6.5 Compiling to byte-code

All Scheme functions and source files are invisibly compiled into internal Java byte-codes. (A traditional interpreter is used for macro-expansion. Kawa used to also interpret “simple” expressions in interactive mode, but always compiling makes things more consistent, and allows for better stack traces on errors.)

To save speed when loading large Scheme source files, you probably want to pre-compile them and save them on your local disk. There are two ways to do this.

You can compile a Scheme source file to a single archive file. You do this using the compile-file function. The result is a single file that you can move around and load just like the .scm source file. You just specify the name of the archive file to the load procedure. Currently, the archive is a "zip" archive and has extension ".zip"; a future release will probably use "Java Archive" (jar) files. The advantage of compiling to an archive is that it is simple and transparent.

Alternatively, you can compile a Scheme source file to a collection of ‘.class’ files. You then use the standard Java class loading mechanism to load the code. The compiled class files do have to be installed somewhere in the CLASSPATH.