From Standard to Non-Standard Semantics by Semantics Modifiers

Abstract

An approach for systematically modifying the semantics of programming languages by semantics modifiers is described. Semantics modifiers are a class of programs that allow the development of general and reusable "semantics components". Language independence is achieved through the interpretive approach: an interpreter serves as a mediator between the new language and the language for which the non-standard semantics was implemented. Inverse computation, equivalence transformation and neighborhood analysis are shown to be semantics modifiers. Experiments with these modifiers show the computational feasibility of this approach. Seven modifier projections are given which allow the efficient implementation of non-standard interpreters and non-standard compilers by program specialization or other powerful program transformation methods.

Transforming interpreters into inverse interpreters by partial evaluation

“…The Universal Resolving Algorithm used for the experiments in this paper deals with the general case. A detailed exposition of the concepts presented here can be found in the publications [1,2,3]. The notation is adapted from [17].…”

“…It is represented by a variable (Xe1) where the restriction on the domain of the variable is empty (∅). The output list is given ( [7,6,5,4,3,2,1]). This information forms a class:…”

“…basis for semantics-modifiers [2]. URA was applied interpretively to interpreters for several imperative languages [3,4].…”

“…To explain how program specialization may be useful in this context, we will first define a semantics modifier for inverse computation. Let us abstract the interpreter intQ from the construction in (4) and define a new program invmod which we call a semantics modifier for inverse computation [2] (short: inversion modifier).…”

“…Other schemes for optimizing semantics modifiers exist [2,3]. For example, we may also produce inverse programs by these techniques.…”