vCGG:一种基于虚结点的空间图文法形式框架

作为一种二维的形式化方法，图文法为可视化语言提供了直观而规范的描述手段.然而，大多数图文法形式框架在空间语义处理能力方面有所不足，影响了图文法的表达能力及其实际应用范围.针对现存的问题，构建了一种新型空间图文法形式框架vCGG （virtual-node based coordinate graph grammar）.区别于其他空间图文法，vCGG在产生式中通过定义虚结点的概念描述产生式与主图之间的语法结构与空间语义关系，在保留抽象能力的同时，提高了其空间语义配置性能.通过与几种典型空间图文法框架比较，vCGG形式框架在直观性、规范性、表达能力以及分析效率方面均有着较好的表现.

vCGG: Virtual-node Based Spatial Graph Grammar Formalism

As a two-dimensional formal method, Graph grammar provides an intuitive and formal way to specify visual programming languages. However, most existing graph grammar formalisms have some deficiencies in the ability of dealing with spatial semantics, which influences the expressive power and practical application scope of graph grammar. For solving the problems, this study defines visual node to build a new spatial graph grammar formalism vCGG (virtual-node based coordinate graph grammar). Different from other spatial graph grammars, vCGG takes the virtual nodes to specify the relationships of syntax structure and spatial semantic between host graphs and productions, which reserves the power of the abstraction and improves the specification of spatial semantics. Compared with other spatial graph grammars, the formalism of vCGG has good performance in the intuitiveness, normalization, expressive power, and analysis efficiency.