A highly‐structured interpreter for a SNOBOL4 subset
Frank G. Pagan · Software Practice and Experience · 1979
Abstract A highly‐structured and conceptually simple processor, written in Algol 68, for a basic but useful subset of SNOBOL4 is presented. It provides a significant, large‐scale demonstration of a particular methodology for constructing ‘master’, machine‐independent implementations of programming languages. The processor is closely related to a formal operational definition of the SNOBOL4 subset in that it incorporates an abstract machine, a high‐level abstract syntax (in the form of mutually recursive mode definitions) for the internal form of programs, and a set of mutually recursive interpretation procedures for programs in this internal form. The various aspects of the processor are documented in some detail. The experience of testing the processor is briefly discussed.