Commands composition user interface pattern

Interactive user interfaces include commands that allow to manipulate data or other objects. While in most cases these commands are atomic, it is possible to support composition of simple command elements into complex commands directly during the user interaction. In this case commands have properties of a language. Prominent example of such interface is the Vim text editor. In this paper properties of this user interfaces design pattern are explored and compared with usual interfaces. The ways to integrate this approach with modern interfaces are also proposed.