GenVoca generators synthesize software systems by composing components from reuse libraries. GenVoca components are designed to export and import standardized interfaces, and thus be plugcompatible, interchangeable, and interoperable with other components. In this paper, we examine two different but important issues in software system synthesis. First, not all syntactically correct compositions of components are semantically correct. We present simple, efficient, and domainindependent algorithms for validating compositions of GenVoca components. Second, components that export and import immutable interfaces are too restrictive for software system synthesis. We show that the interfaces and bodies of GenVoca components are subjective, i.e., they mutate and enlarge upon instantiation. This mutability enables software systems with customized interfaces to be composed from components with “standardized ” interfaces. 1

People benefit from tightly integrated systems that can be designed, realized and evolved affordably. Unfortunately, common software design methods do not easily accommodate requirements for tightly integrated systems. Indeed, when used to meet such requirements, common methods tend to yield unnecessarily complex structures that complicate design and realization and that inhibit subsequent evolution. After substantiating this claim, I present the mediator method as a solution. This method combines behavioral entity-relationship (ER) modeling for design with a mediator approach to implementation. The mediator method is better than common methods for designing, realizing, and evolving many integrated systems. I support this claim both by rational argument from simplifying models and by careful...

iented programming is an enhancement of object-oriented programming that allows decentralized class definition. An application developer who needs new operations associated with classes can implement them him/herself, not by editing existing code for the classes, but as a separate collection of class definitions called a subject. Multiple subjects can be composed to yield a complete suite of applications; class definitions within the subjects will be combined so as to satisfy the needs of all the applications in the suite. A simple example is shown in Figure 1. Neither source code access nor recompilation are required to perform this composition, allowing extension and composition of object-code-only applications. Without eliminating the advantages of encapsulation, this approach eliminates the need for class ownership, and hence for the second, more serious kind of negotiation noted above. An application developer can write all the code needed for the application, irrespective of whic

1 The tenet of subjectivity is that no single interface can adequately describe any object; interfaces to the same object will vary among different applications. Thus, objects with standardized interfaces seem too brittle a concept to meet the demands of a wide variety of applications. Yet, objects with standardized interfaces is a central idea in domain modeling and software generation. Standard interfaces make objects plug-compatible and interchangeable, and it is this feature that is exploited by generators to synthesize high-performance, domain-specific software systems. Interestingly, generated systems have customized interfaces that can be quite different from the interfaces of their constituent objects. In this paper, we reconcile this apparent contradiction by showing that the objects (components) in the GenVoca model of software generation are not typical software modules; their interfaces and bodies mutate upon instantiation to a "standard" that is application-dependent. 1 ...

The tenet of subjectivity is that no single interface can adequately describe any object; interfaces to the same object will vary among different applications. Thus, objects with standardized interfaces seems too brittle a concept to meet the demands of a wide variety of applications. Yet, objects with standardized interfaces is a central idea in domain modeling. Domain models are the basis for generators that synthesize high-performance, domain-specific software systems with customized interfaces. In this paper, we reconcile this apparent contradiction by showing that objects (i.e., components) of generator libraries are not typical software modules; their interfaces (and bodies) actually mutate upon instantiation to a "standard" that is application-dependent. 1 Introduction It is well-known in photography that there is no single perspective from which all aspects of an object can be viewed; depending on the perspective taken, some aspects may be completely hidden while others might...

Integrated Computer Aided Software Engineering (CASE) tool environments are essential to improve productivity of software development. To provide portable integrated tool environments, Portable Common Tool Environment (PCTE) was introduced. PCTE is a standard for Software Engineering Environments (SEEs). PCTE provides a number of SEE repository services as a form of public tool interface for CASE tools. Object Oriented Database Management Systems (OODBMS) is considered as the next generation DBMSs. OODBMSs can manipulate complex data, such as SEE data, which cannot be managed by traditional DBMSs. ODMG-93 is a standard OODBMS interface proposed by Object Database Management Group (ODMG). The goal of this paper is to compare the two standards, PCTE and ODMG-93. 1 Introduction In the future, it will be more important for software engineers to use Computer Aided Software Engineering (CASE) tools. But, CASE tools do not always improve productivity of software development. To improve soft...

This report will go into depth about these and related issues. It will focus on the needs of WSRC and, in so doing, will enable the scope of the repository to be reduced somewhat. For example, one goal is to minimize the impact on present application development practices; consequentially, WSRC may not wish to provide version control as a repository service. Another goal is to maximize the self-reliance of end-users, so the repository should be very user-friendly and provide clear descriptions of the elements stored in the repository. The ability to browse the repository and to perform keyword searches should allow end-users to find what they are looking for. Once found, the descriptions within the repository will get them started. The repository will also guide them to more detailed information (e.g., in on-line help, in on-line documentation, or even in off-line printed manuals). - 5 - 1. Introduction

Object-Oriented technology is often described in terms of an interwoven troika of themes: encapsulation, polymorphism, and inheritance. But these themes are firmly tied with the concept of iden-tity. If object-oriented technology is to be successfully scaled from the development of independent applica-tions to development of integrated suites of applica-tions, it must relax its emphasis on the objecf. The technology must recognize more directly that a mul-tiplicity of subjective views delocalizes the concept of object, and must emphasize more the binding concept of identity to tie them together. This paper explores this shift to a style of object-oriented technology that emphasizes the subjective views: Subject-Oriented Programming. 1.

SPECIFICATION - NATO Unclassified - (8) Tool integration shall be understood as the relationship of the tool to the data in the repository. Tool coordination shall be understood as relationships established between running tools using message passing capabilities. (9) As shown in Figure 43 and stated in the ECMA/NIST Reference Model (RM) (see [35] on page 182), the tool integration and coordination issues with respect to a SEE 1 , can be seen from various perspectives, quoting the RM: (10) From the user's perspective. (11) An integrated SEE provides a common view into the system. The entire environment operates as one consistent tool rather than a collection of separately invoked or distinct functions. For example, this means common access to data or common presentation (e.g., windows, mouse, control commands, error messages, tool invocation) of the services that the user initiates. (12) From the tool developer's perspective (13) An integrated SEE provides a consistent interfac...

this document.