Why to incorporate a data definition language into a CAD frameworks extension language

Discusses extension languages for CAD frameworks. The authors show that the incorporation of a data definition language (DDL) not only makes sense but is a must for a serious extension language, if it intends to meet all requirements that occur in CAD frameworks. To illustrate this approach the authors introduce TIDL (tool integration description language), a representative for an extension language with an incorporated DDL.<<ETX>>