Why does RegexTest have a main method?

Question

I wonder why scala.util.parsing.combinator.testing.RegexTest has a main method.

Aren't library classes intended to be called from within the program and not run separately as an independent executable?

Answer 1

That's not the only one. One I particularly like is scala.swing.test.UIDemo. I really, really don't think they ought to be bundled with the library, but they are. Basically, they are examples you can run directly:

scala scala.swing.test.UIDemo