User interface development and software environments : the Chiron-1 system

User interface development systems for software environments have to cope with the broad, extensible and dynamic character of such environments, must support internal and external integration, and should enable various software development strategies. The Chiron-1 system adapts and extends key ideas from current research in user interface development systems to address the particular demands of software environments. Important Chiron-1 concepts are: separation of concerns, dynamism, and open architecture. We discuss the requirements on such user interface development systems, present the Chiron-1 architecture and a scenario of its usage, detail the concepts it embodies, and report on its design and prototype implementation

Object-Oriented Programming Language Facilities for Concurrency Control

Concurrent object-oriented programming systems require support for concurrency control, to enforce consistent commitment of changes and to support program-initiated rollback after application-specific failures. We have explored three different concurrency control models -- atomic blocks, serializable transactions, and commit-serializable transactions -- as part of the MELD programming language. We present our designs, discuss certain programming problems and implementation issues, and compare our work on MELD to other concurrent object-based systems

Model for Software Reuse in a Multiparadigm Environment

Computer Scienc

A Specification Environment That Supports the Prototyping of Distributed Systems Using an Object-Oriented Model.

High-speed computer networking, interactive service, and incremental growth for computing are some of the motivations for developing a distributed system. Despite the inherent benefits of a distributed system, the development of software support is more difficult for distributed systems than for sequential systems. In either case, difficulties may arise from the communication problems between two groups of people with different backgrounds trying to formulate requirements for the system. This process depends on feedback and may take many iterations to converge. Customers can usually recognize the features they need when they start using a system, which makes prototyping an important tool in requirement analysis. Many prototyping goals, objectives, and approaches are possible. Executable formal specifications are the most attractive ones. This unification of specification and prototyping by having code generators has advantages of providing consistency and prototyping at higher levels of abstraction. Thus, a methodology for executing the DOSL (Distributed Object-based Specification Language) is defined and a prototype system is developed. DOSL is extended as a new formal distributed object-oriented specification language, DOSL-II. DOSL-II is object-oriented rather than object-based, and includes class, inheritance, simple I/O, stream I/O, concurrent I/O, and new constructs for object communication

LacEDAemon : a programming environment for the multiparadigm language leda

Multiparadigm programming languages are a recent development in the realm of programming languages. A multiparadigm programming language allows the use of multiple, differing programming paradigms without departing from a single, unified linguistic framework. Multiparadigm programming languages are claimed to have benefits to both pedagogy and complex application creation. The beneficial claims of multiparadigm languages have yet to be validated. The availability of a programming environment would encourage and expedite academic and industrial validation. Creating a programming environment is considered an extremely labor intensive activity. Further complications arise from the fact that programming environment creation is an experimental activity: the component mix that best expedites program development in a new programming language cannot be predicted in advance. As a result, few new languages are ever verified in the context of a supportive programming environment. Leda, a unique programming language that includes the functional, imperative, logic and object-oriented paradigms, is at this juncture. This thesis describes the structure of an environment framework that allows for experimental study of the necessary components of a multiparadigm programming language environment. New tools and techniques, as well as changes to traditional tools and techniques are required to allow programmers to abstract effectively across paradigms. This research examines the topic by creating LacEDAemon, a testbed programming environment for the multiparadigm programming language Leda, within the framework of a variety of integrated, cohesive tools. LacEDAemon relies on a hypertool-based toolkit integration framework architecture that affords both loose and tight control integration, as well as data integration, using existing, off-the-shelf tools written in a variety of programming languages. Along with demonstrating the viability of hypertool integration as a low-cost approach for constructing programming environments, LacEDAemon provides a vehicle for: determining an effective multiparadigm programming toolset, studying multiparadigm program design, conducting studies of multiparadigm program visualization, exploring different strategies for software reuse, and examining the merits of conducting all programming activity within the database-centered environment approach. This environment also provides support for investigations in the areas of multiparadigm algorithms, multiparadigm software metrics, and multiparadigm program comprehension. Various techniques for evaluating integrated environments are also applied to LacEDAemon

Generalizing abstractions in form-based visual programming languages : from direct manipulation to static representation

We believe concreteness, direct manipulation and responsiveness in a visual programming language increase its usefulness. However, these characteristics present a challenge in generalizing programs for reuse, especially when concrete examples are used as one way of achieving concreteness. In this thesis, we present a technique to solve this problem by deriving generality automatically through the analysis of logical relationships among concrete program entities from the perspective of a particular computational goal. Use of this technique allows a fully general form-based program with reusable abstractions to be derived from one that was specified in terms of concrete examples and direct manipulation. Also addressed in this thesis is how to statically represent the generalized programs. In general, we address how to design better static representations. A weakness of many interactive visual programming languages is their static representations. Lack of an adequate static representation places a heavy cognitive burden on a VPL's programmers, because they must remember potentially long dynamic sequences of screen displays in order to understand a previously-written program. However, although this problem is widely acknowledged, research on how to design better static representations for interactive VPLs is still in its infancy. Building upon the cognitive dimensions developed for programming languages by cognitive psychologists Green and others, we have developed a set of concrete benchmarks for VPL designers to use when designing new static representations. These benchmarks provide design-time information that can be used to improve a VPL's static representation