Why not trying it right away in the REPL? user=> (defrecord Bar [state]) ; <- not implementing IFn > user.Bar > user=> ((->Bar "foo"))
> ClassCastException user.Bar cannot be cast to clojure.lang.IFn > user/eval15532 (form-init5689008917050406381.clj:1) > user=> (defrecord Foo [state] clojure.lang.IFn (invoke [this] (println "my > state is" state))) > user.Foo > user=> ((->Foo "foo")) > my state is foo > nil user=> ((->Foo "foo" "bar")) > ArityException Wrong number of args (2) passed to: > user/eval15486/->Foo--15498 clojure.lang.AFn.throwArity (AFn.java:429) Here you have it: implementing IFn is enough to use a record as a function. You can then implement just the arities you're interested into. Cheers, c. Il giorno giovedì 14 maggio 2015 21:32:37 UTC+2, piast...@gmail.com ha scritto: > > The docs offer this example: > > https://clojuredocs.org/clojure.core/defrecord > > user=> (defrecord Someone [nick-name preffered-drink] Fun-Time (drinky-drinky > [_] (str nick-name "(having " preffered-drink "): uuumm"))) > user.Someone > > user=> (def dude (->Someone "belun" "daiquiri")) > #'user/dude > > user=> (drinky-drinky dude) > "belun(having daiquiri): uuumm" > > But if a record implements clojure.lang.IFn it can be called directly? Do I > understand this correctly? When I run macroexpand-all on defrecord-ifn, as > defined here: > > https://github.com/overtone/overtone/blob/e200075da27375727db1f5ce342e2e1c22ea1dbd/src/overtone/helpers/lib.clj > > I see that it extends clojure.lang.IFn as in: > > clojure.lang.IFn > (invoke [this__1446__auto__] > ((fn [this & args] > (apply synth-player sdef params this [:tail instance-group] args)) > this__1446__auto__)) > (invoke [this__1447__auto__ arg0] > ((fn [this & args] > (apply synth-player sdef params this [:tail instance-group] args)) > this__1447__auto__ arg0)) > // etc, all 20 arities are defined > > So, that means I could call the record as a function? > > > -- 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/d/optout.
