Extending IFn
I'm experimenting with creating my own fn types. I was wondering if there was a better way of extending IFn than this: https://gist.github.com/1321330 Is there a more idiomatic way? -- 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
Re: Extending IFn
Hi, since IFn is a Java interface and not a protocol, I'm afraid there is no better way to define this. However I would write the macro slightly differently. I find this more approachable. YMMV. (def max-arities 20) (defmacro definvokable [type fields & deftype-tail] (let [f(fields 0) args (repeatedly max-arities gensym) arity(fn [n] (let [args (take n args)] `(invoke [this# ~@args] ((. this# ~f) ~@args vararg `(invoke [this# ~@args more#] (apply (. this# ~f) ~@args more#)) apply-to `(applyTo [this# args#] (apply (. this# ~f) args#))] `(deftype ~type ~fields clojure.lang.IFn ~@(map arity (range (inc max-arities))) ~vararg ~apply-to ~@deftype-tail))) Sincerely Meikel -- 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
Re: Extending IFn
Eh, I was afraid the interface would be a problem. So there isn't a good way to reuse interface implementations for interacting w/ legacy Java quite yet. I do like your approach to the macro better. As usual you deliver, Meikel :) Sean On Oct 28, 3:11 am, "Meikel Brandmeyer (kotarak)" wrote: > Hi, > > since IFn is a Java interface and not a protocol, I'm afraid there is no > better way to define this. However I would write the macro slightly > differently. I find this more approachable. YMMV. > > (def max-arities 20) > > (defmacro definvokable > [type fields & deftype-tail] > (let [f (fields 0) > args (repeatedly max-arities gensym) > arity (fn [n] > (let [args (take n args)] > `(invoke [this# ~@args] ((. this# ~f) ~@args > vararg `(invoke [this# ~@args more#] > (apply (. this# ~f) ~@args more#)) > apply-to `(applyTo [this# args#] (apply (. this# ~f) args#))] > `(deftype ~type > ~fields > clojure.lang.IFn > ~@(map arity (range (inc max-arities))) > ~vararg > ~apply-to > ~@deftype-tail))) > > Sincerely > Meikel -- 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
