Kawa (Scheme implementation)

Kawa

Family	Lisp
Designed by	Per Bothner
Developer	The Kawa Community
First appeared	9 February 1998 (1998-02-09)
Stable release	3.1.1 / 16 January 2020 (2020-01-16) (w/R7RS compatibility)
Implementation language	Java, Scheme
Platform	Java virtual machine
OS	Cross-platform
License	MIT
Website	www.gnu.org/software/kawa
Influenced by
Lisp, Scheme

Kawa is a language framework written in the programming language Java that implements the programming language Scheme, a dialect of Lisp, and can be used to implement other languages to run on the Java virtual machine (JVM). It is a part of the GNU Project.

The name Kawa comes from the Polish word for coffee; a play on words, since Java is another familiar name for coffee.

Integration with Java

Besides using the language Scheme, Java object fields and methods can be accessed using code such as: (invoke object 'method argument ...). This will invoke a Java method, and does the same thing as object.method(argument, ...) in Java. An object's fields can be accessed with: object:field-name or (invoke object 'field-name). Static (class) methods can be invoked with the function invoke-static. Kawa can be extended with Java code (by creating scheme functions in Java), and combined with other JVM implementations.

How to use

Kawa can be run normally via the kawa script:

$ kawa [optional arguments] ...

Alternatively, Kawa can be run by hand:

$ java -jar /path/to/kawa/kawa.jar [optional arguments] ...

To compile a Scheme file to a class file, the -C parameter is used:

$ java kawa.repl --main -C file.scm

This will produce file.class, which can be run by typing java file. It is also possible to create an applet or servlet (to compile a servlet, servlet-xxx.jar must be in the CLASSPATH variable).

See also

• List of JVM languages
• List of open-source programming languages

External links

• Official website