2015-07-07 15:04 GMT+02:00 Jo Geraerts <j...@umask.net>: > > * multiply(long x) > * multiply(double x) > * multiply(Number x) > > In clojure i want to do something like > > (defn multiply[^MonetaryAmount amount multiplicant] > (.multiply amount multiplicant)) >
Function parameters in Clojure, are generally passed as a java.lang.Object, so numbers are boxed by default. Clojure does have infrastructure to pass primitive numbers, see invokePrim here: https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/IFn.java#L97 see also http://clojure.org/java_interop#Java Interop-Support for Java Primitives however, this requires a specific type hint on the multiply fn, so normally that means separate multiply-double and multiply-long fns. The way I would do it: Define multiply as a function calling (.multiply amount ^Number x), for higher order usage, and then add an :inline function to its metadata, which returns `(.multiply ~amount ~x). That acts as a compiler macro, which inlines the call to .multiply, that way, its parameter type can be assigned via local type inferrence (which clojure does). See http://www.bytopia.org/2014/07/07/inline-functions-in-clojure/#sec-3 Beware, that inline functions aren't public API and subject to change. kind regards -- 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.
