Currying函数构造函数

Question

我想知道在javascript中是否有可能做到这一点：

function Hello() { }

Hello.prototype.echo = function echo() {
  return 'Hello ' + this.firstname + '!';
};

// execute the curryed new function
console.log(new Hello()('firstname').echo())

有没有可能做var o = new Class()(param1)(param2)(...)？

提前感谢您的帮助。

Answer 1

将georg的answer与属性数组和用于分配任意数量属性的计数器一起使用。

​

function Hello() {
    var args = ['firstname', 'lastname'],
        counter = 0,
        self = function (val) {
            self[args[counter++]] = val;
            return self;
        };
    Object.setPrototypeOf(self, Hello.prototype);
    return self;
}

Hello.prototype.echo = function echo() {
    return 'Hello ' + this.firstname + ' ' + (this.lastname || '') + '!';
};

console.log(new Hello()('Bob').echo());
console.log(new Hello()('Marie')('Curie').echo());

​

Answer 2

例如：

​

function Hello() {
    let self = function (key, val) {
        self[key] = val;
        return self;
    };
    Object.setPrototypeOf(self, Hello.prototype);
    return self;
}

Hello.prototype.echo = function echo() {
    return 'Hello ' + this.firstname + this.punct;
};

console.log(new Hello()('firstname', 'Bob')('punct', '...').echo())

​

Answer 3

在您的代码中，new Hello('Bob')返回的不是函数，而是一个具有.echo()方法的对象。

当用new实例化时，function Hello(firstname) {}是一个返回对象的构造函数。

// constructor function expecting 1 argument
function Hello(firstname) {
  this.firstname = firstname;
}

// attach a method to the constructor prototype
Hello.prototype.echo = function() {
  return 'Hello ' + this.firstname + '!'; // the method can use the contructor's properties
};

// new Hello('Bob') returns the object, and you can call the .echo() method of that object
console.log(new Hello('Bob').echo())

​