Add optimized examples

tshemsedinov · tshemsedinov · commit 8cc35daa4480 · 2018-11-18T02:07:39.000+02:00
diff --git a/JavaScript/5-each-opt.js b/JavaScript/5-each-opt.js
@@ -0,0 +1,45 @@
+'use strict';
+
+const INTERVAL = 10;
+
+const numbers = new Array(1000).fill(1);
+
+const each = (array, fn) => {
+  let time = Date.now();
+  let i = 0;
+  const last = array.length - 1;
+
+  const next = () => {
+    while (i <= last) {
+      const now = Date.now();
+      const diff = now - time;
+      if (diff > INTERVAL) {
+        time = now;
+        setTimeout(next, 0);
+        break;
+      } else {
+        fn(array[i], i++);
+      }
+    }
+  };
+
+  next();
+};
+
+let k = 0;
+
+const timer = setInterval(() => {
+  console.log('next ', k++);
+}, 10);
+
+const begin = process.hrtime.bigint();
+
+each(numbers, (item, i) => {
+  console.log(i);
+  if (i === 999) {
+    clearInterval(timer);
+    const diff = (process.hrtime.bigint() - begin) / 1000000n;
+    console.log('Time(ms):', diff.toString());
+    console.dir({ k });
+  }
+});
diff --git a/JavaScript/6-for-opt.js b/JavaScript/6-for-opt.js
@@ -0,0 +1,59 @@
+'use strict';
+
+const INTERVAL = 10;
+
+const range = {
+  start: 1,
+  end: 1000,
+  [Symbol.asyncIterator]() {
+    let time = Date.now();
+    let value = this.start;
+    return {
+      next: () => {
+        const now = Date.now();
+        const diff = now - time;
+        if (diff > INTERVAL) {
+          time = now;
+          return new Promise((resolve, reject) => {
+            setTimeout(() => {
+              resolve({
+                value,
+                done: value++ === this.end + 1
+              });
+            }, 0);
+          });
+        } else {
+          return Promise.resolve({
+            value,
+            done: value++ === this.end + 1
+          });
+        }
+      }
+    };
+  }
+};
+
+console.dir({
+  range,
+  names: Object.getOwnPropertyNames(range),
+  symbols: Object.getOwnPropertySymbols(range),
+});
+
+let k = 0;
+
+const timer = setInterval(() => {
+  console.log('next ', k++);
+}, 10);
+
+(async () => {
+  const begin = process.hrtime.bigint();
+  for await (const number of range) {
+    console.log(number);
+    if (number === range.end) {
+      clearInterval(timer);
+    }
+  }
+  const diff = (process.hrtime.bigint() - begin) / 1000000n;
+  console.log('Time(ms):', diff.toString());
+  console.dir({ k });
+})();
