Automatic Data Structure Choice in a Language of Very High Level

Abstract

SETL is a set-theoretically oriented language of very high level whose repertoire of semantic objects includes finite sets, ordered n-tuples, and sets of ordered n-tuples useable as mappings. This paper sets forth techniques for the logical analysis and optimization of SETL programs. The techniques described allow relations of inclusion and membership to be established, the domains and ranges of (tabulated) mappings to be estimated from above and below, and the singlevaluedness of (tabulated) mappings to be proved. Once facts of this kind have been established, automatic choice of data structures becomes possible. The methods employed are based upon, and extend, known techniques of data-flow analysis.