Hi David and all the others that replied, thank you for the answers, I think they help me a lot to get some perspective on how to use PDL::NiceSlice.
Best regards, Z. On Sat, May 28, 2011 at 5:59 PM, David Mertens <[email protected]> wrote: > Zeno - > > Others have addressed many of your questions. However, there is one > bit that I felt could get a little more attention: > > On Thu, May 26, 2011 at 5:21 AM, Zeno Gantner <[email protected]> wrote: >> <snip> >> >> By the way, PDL::NiceSlice is implemented as a Perl source filter, >> what can be a bit dangerous. >> What are the general recommendations towards PDL::NiceSlice? Is its >> usage encouraged? > > The basic problem is that a source filter simply reads in text and > applies overly simple text processing methods to do magic. This means > that most source filters are fragile, and when they break the errors > can be very weird. Source filters also do not (did not?) work with > modperl. This has been addressed on stack overflow here: > http://stackoverflow.com/questions/1785852/why-are-perl-source-filters-bad-and-when-is-it-ok-to-use-them > > However, source filters do allow arbitrary syntax modifications. They > may be brittle, but they would be impossible otherwise. Furthermore, > common operations should require very few keystrokes. Since slicing is > a very common operation, it makes sense to minimize the number of > keystrokes needed to perform such slicing operations, and that's why > NiceSlice was created. > > Source filters are difficult to test, but NiceSlice is used by many > PDL programmers and in that sense is thoroughly tested. You came > across the only major wart of using NiceSlice (in my opinion), which > is that errors may sometimes make no sense when you use NiceSlice. > However, you quickly learn to look at the line where the error > occurred, and when things mess up you try wrapping it in "no > PDL::NiceSlice" and "use PDL::NiceSlice" lines. > > Generally, source filters should be used sparingly. NiceSlice is one > of the few cases where their use makes sense. > > David > > -- > Sent via my carrier pigeon. > -- MyMediaLite Recommender System Library: http://ismll.de/mymedialite _______________________________________________ Perldl mailing list [email protected] http://mailman.jach.hawaii.edu/mailman/listinfo/perldl
