marrionluaka

const applyDiscount = (price, discount) =>
  moneyToFloat(price) // => Box(3.99)
    .fold(cost => 
           percentToFloat(discount) // => Box(0.15)
              .fold(savings => cost - cost * savings)); // 3.99 - (3.99 * 0.15)

marrionluaka

var Node = (function(){
	return function _Node(operation, value, leftChild, rightChild){
		this.operation = operation;
		this.value = value;
		this.leftChild = leftChild;
		this.rightChild = rightChild;
	};
}());

function evaluate(node){