Scala’s command-line interpreter (its REPL) is highly useful, but if you’re accustomed to readline, you’ll find it lacking and frustrating. Scala 2.8 is enhancing the REPL, but in the meantime, here’s a handy trick.

Instead of typing

$ scala

try this, instead:

$ rlwrap scala -Xnojline

By disabling JLine and invoking Scala via rlwrap, you get full readline capabilities in the Scala REPL.

On Windows, you can install the Cygwin version of rlwrap; it seems to work just fine in my tests.

Thanks to Tony Morris for posting this tip to the scala-user mailing list.