A Structural View of PL/I

Abstract

This tutorial paper is presented at an intermediate level, which assumes that the reader already has either some elementary knowledge of PL/I or a more general familiarity with other high level languages. An attempt is made to break fresh ground by addressing a question concerning the design philosophy of PL/I, namely whether it is possible for the more experienced programmer to grasp the deeper structure and achieve complete mastery of a language wlth such broad scope. (It is not concerned with showing how easily parts of the language may be used for simple applications, although several introductory texts are cited.) The method of the exposition is first to dispose of certain preprocesses which may be performed, and then to organize the major part of the material under two heads, static aspects and dynamic aspects. The static aspects are those essentially related to inspection rather than executmn of a program; the dynamic part of the discussion outlines the semantics in terms of the internal storage, external storage, and flow of control in a conceptual PL/I machine. Every statement and type of object in the language is given a place in this scheme. © 1970, ACM. All rights reserved.