Multiparam Memoization: createApplier

multimemo.createApplier.js

function createApplier(calculator, memoizers, totalValueCount, currValues) {
  const memoize = memoizers[currValues.length];

  function applyNonFinalValue(value) {
    const nextValues = [...currValues, value];
    return createApplier(calculator, memoizers, totalValueCount, nextValues);
  }

  function applyFinalValue(value) {
    return calculator(...currValues, value);
  }

  const applyValue = (
    // If the next one applies the final value, that is it would bring values.length
    // up to totalValueCount, use applyFinalValue.  Otherwise, use
    // applyNonFinalValue.
    currValues.length >= totalValueCount - 1 ? applyFinalValue : applyNonFinalValue
  );

  return memoize(applyValue);
}