Happy and Macros (was Re: ANNOUNCE: Happy 1.10 released)

Carl R. Witty [email protected]
11 May 2001 10:13:49 -0700


"Manuel M. T. Chakravarty" <[email protected]> writes:

> I don't think, the point is the test for non-ambiguity.  At
> least, Doitse's and my self-optimising parser combinator
> library will detect that a grammar is ambigious when you
> parse a sentence involving the ambiguous productions.  So,
> you can check that by parsing a file involving all grammar
> constructs of the language.

Sorry, doesn't work.  Where do you get this "file involving all
grammar constructs of the language"?

If such an approach worked, you could use it to determine whether an
arbitrary context-free grammar was ambiguous; but this problem is
undecidable.

Carl Witty