Transformations and Abstract Presentations in a Language Development Environment

A syntax-directed editing environment intended for development of artificial languages, e.g. programming languages, specification languages, and grammar definition languages, is presented. Various applications of a simple, syntactic transformation facility is central to the work. There is a description of how most syntax-directed editing operations can be implemented and understood as transformations. It is furthermore demonstrated how documents, which are represented as abstract syntax trees, can be kept consistent with a grammar that is under development. A multi-formalism transformation technique is also described. Abstract presentation of documents on a screen is another central topic. Two simple presentation formalisms that allow documents to be shown as trees and graphs are proposed. As a basis for the whole work, a new formalism for description of context-free languages has been worked out. The formalism is based on generalization/specialization hierarchies of syntax domains.