Lucid (programming language)

It was designed by Bill Wadge and Ed Ashcroft and described in the 1985 book Lucid, the Dataflow Programming Language.

Each statement can be understood as an equation defining a network of processors and communication lines between them through which data flows.

Iteration is simulated by 'current' values and 'fby' (read as 'followed by') operator allowing composition of streams.

Lucid was originally conceived as a disciplined, mathematically pure, single-assignment language, in which verification would be simplified.

An important consequence of this is that explicit logic for updating related values is avoided, which results in substantial code reduction, compared to mainstream languages.