Support for grun

[phdoerfler]

I'd like to test the generated parser using grun aka org.antlr.v4.gui.TestRig. Amongst other things it provides a simple GUI:

This is probably trivial to do if the example on the ANTLR website is anything to go by:

$ antlr4 Expr.g4
$ javac Expr*.java
$ grun Expr prog -gui
100+2*34
^D

How about adding a task "grun" or perhaps run in Antlr4 or test in Antlr4 that starts grun? Thoughts?

[ihji]

Yes, definitely good to have. I will add this feature sooner or later but can't promise the exact date (PRs are always welcome btw 😄 )