Extensible Grammars?

[Matthew Johnson]

Back when I was using the EOPL 2 code base in DrScheme, I was able to
extend a given grammar simply by appending new productions to the list
"the-grammar". SLLGEN didn't seem to mind. I also extended the
interpreter incrementally in an analogous way.

Since EOPL 3, however, SLLGEN is checking the syntax-object and
anything other than a simple quoted list literal throws a "bad grammar
specification" error.

I very much prefer being able to incrementally extend both the grammar
and the interpreter procedures, rather than simply reproduce them in
their entirety with the new stuff added. I am not sure I fully
understand how the Scheme/Racket syntax-objects work... Is there an
easy way to make the test in SLLGEN a bit more forgiving?

Thanks for your time,
Matthew