Hi Andy! Andy Wingo <[EMAIL PROTECTED]> writes:
> * Generic application only works for instances of <generic>, or for > instances of a couple of other specially blessed classes. This is > because for these classes, the C code knows how the objects will be > laid out in memory, and can access memory directly instead of using > slot-ref. In general in GOOPS (and in MOPs in general) there is a > tension between extensibility and efficiency; the former is expressed > in protocols of generic functions, and the latter in invariants and > possibilities for direct memory access. > > The evaluator really needs to be able to do direct memory access, if > possible. So for that reason the existing bits of generic function > dispatch that are wired into eval.c check instances of those blessed > clases, via checks like (SCM_OBJ_CLASS_FLAGS (proc) & > SCM_CLASSF_PURE_GENERIC). > > This "direct memory access" also has repercussions in tail recursion; > that if the code to dispatch a method can't bottom out in eval.c, we > lose tail recursion. > > So, we need to add support for instances of subclasses of <generic>, > without losing efficiency. Apparently there is some code for this, see > goops.scm:apply-generic. (I realize this answers my previous message on `guile-user'...) Good to see you have idea on this! :-) > * We have no :before or :after methods. I don't know if STKlos had these > either. Not sure, but a nice thing to have. > * GOOPS should define a with-accessors macro. Actually, I don't like it a lot (probably because I wouldn't mind adding accessors to the global namespace). Do other CLOS-like systems have something similar? > * GOOPS reference should be folded into Guile's reference, as it is now > part of Guile. Not sure about it since it's quite a large document and it's easier to search it when it's separate. > * Possibly the worst section of Guile's manual: I like this one. :-) > * method cache code could be rewritten in C (dispatch.scm), although I > have never had a problem with it -- it doesn't show up on my profiles. I'd be reluctant to this, as it's already complex enough. Thanks for this instructing (and entertaining) review! Ludo'.
