Generic programming

Abstract

Early generic concepts in programming languages were mixed-type arithmetic (e.g., “+” used with any combination of fixed- and floating-point numbers) and “print” functions which could be applied to any of a language's objects. Generic concepts reduce the number of terms which must be remembered and permit considerable condensation of language design. Three different paths in the development of generic-concept languages have been followed by APL, Algol 68, and object-oriented languages such as SIMULA 67 and Smalltalk. APL was the earliest and one of the most interesting applications of generic-concept methods, but now makes the weakest use of these ideas.My talk will use slides and movies to show how the message-object programming system Smalltalk makes use of generic concepts embedded in class descriptions to give rise to a wide variety of simply programmed dynamic simulations including graphic animation, music synthesis, document layout and retrieval, and APL-like calculation features. Many of these systems have been brought to life by child and adult novice programmers.A short list of references is given for those wishing more introductory information about Smalltalk.