JS 柯里化函數隨筆

模擬實現

const slice = Array.prototype.slice;
const curryMaker = function(fn, len) {
  const curriedArgs = slice.call(arguments, 2);
  return curry.apply(this, [fn, (len || fn.length), ...curriedArgs]);
};

const curry = function(fn, len) {
  const curriedArgs = slice.call(arguments, 2);
  return function() {
    const args = [...curriedArgs, ...arguments];
    // 如果與預期的參數長度一致，則執行函數，獲取返回值
    if (args.length >= len) {
      return fn.apply(this, args);
    }
    // 否則，整理入參，返回curry函數的結果
    return curry.apply(this, [fn, len, ...args]);
  };
};

function calcSum() {
  return [...arguments].reduce((pre, value) => { return pre + value }, 0);
}
const calcSumCurry = curry(calcSum, 4);

const nextCalc = calcSumCurry(1, 2);
console.log(nextCalc(3)(4));