Tabular 表达式是一种采用表格化结构组织函数或关系的形式化描述工具,在需求工程领域中具有广泛的应用,为Tabular表达式建立形式的语义模型是非常必要的。针对Tabular表达式通用模型,给出了Tabular表达式的形式文法及指称语义。通过定义形式文法中各语法单元的语义指派方程,描述了 Tabular 表达式的指称语义,分别对传统类型 Tabular 表达式和新类型 Tabular 表达式中一些典型表类型的指称语义进行了描述,并与其他几种Tabular表达式的语义描述方法进行了比较。分析结果表明:该语义描述方法不仅准确描述了Tabular表达式的语义,而且不再受Tabular表达式模型和Tabular表达式类型的限制,打破了现有方法的局限性,是一种非常有效的方法。
Tabular expressions are a formal notation using Tabular form to organize functions or relationships, and they have been widely used in documenting and analyzing software systems. To avoid misunderstanding and to support user with trustworthy tools, the meaning of these expressions must be fully defined. This paper presents the formal grammar and denotational semantics of the Tabular expressions in general model. By defining semantics assigned equation of each syntax unit of the Tabular expressions’ formal grammar, denotational semantics of the Tabular expressions is specified. In addition, the meaning of some classical Tabular expression types and new table types are described based on this semantics. Comparisons made with other semantics description methods show that the denotational semantics method defines Tabular expressions’ meaning precisely without subjecting to the restrictions of models and types of Tabular expressions. The proposed method breaks the existing methods’ limitations and is an effective method.