Domain-specific language design requires feature descriptions

A domain-specific language (DSL) provides a notation tailored towards an application domain and is based on the relevant concepts and features of that domain. As such, a DSL is a means to describe and generate members of a family of programs in the domain. A prerequisite for the design of a DSL is a detailed analysis and structuring of the application domain.Graphical feature diagrams have been proposed to organize the dependencies between such features, and to indicate which ones are common to all family members and which ones vary. In this paper, we study feature diagrams in more details, as well as their relationship to domain-specific languages. We propose the Feature Description Language (FDL), a textual language to describe features.We explore automated manipulation of feature descriptions such as normalization, expansion to disjunctive normal form, variability computation and constraint satisfaction. Feature descriptions can be directly mapped to UML diagrams which in their turn can be used for Java code generation. The value of FDL is assessed via a case study in the use and expressiveness of feature descriptions for the area of documentation generators

Little languages : little maintenance?

So-called little, or domain-specific languages (DSLs), have the potential to make software maintenance simpler: domain-experts can directly use the DSL to make required routine modifications. At the negative side, however, more substantial changes may become more difficult: such changes may involve altering the domain-specific language. This will require compiler technology knowledge, which not every commercial enterprise has easily available. Based on experience taken from industrial practice, we discuss the role of DSLs in software maintenance, the dangers introduced by using them, and techniques for controlling the risks involved

Building program understanding tools using visitor combinators

Program understanding tools manipulate program representations, such as abstract syntax trees, control-flow graphs, or data-flow graphs. This paper deals with the use of visitor combinators to conduct such manipulations. Visitor combinators are an extension of the well-known visitor design pattern. They are small, reusable classes that carry out specific visiting steps. They can be composed in different constellations to build more complex visitors. We evaluate the expressiveness, reusability, ease of development, and applicability of visitor combinators to the construction of program understanding tools. To that end, we conduct a case study in the use of visitor combinators for control-flow analysis and visualization as used in a commercial Cobol program understanding tool

An empirical study into COBOL type inferencing

AbstractIn a typical COBOL program, the data division consists of 50% of the lines of code. Automatic type inference can help to understand the large collections of variable declarations contained therein, showing how variables are related based on their actual usage. The most problematic aspect of type inference is pollution, the phenomenon that types become too large, and contain variables that intuitively should not belong to the same type. The aim of the paper is to provide empirical evidence for the hypothesis that the use of subtyping is an effective way for dealing with pollution. The main results include a tool set to carry out type inference experiments, a suite of metrics characterizing type inference outcomes, and the experimental observation that only one instance of pollution occurs in the case study conducted

Domain-specific language design requires feature descriptions

A domain-specific language (DSL) provides a notation tailored towards an application domain and is based on the relevant concepts and features of that domain. As such, a DSL is a means to describe and generate members of a family of programs in the domain. A prerequisite for the design of a DSL is a detailed analysis and structuring of the application domain.Graphical feature diagrams have been proposed to organize the dependencies between such features, and to indicate which ones are common to all family members and which ones vary. In this paper, we study feature diagrams in more details, as well as their relationship to domain-specific languages. We propose the Feature Description Language (FDL), a textual language to describe features.We explore automated manipulation of feature descriptions such as normalization, expansion to disjunctive normal form, variability computation and constraint satisfaction. Feature descriptions can be directly mapped to UML diagrams which in their turn can be used for Java code generation. The value of FDL is assessed via a case study in the use and expressiveness of feature descriptions for the area of documentation generators

Program plan recognition for year 2000 tools

There are many commercial tools that address various aspects of the Year 2000 problem. None of these tools, however, make any documented use of plan-based techniques for automated concept recovery. This implies a general perception that plan-based techniques is not useful for this problem. This paper argues that this perception is incorrect and these techniques are in fact mature enough to make a significant contribution. In particular, we show representative code fragments illustrating ``Year 2000'' problems, discuss the problems inherent in recognizing the higher level concepts these fragments implement using pattern-based and rule-based techniques, demonstrate that they can be represented in a programming plan framework, and present some initial experimental evidence that suggests that current algorithms can locate these plans in linear time. Finally, we discuss several ways to integrate plan-based techniques with existing Year 2000 tools