A Display Oriented Programmer's Assistant

Abstract

This pa per continues a nd extends previous work by the auth or in develo ping sys tem s which provide the user with various forms of exp li cit and implicit assistance, and in ge nera l cooperate with the user in the development of his programs. The sys tem described in this paper makes extensi ve use of a bit map display and pointing device (a mouse) to signif ica ntl y enrich the user's interactions with the sys tem, and to provide capabilities not possible with terminals that essentially emulate hard copy devices. For example, a ny te xt th at is displ ayed on the screen can be pointed at a nd treated as input, exactly as though it were typed, i.e ., the user can say use this expression or that value, and th en simpl y point. The use r views his programming environment through a collection of displ ay windows, each of whi ch corresponds to a diff erent t as k or co ntext. The user can manipulate th e windows, or th e co ntents of a particular window, by a combination of keyboard inputs or pointing opera ti ons. The technique of using different windows for different ta sks ma kes it easy for the user to nl3nage several sim ultaneo us t as ks and contexts, e.g., defi ning programs, testing program s, editing, asking th e system for ass istance, se ndin g and receiving messages, etc. and to sw itch back and forth between the se tas ks at his convenience.