小猪的博客

发誓我不写Monad教程

我保证,不再在网上又发布一篇Monad教程(By Erik Meijer)

自我娱乐,附赠各种Functional with OO,参见GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
//Define
Monad = function() {
this.value = arguments[0];
};
Monad.prototype.unit = function (value) {
this.value = value;
return this;
}
Monad.prototype.bind = function (func) {
var value = func(this.value);
var monad = new Monad(value);
return monad;
}
Monad.prototype.extract = function () {
return this.value;
}

//Use
var monad = new Monad;
var monad = new Monad(10);

monad.unit(20);
monad.unit(new Monad(30));

monad.bind(function (value) { return value });
var result = monad.bind(function (value) {
return value.extract() * 2;
})

console.log(result.extract());//60

//Test
var monad = new Monad;
monad.unit(10);

console.log(monad.extract());//10

var firstMonad = monad.bind(function (value) {
return value / 2;
});

console.log(firstMonad.extract());//5

var secondMonad = monad.bind(function (value) {
return value + 1;
}).bind(function (value) {
return value + 2;
}).bind(function (value) {
return value + 3;
});

console.log(monad.extract())//10
console.log(secondMonad.extract());//16