If you don't want to wrap the object in an atom, you can also reify an object that supports IDeref which returns your object. All reified objects support IObj out of the box.
On Sunday, August 31, 2014 4:55:58 AM UTC-4, Atamert Ölçgen wrote: > > Hi Francis, > > > On Sat, Aug 30, 2014 at 1:34 PM, Francis Avila <fran...@gmail.com > <javascript:>> wrote: > >> It would probably help if you said more about the source of this >> atom-holding object. Is it a plain Java class? A deftype/defrecord? Is it >> final? >> > > It's not an atom-holding object. The only guarantee is that this object > extends one (or two) of these protocols: > http://clecs.muhuk.com/api/0.2.1/clecs.world.html > > Other than that, it can be anything. A Java class, or a type or a record... > > > >> >> >> If you can control the construction of this object and its class is not >> final, you can subclass it and add an IObj implementation. (Note that most, >> maybe all clojure ways of creating classes create final classes, so this >> technique won't work.) The easiest way to subclass is with `proxy`: >> >> (defn meta-AtomHolder [atom-value metadata] >> (proxy [AtomHolderClass clojure.lang.IObj] ;; [superclass, new >> interfaces] >> [atom-value] ;; constructor args >> (meta [] metadata) ;; subclass method >> (withMeta [newmeta] (meta-AtomHolder newmeta)))) >> => (var user/meta-AtomHolder) >> (meta-AtomHolder (atom "x") {}) >> => #<AtomHolderClass$IObj$40298964 >> user.proxy$AtomHolderClass$IObj$40298964@302c28cc> >> (meta (meta-AtomHolder (atom "x") {})) >> => {} >> (meta (with-meta (meta-AtomHolder (atom "x") {}) {:a 1})) >> => {:a 1} >> > > This is really cool. So I can do (deref (meta-AtomHolder (atom "x") {})) > and it would return "x", right? > > I have actually managed to solve it using vars, had to move things around > a bit: > https://github.com/muhuk/clecs/blob/master/src/clecs/world/check.clj#L73 > > > >> >> If the parent class is final or you can't construct the object yourself, >> you need to delegate method calls from one instance to this object >> instance. I think this is hard-but-not-impossible in java, but I'm not sure. >> >> (Clojurescript has `specify`, which does exactly what you want, but only >> exists because delegation between instances in javascript is trivial.) >> >> On Friday, August 29, 2014 10:16:05 PM UTC-5, Atamert Ölçgen wrote: >>> >>> Obviously I can't. >>> >>> But I need to add this capability to an object. During testing I attach >>> meta to this object that contains an atom. Then I pass this object to other >>> functions, known in runtime. I can't use a dynamic var because all this >>> happens within a mock function that may be retried and run in different >>> threads. >>> >>> I have seen this: http://stackoverflow.com/questions/20724219/ >>> simplest-possible-clojure-object-that-can-accept-a- >>> primitive-and-metadata but can't deref it since I can't change the >>> functions that will use it later. If I wrap this object I need to be able >>> to delegate all of its functionality to the original object. >>> >>> I hope this all is not too vague. The code I'm working on is not online >>> yet. But it's for clecs (https://github.com/muhuk/clecs/), I'm adding >>> quickcheck to compare different world implementations. >>> >>> >>> -- >>> Kind Regards, >>> Atamert Ölçgen >>> >>> -+- >>> --+ >>> +++ >>> >>> www.muhuk.com >>> >> -- >> 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/d/optout. >> > > > > -- > Kind Regards, > Atamert Ölçgen > > -+- > --+ > +++ > > www.muhuk.com > -- 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.
