PECAN: Program Development Systems that Support Multiple Views

Reviewer: Robert Keith Sawyer

This paper is a report on development in progress on the PECAN programmer support environment. PECAN, a programmer development environment which supports multiple views of the user's program, is designed to make use of the new generation of high-resolution personal computers now available, such as the Apollo and Sun 68000-based workstations. PECAN is a collection of features, some original, and some derived from earlier work. Most of the features currently implemented are already available on high-end systems such as Symbolics LISP machines. These features are interactive syntactic error feedback, unlimited undo in the editor, various menu types, incremental compiling, and multiple window display. The PECAN design is meant to support all programming languages; however, the paper gives no indication that sophisticated program and data abstractions have been used. It seems that the system will support only linear, algebraic languages. While the overall project goals are ambitious, this report seems premature. The only language supported is PASCAL. Only two program views are implemented: a syntax-directed editor, and a Nassi-Schneiderman flow-chart view (read-only). Thus, editing must be done in the text editor. Even this editor will only reformat based on internal representation for program units which fit on one line of the editor. Algorithmic templates are provided, but no indication of their scope is given in the paper. In sum, while this project may be valuable to PASCAL developers using an Apollo system at Brown, there appears to be no real contribution to the theory of program development environments. Also, there is little of value here which could not be found in earlier work.