CORAL - Control, Relations and Logic

Abstract

CORAL is a modular declarative query language/programming language that supports general Horn clauses with complex terms, set-grouping, aggregation, negation, and relations with tuples that contain (universally quantified) variables. Support for persistent relations is provided by using the EXODUS storage manager. A unique feature of CORAL is that it provides a wide range of evaluation strategies and allows users to --- optionally --- tailor execution of a program through high-level annotations. A CORAL program is organized as a collection of modules, and this structure is used as the basis for expressing control choices. CORAL has an interface to C++, and uses the class structure of C++ to provide extensibility. Finally, CORAL supports a command sublanguage, in which statements are evaluated in a user-specified order. The statements can be queries, updates, production-system style rules, or any command that can be typed in at the CORAL system prompt. This work was supported by a Da...