[joostdevries]

I use the sbt command ~testQuick. That continuously recompiles scala files as soon as they're saved and reruns only the unittest(s) that are affected by the change.

For running my app I use the revolver plugin that offers the same thing: as soon as I save a file it is compiled and the app is restarted. When I use the Play framework this is supported out of the box: I save my file and refresh in the browser and see the changes.

This works very well.

[saryant]

scalac is definitely slower than javac, but I do wonder if half the complaints about speed are from people who don't realize you can leave SBT running but rather do an "sbt compile" every time and end up waiting for JVM initialization.