Re: Two problems with the GLR parsers

[Akim Demaille]

| As the starred lines indicate, the error token is shifted 4 times!
| Fortunately, the reduction is taken only once.  I'm not sure what to
| make of this, so I'll ask around before I try to make glr duplicate
| the behavior (or, of course, change input.at).

Nice audit analysis!  Thanks Paul!  Actually, this is also the
demonstration that this test is too weak: the location should really
be a range to be meaningfull: error's location should certainly start
at the discarded token, and end when the reduction is taken.

I'll try to extend the test ASAP.  I'll also try to fix the error
handling in Yacc.  But I'm running low on time: I leave at the end of
next week for a month :(