Ticket #95 (new feature request)

Description

Vlado Benko pointed out that it would be helpful if the word-sketch building function checked the grammaticality (in the Computer Science sense) of a sketch grammar file before trying to parse a corpus with it, maybe also making warnings if there was something that looked wrong even if it was not formally wrong. Is that possible? As we develop the potential for (eg) lexicom students to upload and run sketch grammars, so it will become more important.