james anderson wrote: > On 2009-07-21, at 01:18 , Robert Goldman wrote: > >> james anderson wrote: >>> On 2009-07-21, at 00:35 , Robert Goldman wrote: > [...] >>>> What would it mean, for >>>> example, to be :contingent-on or :weakly-depend on a :file? >>> if the file is present, then the contingent component is included in >>> the system and dependent on that file. >>> no different than a simple dependency. the only difference are in the >>> effective behaviour of operate. >>> in my case it makes it possible to do things like include a ffi >>> interface iff dependent on runtime conditionalization and include a >>> particular aspect of the higher level interface iff the particular >>> ffi interface is there. >> I don't believe that is correct. > > ? > in that weakly-depends-on does not do this, or this is not a > "correct" thing to do?
The former. weakly-depends-on does not do these sophisticated things. > i do not use weakly-depends-on. i implemented :contingent-on. > >> If you look at the source, >> weakly-depends-on is not handled as a first class citizen, the way >> :depends-on is. :depends-on is squirreled away in a slot, and then >> manipulated at the time we carry out an ASDF operation. The WEAKLY >> part >> of :weakly-depends-on, on the other hand (1) only works when the >> dependency is on a system, not a feature or a file and (2) is resolved >> when the defsystem is "parsed". I.e., there's no way you can load a >> system that has weakly-depends on, THEN define another system on which >> it weakly depends, and have the first system do anything reasonable. >> The :weakly-depends-on is gone by the time the second system is >> introduced to your lisp image. > > weakly depends on may well not be well implemented. i do not use it. Yes, that's my point. I'd rather it not become widely used, lest it become another oddity with which we must maintain backward compatibility. _______________________________________________ asdf-devel mailing list asdf-devel@common-lisp.net http://common-lisp.net/cgi-bin/mailman/listinfo/asdf-devel
