Codeco: A grammar notation for controlled natural language in predictive editors

Existing grammar frameworks do not work out particularly well for controlled natural languages (CNL), especially if they are to be used in predictive editors. I introduce in this paper a new grammar notation, called Codeco, which is designed specifically for CNLs and predictive editors. Two different parsers have been implemented and a large subset of Attemp to Controlled English (ACE) has been represented in Codeco. The results show that Codeco is practical, adequate and efficient.