FP Is Not Data Flow

May 25, 2025

FP is not data flow.

Data flow transfers data.
FP transfers data and control flow.
Data flow transfers data and places it in a queue for the receiver, while FP transfers data and places it on a stack for the receiver, requiring the receiver to act upon the top of the stack immediately.
Data flow transfers data and expects the receiver to act upon it at their convenience.
Data flow transfers data to a receiver without requiring a routing strategy.
FP requires a routing strategy. The called function must return a value to the caller.
Data flow is represented by nodes, wires, and ports. Nodes own ports, and wires only flow between ports.
A ‘nodes and ports and wires’ strategy allows multiple ports per node.
FP requires that a node have exactly one input port and one output port (the appearance of multiple function parameters and return values is merely a technique of destructuring).

Twitter: @paul_tarvydas

Paul’s Substack