Is the following correct? The only way to define *multiple* mutable instance variables/fields for a class visible in Java is by using deftype with :volatile-mutable or :unsynchronized-mutable. The only way to inherit from a concrete Java class is by using gen-class or proxy. gen-class allows a single mutable field using :state and :init. Thus there is no way to define a class that both inherits from a concrete class and defines more than one new instance variable.
I believe these statements are correct, but gen-class is complex and deftype use has some nuances, so I want to make sure I haven't missed something. I know that I can use gen-class's state variable to hold multiple mutable structures by putting e.g. atoms inside of a map or record stored in the state variable, or by storing a deftype instance with mutable fields in the state variable. (Context: I'm getting a meaningful performance boost by replacing atoms in a map or a record in a gen-class state variable, with deftype with :volatile-mutable in a gen-class state variable. I keep wondering whether my gen-class class really needs to delegate to a deftype structure. This is for an application that needs to extend one or more Java classes. I know that :volatile-mutable and :unsynchronized-mutable are intended to be used only by experts. I'm not an expert. I've asked a question on StackOverflow <http://stackoverflow.com/questions/30472496/risks-of-volatile-mutable-fields-in-single-threaded-contexts> about whether the particular way that I'm using :volatile-mutable, i.e. solely in single-threaded application, is safe. Feel free to comment there or here on that issue, as well as on my main question above.) Thanks. -- 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.
