SETL is a very-high-level programming language supporting set-theoretic syntax and semantics.It allows algorithms to be programmed rapidly and succinctly without requiring data-structure declarations to be supplied.Such declarations can be manually specified later, without recoding the program, to improve the efficiency of program execution.We describe a new technique for automatic selection of appropriate data representations during compile time for programs with omitted declarations and present an efficient data representation selection algorithm, whose complexity is comparable with those of the fastest known general data-flow algorithms of Tarjan and Reif.

SETL is a very high level programming language supporting set theoretical syntax and semantics. It allows algorithms to be programmed rapidly and succinctly without requiring data structure declarations to be supplied, though such declarations can be manually specified later, without recoding the program, to improve the efficiency of program execution. We describe a new technique for automatic selection of appropriate data representations during compile-time for undeclared, or partially declared programs,and present an efficient data structure selection algorithm, whose complexity is comparable with those of the fastest known general data-flow algorithms of Tarjan [TA2] and Reif [RE].

“Pure” SETL is a language of very high level allowing algorithms to be programmed rapidly and succintly. SETL's representation sublanguage adds a system of declarations which allow the user of the language to control the data structures that will be used to implement an algorithm which has already been written in pure SETL, so as to improve its efficiency. Ideally no rewriting of the algorithm should be necessary. The facilities provided by the representation sublanguage and the run-time data structures that it can generate are described; based on this a heuristic which uses some of the methods of global program analysis and which should be capable of selecting an acceptably efficient representation automatically is given.