Gödel : an Interactive Incremental Logic Programming Environment

SUMMARY This paper describes Gödel, an interactive incremental logic programming environment. Gödel supports programming in "standard" Prolog. However, Gödel uses its environment to superimpose a module structure and an inheritance typing system which can be used to support modern software engineering strategies. In addition, Gödel presents the user with a uniform user interface for browsing, editing, executing and debugging which simplifies context switches between these activities and reports errors as they occur. The most important and novel aspects of Gödel are its introduction of software engineering support without changing the language, its incremental translation of clauses to a persistent clause base as the clauses are entered, its efficient object-oriented inference engine written in Smalltalk-80 and its primitive clauses that provide a seamless interface between Prolog and Smalltalk-80.