on | /mod.ts | rambda@9.2.1

function on

import { on } from "https://deno.land/x/rambda@9.2.1/mod.ts";

on<T, U, R>(

binaryFn: (a: U, b: U) => R,

unaryFn: (value: T) => U,

a: T,

b: T,

): R

It passes the two inputs through unaryFn and then the results are passed as inputs the the binaryFn to receive the final result(binaryFn(unaryFn(FIRST_INPUT), unaryFn(SECOND_INPUT))).

on<T, U, R>(

binaryFn: (a: U, b: U) => R,

unaryFn: (value: T) => U,

a: T,

): (b: T) => R

on<T, U, R>(binaryFn: (a: U, b: U) => R, unaryFn: (value: T) => U): { (a: T, b: T): R; (a: T): (b: T) => R; }

It passes the two inputs through unaryFn and then the results are passed as inputs the the binaryFn to receive the final result(binaryFn(unaryFn(FIRST_INPUT), unaryFn(SECOND_INPUT))).

This method is also known as P combinator.