js currying

柯里化

概念

柯里化(currying)又称部分求值,is a technique for converting a multi-parameter function to a one-parameter function.

Currying is the way to go f(a, b, c) The functional form of is changed to f(a)(b)的形式.柯里化不会调用函数,Just transform the function.

原理

A curried function of a function,is to pass in a function as a parameter“柯里化函数”,The function receives the incoming function parameters inside the function,After receiving the function does not evaluate,而是继续返回另一个函数,Save the parameters just passed in as a closure,After all parameters have been received,trigger evaluation.

效果

/** * 柯里化函数 * @param {function} f 需要柯里化的函数 * */
function curry(f) {
    
	return fucntion(a) {
    
		return function(b) {
    
			return function(c) {
    
				f(a, b, c);
			}
		}
	}
};

function sum(a, b, c) {
    
	return a + b + c;
}

let currySum = curry(sum);
console.log(currySum(1, 2, 3));

高级柯里化

function curry(f) {
    
	return function curried(...args) {
    
		if(args.length >= f.length) {
    
			return f.apply(this, args);
		}else {
    
			return function(...args1) {
    
				return curried.apply(this, args.concat(args2));
			} 
		}
	}
}

// 使用方式
function sum(a, b, c) {
    
	return a + b + c;
}

let currySum = curry(sum);
console.log(currySum(1, 2, 3));
console.log(currySum(1, 2)(3));
console.log(currySum(1)(2)(3));