一种面向图形化建模语言表示法的元模型

对于图形化的建模语言,为定义其表示法一般需要解决3个问题:如何定义每个建模元素的图形符号,如何定义图形符号之间的位置关系以及如何将表示法映射到抽象语法.为了方便进行模型转换和代码生成,还需要使用模型化的方式描述建模语言的表示法.通过对UML及其语言家族中的表示法进行总结、分析和归纳,提出了一种表示法定义元模型(notation definition metamodel,简称NDM).针对定义表示法所面临的3个问题,NDM被分成基本图元及其布局、基本位置关系和抽象语法桥三部分.使用NDM定义好的表示法模型还可以通过代码生成技术生成可使用的源代码.将NDM与其他几种定义表示法的方法进行了比较,结果表明,NDM与其他方法相比具有优势.NDM已经在元建模工具PKU MetaModeler中实现.介绍了NDM在实际应用中的几个案例.

A Metamodel for the Notation of Graphical Modeling Languages

For graphical modeling languages,there are three problems on the notation definition:How to define graphical symbols for modeling elements;How to define the location relations between symbols;How to map the symbols and the location relations to the abstract syntax.For model transformation and code generation,the notation has to be represented as models.This paper proposes the notation definition metamodel (NDM) for metamodeling tools by summarizing and analyzing the notation of UML and UML family.For the three problems on notation definition,NDM is composed of three parts:basic figures and layouts,location relations and abstract syntax bridges.The notation model defined by NDM can be transformed to usable source codes.This paper also makes a comparison between NDM and other methods,and the results show that NDM have some advantages over other methods.NDM has been implemented in PKU MetaModeler,and some practices of NDM are introduced.