[antlr-interest] Do I have to use lex state in this case?

[Martin Probst]

Hi,

I don't think you'll get around a stateful lexer. Those are ugly (I
know!) but they work. But yours should be quite simple:

a := /foo/ --> RegExp
a := foo / bar --> div

You have two states: expecting an operand and expecting and operator. If
your expecting and operator, '/' is the start of a regular expression.
Otherwise (operand) it's a div. Shouldn't be too difficult - it's just
very annoying to put all the state transitions into place.

> For extra credit :-), do you want to match C++ style comments, too? 
> from "//" to the end of the line?

Well, just lex & parse it as an empty regular expression and then
optimizie it away ;-)

Martin