PL/1 (Programming Languages 1)
History
(Programming Language 1) A high-level IBM programming language introduced in 1964 with the System/360 series, developed by George Radin of IBM in 1964. Originally named (NPL) and Fortran VI. It was designed to combine features of and eventually supplant COBOL and FORTRAN, which never happened. A PL/I program is made up of procedures (modules) that can be compiled independently. There is always a main procedure and zero or more additional ones. Functions, which pass arguments back and forth, are also provided.
PL/I is also a general-purpose programming language, which is used for solving problems in a variety of fields such as commerce, science (including mathematics, physics, chemistry), engineering (including civil, electrical, aeronautics), medicine, and so on. It can be used for system programming, and the facilities are such that it is rarely if ever necessary to resort to machine-language or assembly-language programming to solve problems. PL/I can be used for commercial data processing, numerical methods, text processing, list processing, system programming, real-time system programming, and picture file processing, to mention a few specific applications.
PL/I have outstanding facilities for commercial and business use. It has more power than Pascal, Fortran 95, BASIC, C, and COBOL, and has comparable facilities to Ada. The main areas where PL/I is superior include interrupt handling, the built-in debugging aids, the macro processor facilities, string-handling, and input-output (see below for a link to a summary). The language has good documenting and self-documenting facilities; programs are easy to read and to understand. It bears some resemblance to Fortran and BASIC. The language is suitable for beginners, as well as for anyone wanting to become a professional.
Significant Language Features
PL/1 had the following significant language features:
• PL/I is completely free form and has no reserved
References: Rich, Robert P. Internal Sorting Methods Illustrated with PL/I Programs. Englewood Cliffs: Prentice-Hall, 1972. Sebesta, Robert W. Concepts of Programming Languages. 3rd ed. Menlo Park: Addison-Wesley, 1996.