Hi Albert, I made sense of this by keeping the concept of defprotocol separate from definterface and deftype. defprotocol is like multimethods and deftype is like creating an implementation of an interface. You then need to instantiate a new instance of the deftype to execute its methods. The following repl session shows this;
./repl.sh Clojure 1.2.0-master-SNAPSHOT user=> (set! *warn-on-reflection* true) true user=> (defprotocol PTest (test-it [msg])) PTest user=> (extend-protocol PTest nil (test-it[msg] "Nix")) nil user=> (extend-protocol PTest String (test-it[msg] msg)) nil user=> (definterface ITest (test_it ^boolean [^String msg])) user.ITest user=> (deftype Test [] ITest (test-it [this msg] (> (.length msg) 0))) user.Test user=> (test-it nil) "Nix" user=> (test-it "two") "two" user=> (let [tt (Test.)] (.test-it tt "hello")) true Note where you do and don't need type hints (there are no reflection warnings). Also note that I used test_it in the definterface. There are probably ways of creating types on protocols, but I haven't tried that yet. -Hth, Adrian On Tue, Aug 31, 2010 at 11:20 PM, Albert Cardona <sapri...@gmail.com> wrote: > Hi all, > > I am puzzled by the type hint support in deftype. > I can add type hints to defprotocol: > > user=> (defprotocol PTest > (test-it ^boolean [this ^String msg])) > PTest > > … but adding them to deftype fails: > > > user=> (deftype Test [^String name] > PTest > (test-it [this msg] (str "test " name ": " msg \space (.length msg)))) > java.lang.IllegalArgumentException: Can't find matching method: > test_it, leave off hints for auto match. (NO_SOURCE_FILE:1) > > > So I write the deftype without type hints: > > user=> (deftype Test [^String name] > PTest > (test-it [this msg] (str "test " name ": " msg \space (.length msg)))) > user.Test > > > But then, I get reflection warnings: > > user=> (set! *warn-on-reflection* true) > true > > user=> (test-it (Test. "one") "two") > "test one: two 3" > > 8/31/10 11:11:49 PM [0x0-0x29029].org.fiji[382] Reflection warning, > NO_SOURCE_PATH:3 - reference to field length can't be resolved. > > In any case "length" is a method, not a field, in String. > > The above is just a minimal example. I am experiencing this issue in > just about all deftype that I need to type-hint. > > The error when type-hinting suggests that the latter is unnecessary, > that it could be deduced from the hints in the protocol > definition--but that is not the case. > > What am I missing? Thanks for any help. > > Albert > > -- > http://albert.rierol.net > -- 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
