William M. Schell

Bio: William M. Schell is an academic researcher from Bell Labs. The author has contributed to research in topics: Abstract syntax & Executable. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

Experiences with an environment generation system

Abstract: The authors report on research experience using the Gandalf environment generation system as a prototyping vehicle for the Inscape environment. A Gandalf-based environment consists of four parts: a structure editor kernel, which is simply linked into each executable, a set of grammar tables describing the language to the kernel in terms of its abstract syntax, one or more concrete syntax views, and a collection of action routines written in the extension language, ARL. Positive aspects of the research included experimentation, incremental evolution, multiple views, the coupling of semantic and editing actions, and the use of domain-specific facilities. Negative aspects consisted primarily of problems with presentation and object management. >

Software evolution and 'light' semantics

Abstract: The motivation for Inscape came from my experience as a programmer, designer and architect There were two major (and inter-related) problems that I encountered while building software systems where I had to use components built by other people: the pieces often did not fit when I put them together and changing code often produced surprising and unexpected results The first problem was due primarily to the informality and often incompleteness of component interfaces The second problem was due ultimately to the complexity of the software and an inability to foresee or determine the consequences of changes These problems result from three essential and intertwined properties of building software systems: composition, evolution and complexity In coming to grips with the problem of composition, using formal interface specifications is the obvious choice Enhancing the syntactic interfaces with semantic information is one way of expressing the intent of the interface provider and enabling the user to have all the information necessary to its correct and effective use How to attack the problem of evolution is not as obvious The approach I took in the Inscape experiment was to use the specifications constructively in order to determine and maintain semantic dependencies Keeping track semantically as to how the interfaces are used is the analog of expressing the interface creator's intent: it is capturing the users intent Given that both interfaces and implementations evolve, keeping track of the dependencies enables the environment to help in understanding the effects of changes and where those effects take place

Software evolution and “light” semantics (extended abstract)

Abstract: The first problem was due primarily to the informality and often incompleteness of component interfaces. The second problem .was due ultimately to the complexity of the software and an inability to foresee or determine the consequences of changes. These problems result from three essential [l] and intertwined properties of building software systems: composition, evolution [2] [‘i’] and complexity [5].