Rule-Based Invasive Software Composition with Strategic Port-Graph Rewriting (RISCOS)

软件构件的重用对于降低软件开发过程中的成本具有重要意义。对于灵活的重用，适当的组件模型、组合技术和语言是重要的(所谓的组合系统)。一种非常吸引人的重用形式是组件的横切组合，即一个组件分布在一组其他组件上(编织)。编织可以用于复杂的重用场景并简化产品线的组织，因为横切方面和可选功能可以与产品线的核心分开管理。然而，对于这种形式的分布式合成，必须构建特定于语言的编织工具(编织器)，这需要花费大量的努力。开发编织器工具的简单方法将是可取的，例如，借助声明性语言。对于任意文本和图形语言的合成系统的开发，可以使用侵入性软件合成(ISC)。此外，还可以使用ISC开发织造工具，为此必须编写合成程序。为此，使用图形重写系统会很有趣，因为它们具有声明性语义并提供高度自动化。我们在以前的工作中已经证明了这是可能的。然而，有两个问题：第一，在编织过程中，图重写系统的规则(关键对)之间会出现冲突，需要识别这些规则(冲突识别)。其次，必须通过为所有关键对指定适当的选择策略来避免冲突。因此，到目前为止，需要使用编程的图形重写系统，这些系统并不完全是声明性的。该项目的目标是简化程序、模型和文档的可靠编织工具的构建。为了简化编织，将使用端口图重写，这是一种相当新颖的方法，适用于对组件和组合进行建模。为了识别冲突，将使用参考属性语法，从而实现规则之间的自动相关性分析。为了避免冲突，将调查端口图重写的策略语言在多大程度上可以用于指定选择策略。为了能够将该技术用于任意编程、建模和文档语言，应使用侵入式软件组合作为基础，以便所有组合和编织都是类型安全的，并尊重静态语义规则。

The reuse of software components is important for the reduction of the costs in the software development process. For flexible reuse, proper component models, composition techniques and languages are important (so-called composition systems). A quite attractive form of reuse is the crosscutting composition of components, i.e., the distribution of a component over a set of other components (weaving). Weaving can be used for complex reuse scenarios and simplifies the organization of product lines, because crosscutting aspects and optional functionality can be managed separately from the core of a product line. However, for this form of distributing composition, language-specific weaving tools (weavers) have to be built, and this costs a lot of effort. A simple way to develop weaver tools would be desirable, e.g., with the help of declarative languages. For the development of composition systems for arbitrary textual and graphic languages, invasive software composition (ISC) can be employed. Also weaving tools can be developed with ISC, for which a composition program has to be written. For this purpose, it would be interesting to use graph rewrite systems, because they have a declarative semantics and offer a high degree of automation. We have shown in previous work that this is possible. However, there are two problems: Firstly, during weaving conflicts arise between the rules of the graph rewrite system (critical pairs), which have to be recognized (conflict recognition). Secondly, the conflicts have to be avoided by specifying an appropriate selection strategy for all critical pairs. So far, it is therefore required to use programmed graph rewrite systems, which are not fully declarative. The objective of the project is to simplify the construction of reliable weaving tools for programs, models, and documents. To simplify weaving, port-graph rewriting shall be employed, a rather novel approach, which is appropriate to model components and compositions. For the recognition of conflicts, reference attribute grammars will be used, which allow for automated dependency analyses between rules. For the avoidance of conflicts, strategy languages from port-graph rewriting will be investigated in how far they can be used to specify selection strategies. To be able to use the technology for arbitrary programming, modeling, and document languages, invasive software composition shall be used as foundation, so that all compositions and weavings are type-safe and respect the rules of static semantics.