We introduce a meta-model based on formal languages, dubbed formal choreographic languages, to study message-passing systems. Our framework allows us to generalise standard constructions from the literature and to compare them. In particular, we consider notions such as global view, local view, and projections from the former to the latter. The correctness of local views projected from global views is characterised in terms of a closure property. We consider a number of communication properties -- such as (dead)lock-freedom -- and give conditions on formal choreographic languages to guarantee them. Finally, we show how formal choreographic languages can capture existing formalisms; specifically we consider communicating finite-state machines, choreography automata, and multiparty session types. Notably, formal choreographic languages, differently from most approaches in the literature, can naturally model systems exhibiting non-regular behaviour.

翻译：我们引入一种基于形式语言的元模型，称为形式化编排语言，用于研究消息传递系统。该框架使我们能够推广文献中的标准构造并对其进行比较。具体而言，我们考虑了全局视图、局部视图以及从前者到后者的投影等概念。全局视图投影得到的局部视图的正确性可通过封闭性属性进行刻画。我们研究了若干通信属性（如无（死）锁性质），并给出了形式化编排语言保证这些属性的条件。最后，我们展示了形式化编排语言如何捕捉现有形式化体系：具体包括通信有限状态机、编排自动机以及多方会话类型。值得注意的是，与文献中大多数方法不同，形式化编排语言能够自然地建模呈现非正则行为的系统。