System design of a grammar-programmable high-level language machine

Abstract

An architectural concept called Grammar-Programming is introduced which allows computers to be constructed that can directly execute a variety of high-level languages. Representing an intermediate level between the basic hardware/firmware functions of ordinary computers and the software operations of language translators, it is shown how grammar-programs can be constructed which specify the syntax and semantics of various programming languages. The Grammar-Programmable Machine (GPM) then uses these specifications to process directly the users' high-level language programs. In the Ph.D. dissertation* upon which this abstract is based, a model is first developed for representing the syntactic and semantic characteristics of context-free language generators, and an automaton called a Syntax Network (SN) is constructed. Next a simple, statement-directed language is introduced to express the states of the syntax network and to define the actual grammar-programming language. A simulator is then implemented which is used to test the grammar-programs written for ALGOL and SNOBOL. Finally, the architectural organization for the Grammar-Programmable Machine is described at the register-transfer level. By taking advantage of its intermediate position between software compilation and hardware interpretation of high-level languages, the Grammar-Programmable Machine is able to emphasize the best features of both techniques and to achieve a potential that neither can reach individually.