unexpected "Program error:"

[Dean Herington]

Keith,

Your intuition was exactly right.  I was missing a branch in "thenP".  It
works fine now.  Thanks!

Dean

P.S. Couldn't the message be a bit more helpful?


On Mon, 16 Oct 2000, Keith Wansbrough wrote:

> > I'm getting an unexpected "Program error:" in a situation where I don't
> > think "error" is being called.  Moreover, the error message is bizarre,
> > though I can see in the gobbledy-gook the structure of the piece of my
> > program where things are going awry.  The exact message (except for
> > addition of some line breaks) is:
> > 
> > Program error: {thenP_v1700 parser_v1798 ((initialSymbols [] (Num_fromInt
> >  instNum_v33 0),Num_fromInt instNum_v33 0),ParseResult_Failed
> >  (Posn_Pn_v1551 (Num_fromInt instNum_v33 0) (Num_fromInt instNum_v33 0)
> >  (Num_fromInt instNum_v33 0)) "Parse error")}
> 
> IIRC, "Program error:" means that a branch was missing from a case
> expression.  It looks like it's in your parsing library, perhaps in
> its definition of thenP.  If you posted the whole program (if it's not
> too big) we might be able to help further.
> 
> --KW 8-)