Higher-Order Attribute Semantics of Flat Declarative Languages

A technique is described that provides a convenient instrument for implementation of semantics of simple declarative languages called flat languages. Semantics of a specification is defined in the paper as a set of programs derivable for solvable goals. We introduce higher-order attribute models that include more control information than conventional attribute models and explain the algorithm for dynamic evaluation of attributes on these models. A visual tool CoCoViLa is briefly described as an instrument for implementing attribute semantics of flat languages

Constraints in NUT

NUT is a programming system for knowledge-based programming with facilities for automatic program synthesis. The system allows to specify computational problems in OO style. Concepts and objects can be treated in NUT as functional constraint networks. Constraint satisfaction problems are solved using algorithms for automatic program synthesis described earlier for the PRIZ system. 1.1 Introduction The NUT system is the most advanced representative of the family of programming systems called PRIZ. This family includes systems PRIZ ES, Solver, MicroPRIZ, ExpertPRIZ, NUT etc., which have been developed in the last 20 years in the Institute of Cybernetics of the Estonian Academy of Sciences. All these systems support a knowledge-based programming style and they have been successfully used to solve engineering problems as well as in scientific investigations of AI. The NUT language was outlined as an extension of an object-oriented programming language with features of automatic program sy..