  Dataflow networks have application in various forms of stream processing, for
example for parallel processing of multimedia data. The description of dataflow
graphs, including their firing behavior, is typically non-compositional and not
amenable to separate compilation. This article considers a dataflow language
with a type and effect system that captures the firing behavior of actors. This
system allows definitions to abstract over actor firing rates, supporting the
definition and safe composition of actor definitions where firing rates are not
instantiated until a dataflow graph is launched.
