A Graphical Multistage Calculus
Ellner, Stephan; Taha, Walid
DateJuly 22, 2005
While visual programming languages continue to gain popularity in domains ranging from scientific computing to real-time systems, the wealth of abstraction mechanisms, reasoning principles, and type systems developed over the last thirty years is currently available mainly for textual languages. With the goal of understanding how results in the textual languages can be mapped to the graphical setting, we develop the visual calculus PreVIEW. While this calculus visualizes computations in dataflow-style similar to languages like LabVIEW and Simulink, its formal model is based on Ariola and Blom's work on cyclic lambda calculi. We extend this model with staging constructs, establish a precise connection between textual and graphical program representations, and show how a reduction semantics for a multi-stage language can be lifted from the textual to the graphical setting.