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Postings from June 2002
>>>>> "JS" == John Siracusa <siracusa@mindspring.com> writes: JS> But what if they use Local:: and then want to use someone else's JS> Local:: modules? (Say they purchased another company or are JS> partnering with someone.) What if they want to release their code JS> to CPAN, despite the fact that it may still be vendor-specific? JS> (e.g. a parser for Acme's electronic widget order receipt or JS> something.) I think there are real problems to be solved here. one idea i have seen but could be formalized is a way to load a module which is named Foo::Bar and have it not affect the actual current symbol tables. instead another namespace is installed which maps to the loaded file's space. that module could be loaded as Local::Foo::Bar. all mentions of Foo::Bar in that module are changed (compile or runtime?) to the newly mapped namespace. so you can do module space renaming/aliasing at load time. this doesn't solve the issue with stopping or managing collisions but it allows any application to work around them. this load and rename needs a way to force a load path since the colliding modules would need to be installed under different load paths. this means the whole module load mechanism (which directly affects 6pan, its 6pan++ download tool module (CPAN.pm), and namespace management) will need a high level design to handle all these and other issues. larry wants to be able to load a selected version of installed modules. this involves a specialized file search and load operation which could share much design and code with searching for one of colliding pair of modules. similarly installing from 6pan (using 6pan.pm) should allow installation of multiple versions and also colliding modules. it may have to create special subdirs that perl6 would know to search for the variant or collided modules. so the design of 6pan, the mechanism for installing modules from there and how modules get loaded in perl are all a tangled hierarchy. nothing should be fixed in one of them before a quality high level design is done for the whole module subsystem. uri -- Uri Guttman ------ uri@stemsystems.com -------- http://www.stemsystems.com - Damian Conway Perl Classes -- July 1-3 -- http://stemsystems.com/class/ --- ----- Stem and Perl Development, Systems Architecture, Design and Coding ---- Search or Offer Perl Jobs ---------------------------- http://jobs.perl.orgThread Previous | Thread Next