On Jan 27, 2007, at 11:11 AM, Mark Wassell wrote:

Sometimes happy outputs 'parE' when I run it on my .y file? I believe it is coming from a part of Grammer.lhs which has the comment line

"This bit is a real mess, mainly because of the error message support."

Are there any suggestions on what to change in my .y file to get over this?

I've run into this problem as well (and submitted a bug report). You get the problem when there are undefined productions in your grammar. For instance: %name parser Foo %% Foo : Bar { () } / Ulf