Refinements and multi-dimensional separation of concerns

Abstract

1Step-wise refinement (SWR) asserts that complex programs can be derived from simple programs by progressively adding features. The length of a program specification is the number of features that the program has. Critical to the scalability of SWR are multi-dimensional models that separate orthogonal feature sets. Let n be the dimensionality of a model and k be the number of features along a dimension. We show program specifications that could be O(k n ) features long have short and easy-to-understand specifications of length O(kn) when multi-dimensional models are used. We present new examples of multidimensional models: a micro example of a product-line (whose programs are 30 lines of code) and isomorphic macro examples (whose programs exceed 30K lines of code). Our work provides strong evidence that SWR scales to synthesis of large systems.

Feature refactoring a multi-representation program into a product line

“…We repeated (5) and (6) to remove incrementally all features from extra that we identified in the last section. The final version of extra was empty -it contained no files.…”

Feature-oriented programming and the AHEAD tool suite

“…We have shown program specifications that could be O(k n ) features long have short and easy to understand specifications of length O(kn), where n is the number of dimensions and k is the number of features per dimension [2]. That is, systems with exponential complexity have quadratic-length specifications.…”

“…An application is defined by a composition of such operators; The AHEAD Tool Suite (ATS) is a set of Java-based tools that support program development in AHEAD. ATS is being used in the construction of fire support simulators for the U.S. Army [3] and in the synthesis of ATS itself [2]. That is, ATS tools have been bootstrapped: each ATS tool has its own AHEAD expression and the tool itself is synthesized from this expression.…”

Feature Modularity in Software Product Lines

“…An FOP model of a product-line is an algebra: base programs are constants and program extensions are functions (that add a specified feature to an input program). Program designs are expressions -compositions of functions and constants -that are amenable to optimization and analysis.FOP is at the confluence of many different areas of research: product lines, aspect oriented programming, metaprogramming (program design as a computation), layered designs [1], declarative domain specific languages [2], automatic programming (i.e., mapping a declarative specification of a program to an efficient implementation) [3], and multidimensional separation of concerns [5].This tutorial reviews core results on FOP:• compositional models of software development and program synthesis [6],• models and tools for synthesizing code and non-code artifacts [6],• formal representations of feature models and automatic algorithms for verifying feature compositions [2],• relationships between metaprogramming, product lines, and model driven engineering (MDE) [7], and • tool demonstrations of the above. …”

“…FOP is at the confluence of many different areas of research: product lines, aspect oriented programming, metaprogramming (program design as a computation), layered designs [1], declarative domain specific languages [2], automatic programming (i.e., mapping a declarative specification of a program to an efficient implementation) [3], and multidimensional separation of concerns [5].…”