Guard and Continuation Optimization for Occurrence Representations of CHR

Constraint Handling Rules (CHR) is a high-level rule-based language extension, commonly embedded in Prolog. We introduce a new occurrence representation of CHR programs, and a new operational semantics for occurrence representations, equivalent to the widely implemented refined operational semantics. The occurrence representation allows in a natural way to express guard and continuation optimizations, which remove redundant guards and eliminate redundant code for subsumed occurrences. These optimizations allow CHR programmers to write self-documented rules with a clear logical reading. We show correctness of both optimizations, present an implementation in the K.U.Leuven CHR compiler, and discuss speedup measurements.

• Type: Conference
• Year: 2005
• Where: ICLP
• Authors: Jon Sneyers, Tom Schrijvers, Bart Demoen
• Keywords: ICLP 2005, Occurrence Representation, Operational Semantics, Optimizations Allow Chr, Programming Languages