Why does clojure convert dashes in names to underscores in the filesystem?

Question

I have been using clojure for a couple of months now and one thing I really don\'t understand is why dashes in namespace names must be represented as underscores in the file

Answer 1

It's a necessary workaround for Java interoperability.

When a Clojure namespace is AOT (ahead-of-time) compiled into a Java .class file, it has to have a name that is a valid Java identifier. Dashes aren't valid in Java class names, so Clojure converts them to underscores. It also converts characters like * into words like _STAR_.

Answer 2

Do you mean that the .class files on disk have underscores where the functions in Clojure had dashes? I'm sure I read that it's something to do with the JVM not supporting dashes in those file names. (Or at least it not being a guarantee that it supports them.)

This is only a limitation of the class file names, and Clojure silently deals with this problem anyway. Your own code can still handle files with dashes in the filename.

I'm sorry that I don't have a reference for this right now.