SWI-Prolog version 7 extensions

ABSTRACT. SWI-Prolog version~7 extends the Prolog language further as a general purpose programming language that can be used as `glue' between components written in different languages. Taking this role rather than that of a DSL \emph{inside} other IT components has always been the design objective of SWI-Prolog as illustrated by XPCE (its object oriented communication to the OS and graphics), the HTTP server library and the many interfaces to external systems and file formats. In recent years, we started extending the language itself, notably to accomodate expressing syntactic constructions of other languages. This resulted in an extended notion of operators and quasi quotations. SWI-Prolog version~7 takes this one step further by extending the primitive data types of Prolog. This article describes and motivates these extensions.