A metalanguage to express human guidance for program transformation

A metalanguage, TrapML, is proposed. It has the ability to describe the syntax of object languages, transformation rules, and strategies. An abstract transformational programming system NDTPS is constructed to implement the language. It provides various supports for transformation activities, but does not depend on the syntax of object languages, transformation rules, and strategies. Metaprograms are used to equip the system, forming a specific transformation system. Some experiments with metaprogramming have been carried out such as the construction of a transformation system for optimization of J. Backus´s FP programs, the description of the synthesis process of divide-and-conquer algorithms from pre/postconditions, an interpreter of equational logic, and a synthesis system which derived linear recursive FP programs from input/output examples