LCS/AI Lab Timeline

Language features from APT to AED (1957)

APT Language naturally spawned features later found in general-purpose languages and software systems. "Macroinstructions" built move sequences to safely orient toward and PLUNGE into a workpiece, e.g.. Surfaces were both physical and logical in tool-path specification and cut calculation, so the programming language was "object oriented" -- with no room for "ref" or "pointers" -- only meaningful NAMES. To define geometry, NESTED assignments of Names TO Objects arising in ruler-and-compass-like constructions, presaged AED's "phrase substitution" -- allowing any expression of the CORRECT (OBJECT-)type to fit anywhere. (I.e. it's the "where"s that have the Correctness constraints! Only they allow and impose structure! N-component elements "cluster 'where's".) Names and expressions take on the type of their objects (that they join or create), so contrary to today's OO talk: Classes or types do not "have" operations at all; they have operators. As in mathematics, it is the OPERATORs OF a type that provide the OPERATIONs ON Objects of that type to yield a Result Object.

References:
Ross APT History paper.

Reported By:
Doug Ross