are_composable: Check if two functions are composable
In arendsee/pied: functions for compositional, bifurcating pipelines

Description Usage Arguments Value

Inputs are considered to be composable if they are functions and are either untyped or have composable types. Typed functions (f,g) are composable if 1) f's output is not NA (i.e. is not a sink), 2) g's input is not NA (i.e. is not a source), and 3) f's output equals g's input.