This paper introduces an efficient incremental LL(1) parsing algorithm for use in language-based editors that use the structure recognition approach. It is designed to parse user input at intervals of very small granularity and to limit the amount of incremental parsing needed when changes are made internal to the editing buffer. The algorithm uses the editing focus as a guide in restricting parsing. It has been implemented in the Fred language-based editor.>

This paper presents our experience building an extendible software development environment using the object-oriented paradigm. We have found that object instances provide a natural way to model program constructs, and to capture complex relationships between different aspects of a software system. The object-oriented paradigm can be efficiently implemented on standard hardware and software, and provides some degree of extendibility without requiring major modifications to the existing implementation.

At the core of any sophisticated software development and maintenance environment is a large mass of complex data. The data (the central data of the environment) is composed of smaller sets of data that can be related in complicated and often subtle ways. The user or developer of the environment will be more effective if they are able to deal with conceptual slices, or views, of the large, complex structure. This paper presents an architectural building block for object-based software environments based on the views concept. The building block allows the construction of global abstractions that describe unified behavior of large sets of objects. The basis of the architecture relies on extending the object-oriented paradigm in three steps: (1) defining multiple interfaces in object classes; (2) controlling visibility of instance variables; and (3) allowing multiple copies of an instance variable to occur within an object instance. This paper focuses on the technical aspects of the views approach.