Hyperflow: a visual programming language for pen computers

The design philosophy of the Hyperflow visual programming language and an overview of its semantic model are presented. The concept of visually interactive process, vip, is introduced as the fundamental element of the semantics. Vips communicate with each other through exchange of signals, either discrete or continuous. Each vip communicates with the user through its own interface box by displaying on the box information about the vip and by receiving information pen-scribed on the box. There are four different communication modes: mailing, posting, channeling, and broadcasting. Mailing and posting are for discrete signals and channeling and broadcasting are for continuous signals. Simple Hyperflow programs are given including a specification for the Line-Clock device driver