A dynamically self-adjusting structured editor

摘要

Two major characteristics shared by most program editors are that they are static, as they operate within a single framework of a full program text, and that they are strictly language based. These characteristics are considered to be less than desirable, as they appear to restrict the development of production software. As a solution, a new kind of structured editor, based on program fragments, is proposed in this paper. This kind of editor is dynamic, as it is driven by the types of different fragments, called fragtypes. As a fragment evolves during an editing session, its fragtype can change depending on the user operations. Such changes trigger off automatic adjustments in the editor capabilities. Fragtypes range from that of small granularity objects, such as an identifier, to that of large granularity objects, such as a subsystem. The dynamic nature of the editor, together with the wide range of fragtypes provided, appear to be more suitable for serious programming. This editor is a subject of current research in the context of the MUPE-2 project, at McGill, which aims to design an integrated programming environment for Modula-2. However, many ideas from this paper can also be applied to the design of environments for other algorithmic languages.