一些简单的东西,被引用和拷贝坑了下。javascript
function *ngrams(sequence, n) { let g = (function *(sequence){yield *sequence})(sequence); let history = []; while (n > 1) { history.push(g.next().value); n--; } for (let item of g) { history.push(item); // look at here. // yield Array.from(history); yield history; history.shift(); } }
若是这时候用Array.from。。。WTF,什么鬼java
> Array.from(ngrams([1,2,3,4,5], 3)); [ [ 4, 5 ], [ 4, 5 ], [ 4, 5 ] ]
若是for of数组
> for (let w of ngrams([1,2,3,4,5], 3)){console.log(w);} [ 1, 2, 3 ] [ 2, 3, 4 ] [ 3, 4, 5 ]
很怀疑Array.from干啥了。。。app
> Array.from(ngrams([1,2,3,4,5], 3), (v)=>{console.log(v)}); [ 1, 2, 3 ] [ 2, 3, 4 ] [ 3, 4, 5 ] > Array.from(ngrams([1,2,3,4,5], 3), (v)=>v); [ [ 4, 5 ], [ 4, 5 ], [ 4, 5 ] ] > Array.from(ngrams([1,2,3,4,5], 3), (v)=>v+1); [ '1,2,31', '2,3,41', '3,4,51' ]
这就明晰了,没想到会在js中碰到这种问题。。。ide
中午见有人讨论求一个数组最小值时这样:this
Math.min.apply(Object.create(null), [1,2,3]);code
说相比高程上说的方法,能更好防止变量污染。ip
因而去翻了翻spidermonkey和v8的实现,发现这个this根本就没用。。。至于apply,咱们如今有v8
Math.min(...[1,2,3]);it
ES6大法好啊。。。