revert to the old behavior if people rely on it. Document incompatible changes.
OK so far. Reading further, from perlmodstyle:
Modules which are "stable" should not break backwards compatibility without at least a long transition phase and a major change in version number.(emphasis mine)... but also:
Version numbers should indicate at least major and minor releases, and possibly sub-minor releases. A major release is one in which most of the functionality has changed, or in which major new functionality is added. A minor release is one in which a small amount of functionality has been added or changed. Sub-minor version numbers are usually used for changes which do not affect functionality, such as documentation patches.(Emphasis mine, again).
The way I read the documentation, I don't see any indication that WWW::Mechanize broke any rules of conduct here.
Most of your consternation seems to stem from the strong expectation that going from version 1.34 to 1.49_01 would preserve all functionality. I think that expectation is misguided. Perhaps other Monks disagree. Depending on the needs of a production environment, I would not upgrade modules to new "point" releases without moderate testing. God knows I've seen enough bug-fix releases (in non-CPAN software) that broke perfectly working functionality in other areas.
I like your ideas on preparing and communicating functionality changes. Perhaps your node could be a general-purpose tutorial for module maintenance.
Anyway, those are my $0.02.