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Bud is yet another Scheme-like Lisp dialect implemented in Java.
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Bud is yet another Scheme-like Lisp dialect implemented in Java. It is simple, lightweight and embeddable. Most of the special forms including quote, lambda, if, cond, and, or and built-in functions like car, cdr, eq?, type predicates and arithmetic functions specified in R5RS are implemented.


  1. JDK 7+
  2. Apache Maven 3.0.4+


Like Scheme,

  1. Functions are first-class object.
  2. Functions and other data variables share a single namespace.
  3. Tail calls are properly optimized.

A list of data types that are currently supported are shown below.

  1. boolean
  2. character
  3. number (decimal)
  4. string
  5. symbol
  6. list
  7. function

How to use

Running REPL

Use the Maven wrapper to compile and execute,

./mvnw clean compile exec:java -Dexec.mainClass='me.predatorray.bud.lisp.BudRepl'

If the docker cli is available on your computer, you can just run the lastest zetaplusae/bud image published on Docker Hub,

docker run -it --rm zetaplusae/bud:latest

Or, you can try the REPL online.

Finally, type your Lisp expressions.

bud> "Hello, Bud!"
"Hello, Bud!"

Embed in your program

Install the artifact to your local repository.

mvn clean install

Add the dependency in you pom.xml.


And, here is an example of interpreting source code:

String sourceCode = "(+ 1 1)"
BudInterpreter interpreter = new BudInterpreter();
BudObject result = interpreter.execute(sourceCode);
assert new BudNumber(new BigDecimal(2)).equals(result);
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