Re: Reductions during Bison error handling

[Akim Demaille]

| HA > So I think the efficient error recovery must include semantic 
information;
| 
| Yes, Corbett and others reached similar conclusions.  They would cite
| examples like
| 
|        A(3) : f;
| 
| where in Ada, an appropriate replacement is A(3) := f; if A is an
| array and f is a variable, and A(3) ; f; if A and f are procedures.

Given where you are, maybe you would have access to some
implementation of Corbett's Pascal Auditor?  Although we didn't
struggle very hard, we did try to use his error recovery scheme in
Bison, but it was a failure.  I could not find any hint of how the
stack should be massaged etc.  Having an original .y file would help
understanding how it was to be used.

This is why bison.hairy has, finally, been removed.  It will be,
anyway, at least as easy to re-implement support from scratch, as to
try to use the (probably broken) remains that were left in Bison until
recently.