Recently I became aware of “FAC: A Functional APL Language” a 1986 paper by Hai-Chen Tu and Alan Perlis[1]. Unlike traditional APLs it allows you to define your

Recently I became aware of “FAC: A Functional APL Language” a 1986 paper by Hai-Chen Tu and Alan Perlis[1]. Unlike traditional APLs it allows you to define your own “operators” (second order functions), such as “x (F SWAP) y: y F x”, where x and y can be congruent arrays. It even allows infinite arrays, which can be evaluated lazily and provides a powerful operator on them (let’s call it “$”) such that “1 (+ $) 1” is the Fibonacci sequence! Since FAC functions are pure, in principle you can evaluate things in parallel. It occurs to me that operators can be considered connectors! [1] https://ieeexplore.ieee.org/document/1695470 https://ieeexplore.ieee.org/document/1695470