Fragtypes: a basis for programming environments

The author introduces a novel basis for programming environments that encourages development of software in fragments of various types, called fragtypes. Fragtypes range from a simple expression type to a complete subsystem type. As a result, they are suited to the development of software in an enlarged scope that includes both programming in the small and programming in the large. The author shows how proposed operations on fragtypes can achieve unusual effects on the software development process. Fragtypes and their associated construction rules form the basis of the programming environment MUPE-2, which is currently under development at McGill University. The target and the implementation language of this environment is the programming language Modula-2