> > Okay. Functions as values. Go look at the IFn interface, > > https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/IFn.java. > >
Thanks for the link - this helps! When the clojure compiler generates a class type that conforms to this interface, does it generate a .java file which is then compiled using the java compiler? I am guessing not. I am guessing that clojure knows how to generate a byte code version of a class type directly. > In C or C++ you can take a raw machine pointer to a function. The JVM > does not allow for this behavior the result of which is that whenever > you have a "function" really what you have is a function-like object > with the standard application/invocation member methods. Thanks for explaining. This sounds very much like a C++ functor. For the record, the raw-pointer-to-function is the old-school thing to do in C++. These days functors are often used - object types that have the function application operator defined (which is a method with special function application syntax) - because these are more powerful (eg templated methods allowing compile-time polymorphism) and allow for better performance (eg inlining of code). So it sounds like what clojure does under-the-hood is to more-or-less define a functor type at compile time and then do various instantiations at run time. > The "standard" Clojure compiler is pretty braindead when it comes to the > emitted bytecode, but this is due to the philosophy (backed up by > experience) that the JIT is typically good enough. Good to know - thanks! This makes things clearer for me. > You could generate > better code, and my GSoC project is research into doing so but the > reality of Clojure programs is that function calls even with Var > indirection are free in comparison to the performance hits we take due > to using immutable datastructures and eschewing in place updates. > > Reid > -- 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.
