最近看阮大神的es6入門中提到了一個部署管道機制(pipeline)的例子,它的做用就是:前一個函數的輸出是後一個函數的輸入。javascript
const pipeline = (...funcs) => val => funcs.reduce((a, b) => b(a), val); const plus1 = a => a + 1; const mult2 = a => a * 2; const addThenMult = pipeline(plus1, mult2); console.log(addThenMult(5)) // 12
上面這種寫法,理解有點困難,而後根據本身的大體理解,翻譯了一下這個函數:java
const pipeline = function(...funcs){ return function(val){ return funcs.reduce(function(a,b){ return b(a); },val); } } const plus1 = function(a){ return a+1; } const mult2 = function(a){ return a*2; } const addThenMult = function(num){ return pipeline(plus1(num),mult2); } console.log(addThenMult(5)); //12
上面的寫法等同於下面的寫法:es6
const plus1 = a => a + 1; const mult2 = a => a * 2; mult2(plus1(5)) // 12