Using Enums

Some examples (inspired by the Java Enum Tutorial):

Or with a bit of refactoring, you could write the switch like this:

Here is a coin example:

Here is a planet example:

Note: there are currently issues with using Groovy enums in conjunction with GroovyShell. Best bet would be to check Jira if you are having problems, e.g. http://jira.codehaus.org/browse/GROOVY-2135