On Monday, October 27, 2014 2:33:34 PM UTC-7, Volker Braun wrote: > > The you can just as well get rid of @cached_method, that of course also > solves the problem. >
Note quite, thanks to http://trac.sagemath.org/ticket/16316 , which basically implements the scheme Robert proposes and uses that automatically if a normal "hash" is not available. In general I expect that cached_methods should preprocess their arguments a bit before doing a key lookup anyway (such as do the required coercions on arguments). Most of the time, functions with arguments should *not* be cached, because their cache quickly becomes a memory leak. The most important place where caching happens is UniqueFactory/UniqueRepresentation. These are mostly parent constructors, so tend to be very lenient in their input specifications. So their input should probably be uniformized quite agressively before using as a key. The current interface doesn't make that particularly easy. > IMHO every immutable element ought to be hashable. > I agree with that. With the understanding that "a==b" => "hash(a) == hash(b)" is only guaranteed to apply when "parent(a) is parent(b)", hopefully extending a little beyond. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
