我试图通过一个练习来理解 Javascript 中的组合和“排序”概念:
定义。“作品”
compose(f,g)(x) = f(g(x))
定义。
sequence(f,g)(x) = g(f(x))
更多参数的“排序”sequence(f,g)(...args) = g(f(...args))
const sequence2 = (f1, f2) => (...args) => f2( f1(...args) );
const sequence = (f1, ...fRest) => fRest.reduce(sequence2, f1);
const f1 = (a, b) => {
console.log(`[f1] working on: ${a} and ${b}`);
return a + b;
}
const f2 = a => `Result is ${a}`;
const sequenceResult = sequence(f1, f1, f2)(1, 2, 5);
console.log(sequenceResult);
控制台显示:
[f1] working on: 1 and 2
[f1] working on: 3 and undefined
Result is NaN
似乎序列中的第二个函数无法访问 args:我遗漏了一些东西,或者它是处理参数的错误方法?(序列函数适用于没有参数的函数)。
这里是JSFiddle