On 17 Set, 17:34, Doug Philips <douglas.phil...@gmail.com> wrote: > On Fri, Sep 17, 2010 at 08:50, Alessio Stalla <alessiosta...@gmail.com> wrote: > > On Sep 16, 4:10 pm, Nicolas Oury <nicolas.o...@gmail.com> wrote: > > Note also that the OP's original example does not require anything > > more than what defmacro already provides. And turning function calls > > into macro calls is not a great idea; it won't cover the use of apply > > and similar. > > Hmmm, that's odd. Perhaps I've missed a message somehow, but I'm not > sure why name-space manipulation isn't the right thing to use. > To condense, I want to "change the behaviour" of (foo ...), is that right? > If so, then instead of getting the definition of foo from its usual > name space, couldn't I get it from a 'tracing foo' name space or > 'wrapping foo in bar' name space? I think I could do this with > macros, such that the usual name space that foo comes from is used, > but foo is 'redefined' with a macro to do something that masquerades > as foo and probably/maybe calls the 'real' foo eventually. Problem is > that macros interact with apply, etc. so I'm back to thinking name > space manipulations are the right thing, or that I've skimmed too much > and don't understand the problem. :-)
Hmm. I can't quite understand what you mean by namespace manipulations, because my Clojure-fu is really limited, I'm just lurking here to keep in touch with what happens in "the other camp" ;) Anyway, I don't think it's *you* the one who "gets the definition of foo from the <whatever> namespace"; it's the Clojure system that does. So if you want to make Clojure see a different foo, you have to redefine - or rebind, with the appropriate caveats - foo. Redefining it as a function is sufficient; introducing a macro doesn't buy anything in this case: it forces you to recompile all the code that uses foo, even third-party code, and makes the new foo lose its first- class object status. In general, using a macro to modify the behaviour of existing code is dangerous and smells a little too much like C ;) Just my €.02, Alessio -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
