[antlr-interest] grammarDecisionDescription

[Benjamin S Wolf]

I'm trying to debug my grammar, and the book suggests retrieving a
variable from the error object called "grammarDecisionDescription".
However, all NoViableAltExceptions antlr generates are of the form

nvae = NoViableAltException("", 5, 0, self.input)

with the "" being the argument set as grammarDecisionDescription. The
templates indicate that the "" should be "<description>" (which is
also placed in a comment several lines above), but it is always empty
in this section of the generated code. Is there a way to enable this?