Create 2636-promise-pool.js

Author: everthis

2636-promise-pool.js

@@ -0,0 +1,29 @@
+/**
+ * @param {Function[]} functions
+ * @param {number} n
+ * @return {Function}
+ */
+const promisePool = async function(functions, n) {
+  const it = functions[Symbol.iterator]()
+  
+  const add = async () => {
+    const { value, done } = it.next()
+    if(value) {
+      await value()
+      await add()
+    }
+  }
+  
+  const arr = []
+  for(let i = 0; i < n; i++) {
+    arr.push(add())
+  }
+  
+  return Promise.all(arr)
+};
+
+/**
+ * const sleep = (t) => new Promise(res => setTimeout(res, t));
+ * promisePool([() => sleep(500), () => sleep(400)], 1)
+ *   .then(console.log) // After 900ms
+ */