Design of a Pictorial Program Reference Language.

Abstract : This report covers the work done during the third year of the Program Reference Language (PRL) project. During this year we focused on the problem of developing an adequate means to express the types of queries we had earlier identified as within the province of the PRL. Thus, we studied both the structure of the actual query language and the design of the user interface. The query language on which we concentrated was a pictorial interface designated the PRL Pictorial Language (PRL/PL). The essential idea is that the users build templates to sketch out what an item that satisfied the query would look like. For programs, this means specifying an arrangement of standard program fragments that characterize the desired part of the program. This document will discuss the design and the use of this pictorial language.