definterface is generally considered a low-level tool in Clojure and typically Clojure developers do not create interfaces directly like this.
The two primary means of function abstraction/polymorphism are multimethods (can dispatch on any aspect of any of the parameters to a function) and protocols (which dispatch on the type of the first parameter to the function). There are tradeoffs between these - the former is very flexible, the latter is very similar to interfaces (and does use them under the hood) so is limited to type-based dispatch but gets all the JVM performance of that operation. On Saturday, July 17, 2021 at 7:44:18 PM UTC-5 jack...@topicquests.org wrote: > Tanya, > > That did help, swapping ie4clj.api.Inferrable for its import. > That, of course, got me into the next coding bug, about which I shall ask > next (I am attempting to use doseq to walk a list and AND its Inferrable > members) > > Meanwhile, I am truly surprised that you said > > I don't think it is the right way to use interfaces in clojure. >> > It's likely a result of dyslexia that I did not see that coming after > studying all the online banter about interfaces and protocols.. I chose > definterface because the examples showed how to specify the return values, > and programming by interface is how I do Java. I'd like to discover what, > precisely, to read and get past dyslexic events to learn how to use > interfaces. > > Many thanks > Jack > > On Sat, Jul 17, 2021 at 4:10 PM Tanya Moldovan <tanya.m...@gmail.com> > wrote: > >> Hi, >> >> I don't think it is the right way to use interfaces in clojure. Take a >> look at this >> <https://medium.com/@ujjawaldixit099/implementing-java-interfaces-in-clojure-3e5f0b80ba14> >> and this >> <https://stackoverflow.com/questions/8614734/how-do-i-implement-a-java-interface-in-clojure/8615002> >> . >> You could create a java project with the interfaces you need and import >> that instead. >> >> I think the issue is that this setup requires AOT and it might be missing >> from your configuration. >> To fix it try adding this to project.clj file: >> >> :profiles {:dev {:aot [ie4clj.api]}} >> >> It can be tricky If you want to do lein uberjar and generate a jar file. >> >> Alternatively, you can use compile-files >> <https://clojuredocs.org/clojure.core/*compile-files*> (then you don't >> need import statement). >> (note that in your gist you had some errors when defining AndList, I've >> fixed it) >> (also take a look at the clojure style guide >> <https://github.com/bbatsov/clojure-style-guide>, as AndList is not >> really the way to name things in clojure )) ) >> >> (ns ie4clj.api) >> >> (definterface Inferrable >> (^boolean eval []) >> (^boolean evalMembers [members])) >> >> (ns ie4clj.AndList) >> >> (when *compile-files* >> (require 'ie4clj.api)) >> >> (def AndList >> (reify >> ie4clj.api.Inferrable >> (eval [_] true) >> (evalMembers [_ m] true))) >> >> Hope this helps, >> >> >> >> On Sat, 17 Jul 2021 at 21:06, Jack Park <jack...@topicquests.org> wrote: >> >>> I created a gist >>> https://gist.github.com/KnowledgeGarden/39742ae9ae641f0d8facb31b288ece4c >>> >>> which explains a ClassNotFoundException when I am importing and reifying >>> a particular interface in another clj file. >>> >>> It's really baffling because, in the load order, core calls a test in a >>> test file - getting that to compile landed on the solution of an (:import >>> ...) statement; once that worked, then the code in that test calls another >>> file AndList.clj which happens to have several places where it reifies the >>> same interface. Except, with the same import statement, on that file, I get >>> the error. Difficult to even find a decent StackOverflow because one such >>> StackOverflow appears to be very similar, and the suggested fix is what I >>> have now. >>> >>> Thanks in advance for ideas. >>> Jack >>> >>> -- >>> 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 >>> 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 >>> 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. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/clojure/ffb09a94-5aa4-4600-8c9a-e0d00901df72n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/clojure/ffb09a94-5aa4-4600-8c9a-e0d00901df72n%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- >> 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 >> 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 >> 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. >> > To view this discussion on the web visit >> https://groups.google.com/d/msgid/clojure/CADBYUPvwWc0UqGZ-WdgtvAmkzH0RZ34_0EbbLs3QshFC2%2B3BGw%40mail.gmail.com >> >> <https://groups.google.com/d/msgid/clojure/CADBYUPvwWc0UqGZ-WdgtvAmkzH0RZ34_0EbbLs3QshFC2%2B3BGw%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "Clojure" group. 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