A few months ago, I started re-examining some of the legacy JavaCC syntax. I realized the pure absurdity of having to write: LOOKAHEAD(Foo() Bar() Baz()) Foo() Bar() Baz() In short order, I allowed people to write the above as: LOOKAHEAD Foo() Bar() Baz() But this started me thinking…. I reasoned that there were doubtless plenty …
In my last post I reported that I had finally fixed the way syntactic lookahead works in JavaCC. This leads to the natural question: what about semantic lookahead? Well, what is historically called semantic lookahead in JavaCC is actually misnamed. It’s really just a bit of java code that is used to determine whether to enter an expansion or not. Something like: …
Fixed a Longstanding Bug Known Issue in JavaCC: Nested syntactic lookahead now works! There is a quite serious bug (let’s just call it by what it is, shall we?) of very long standing in JavaCC. Basically, syntactic lookaheads do not nest. This bug is documented in Theodore Norvell’s JavaCC FAQ, which by the way, is the best …
Bugfix! Nested syntactic lookahead now works correctly! Read More »