Yeah, that's another good example where a protocol might be helpful. Arguably, you could make a case for nearly all of Clojure's abstractions being backed by a protocol. It has certainly proved to be a very useful technique in core.matrix
I don't think there's even much performance downside of doing so: the dispatch code can just check if an object is of the right interface e.g. (instance? IMeta foo) and only if that fails then fall back to a protocol-style dispatch lookup. On Saturday, 31 August 2013 13:53:20 UTC+8, Colin Fleming wrote: > > I've also been interested in this for Named (a protocol for things I can > call "name" on), although my use-case is mostly interop with Java > frameworks. > > > On 31 August 2013 15:13, Mikera <mike.r.an...@gmail.com <javascript:>>wrote: > >> It would be better, I think, if metadata was attachable via a protocol >> rather than than a wrapper: then you could just extend the protocol to any >> arbitrary Java class. Wrappers are a pain to make work because of wrapping >> / unwrapping and protocols also have the advantage of being very efficient. >> >> I've wanted a similar feature with respect to "seq" as well (a protocol >> for things that can be treated as sequences) >> >> On Saturday, 31 August 2013 03:16:26 UTC+8, JvJ wrote: >>> >>> I've noticed that, when doing a lot of Java interop, it's impossible to >>> attach metadata to most Java objects, since they don't implement the IMeta >>> interface. A workaround for this would be to do something like put every >>> Java object in a single-element list and attach metadata to the list, but >>> this is annoying. Would it be possible (or even useful) to create some >>> kind of generic IMeta structure that can wrap other Java objects and have >>> them act like normal, except for the added metadata (or even other >>> Clojure-esque features)? >>> >> -- >> -- >> You received this message because you are subscribed to the Google >> Groups "Clojure" group. >> To post to this group, send email to clo...@googlegroups.com<javascript:> >> Note that posts from new members are moderated - please be patient with >> your first post. >> To unsubscribe from this group, send email to >> clojure+u...@googlegroups.com <javascript:> >> For more options, visit this group at >> http://groups.google.com/group/clojure?hl=en >> --- >> You received this message because you are subscribed to the Google Groups >> "Clojure" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to clojure+u...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > -- -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
