ShapeRank is a statically typed, functional programming lan- guage designed for machine learning, data analytics and re- active programming. All ShapeRank values are multidimen- sional streams, known as hyperstreams, and all operations are automatically lifted to process hyperstreams in parallel. This lifting originates in the APL language family, and is known as rank polymorphism. ShapeRank extends rank polymorphism to hyperstreams. ShapeRank functions may be either synchronous or reactive. We introduce ShapeRank with a focus on its reactive behavior.

**This is an in-progress paper **