diff --git a/packages/misc/default-number-value/README.md b/packages/misc/default-number-value/README.md
new file mode 100644
index 00000000..4124caf2
--- /dev/null
+++ b/packages/misc/default-number-value/README.md
@@ -0,0 +1,19 @@
+# @x-oasis/default-number-value
+
+## Installation
+
+```bash
+$ npm i @x-oasis/default-number-value
+```
+
+## How to use
+
+```typescript
+import booleanWithDefault from '@x-oasis/default-number-value'
+```
+
+## How to run test
+
+```bash
+$ pnpm test
+```
\ No newline at end of file
diff --git a/packages/misc/default-number-value/package.json b/packages/misc/default-number-value/package.json
new file mode 100644
index 00000000..69b88521
--- /dev/null
+++ b/packages/misc/default-number-value/package.json
@@ -0,0 +1,27 @@
+{
+  "name": "@x-oasis/default-number-value",
+  "version": "0.1.8",
+  "description": "default-number-value function",
+  "main": "dist/index.js",
+  "typings": "dist/index.d.ts",
+  "module": "dist/default-number-value.esm.js",
+  "files": [
+    "dist",
+    "index.ts",
+    "src"
+  ],
+  "scripts": {
+    "build": "tsdx build --tsconfig tsconfig.build.json",
+    "clean": "rimraf ./dist",
+    "test": "vitest",
+    "compile": "tsc -p tsconfig.build.json"
+  },
+  "author": "",
+  "license": "ISC",
+  "devDependencies": {
+    "tsdx": "^0.14.1"
+  },
+  "dependencies": {
+    "@x-oasis/default-value": "workspace:*"
+  }
+}
diff --git a/packages/misc/default-number-value/src/index.ts b/packages/misc/default-number-value/src/index.ts
new file mode 100644
index 00000000..c119075a
--- /dev/null
+++ b/packages/misc/default-number-value/src/index.ts
@@ -0,0 +1,10 @@
+import defaultValue from '@x-oasis/default-value';
+
+function defaultNumberValue(value, _defaultValue) {
+  const _value = defaultValue(value, _defaultValue);
+  const _n = Number(_value);
+  if (typeof _n !== 'number') return 0;
+  return _n;
+}
+
+export default defaultNumberValue;
diff --git a/packages/misc/default-number-value/test/test.spec.ts b/packages/misc/default-number-value/test/test.spec.ts
new file mode 100644
index 00000000..e2e270a0
--- /dev/null
+++ b/packages/misc/default-number-value/test/test.spec.ts
@@ -0,0 +1,10 @@
+import { expect, test } from 'vitest';
+import defaultNumberValue from '../src';
+
+test('boolean with default', async () => {
+  expect(defaultNumberValue(undefined, 1)).toBe(1);
+  expect(defaultNumberValue(NaN, 1)).toBe(1);
+  expect(defaultNumberValue(null, 1)).toBe(1);
+  expect(defaultNumberValue(3, 4)).toBe(3);
+  expect(defaultNumberValue(0, 4)).toBe(0);
+});
diff --git a/packages/misc/default-number-value/tsconfig.build.json b/packages/misc/default-number-value/tsconfig.build.json
new file mode 100644
index 00000000..c8613f05
--- /dev/null
+++ b/packages/misc/default-number-value/tsconfig.build.json
@@ -0,0 +1,12 @@
+{
+  "extends": "../../../tsconfig.build.json",
+  "compilerOptions": {
+    "outDir": "./dist",
+    "esModuleInterop": true
+  },
+
+  "include": [
+    "index.ts",
+    "src/**/*"
+  ]
+}
\ No newline at end of file
diff --git a/packages/misc/default-number-value/tsconfig.json b/packages/misc/default-number-value/tsconfig.json
new file mode 100644
index 00000000..a5aa7cc0
--- /dev/null
+++ b/packages/misc/default-number-value/tsconfig.json
@@ -0,0 +1,7 @@
+{
+  "extends": "../../../tsconfig.json",
+  "compilerOptions": {
+    "jsx": "react",
+    "esModuleInterop": true
+  }
+}
\ No newline at end of file
diff --git a/packages/misc/default-number-value/vitest.config.ts b/packages/misc/default-number-value/vitest.config.ts
new file mode 100644
index 00000000..31d7ded7
--- /dev/null
+++ b/packages/misc/default-number-value/vitest.config.ts
@@ -0,0 +1,26 @@
+// import path from 'path';
+// import tsPath from 'vite-tsconfig-paths';
+import { defineConfig } from 'vitest/config';
+
+// const __dirname = import.meta.url.slice(7, import.meta.url.lastIndexOf('/'));
+
+export default defineConfig({
+  test: {
+    globals: true,
+    include: ['test/**/*.(spec|test).ts'],
+    exclude: ['node_modules/**'],
+    threads: false,
+
+    coverage: {
+      provider: 'istanbul', // or 'c8'
+    },
+  },
+
+  // plugins: [tsPath()],
+  resolve: {
+    alias: {},
+  },
+  define: {
+    __DEV__: false,
+  },
+});
diff --git a/packages/schedule/debounce/README.md b/packages/schedule/debounce/README.md
new file mode 100644
index 00000000..57d2962a
--- /dev/null
+++ b/packages/schedule/debounce/README.md
@@ -0,0 +1,33 @@
+# @x-oasis/debounce
+
+## Installation
+
+```bash
+$ npm i @x-oasis/debounce
+```
+
+## How to use
+
+```typescript
+import debounce from '@x-oasis/debounce'
+```
+
+## How to run test
+
+```bash
+$ pnpm test
+```
+
+- resize: only care the final value
+- keypress on autocomplete form with Ajax request
+
+The main difference between this and debouncing is that debounce guarantees the execution of the function regularly, at least every X milliseconds.
+
+
+
+## Further Reading
+
+- [lodash - debounce](https://lodash.com/docs/4.17.15#debounce)
+- [Debouncing and Throttling Explained Through Examples](https://css-tricks.com/debouncing-throttling-explained-examples/)
+- [Debouncing Javascript Methods](http://unscriptable.com/2009/03/20/debouncing-javascript-methods/)
+- [Difference Between throttling and debouncing a function](https://stackoverflow.com/questions/25991367/difference-between-throttling-and-debouncing-a-function)
\ No newline at end of file
diff --git a/packages/schedule/debounce/package.json b/packages/schedule/debounce/package.json
new file mode 100644
index 00000000..d21d00e5
--- /dev/null
+++ b/packages/schedule/debounce/package.json
@@ -0,0 +1,23 @@
+{
+  "name": "@x-oasis/debounce",
+  "version": "0.1.8",
+  "description": "debounce function",
+  "main": "dist/index.js",
+  "typings": "dist/index.d.ts",
+  "module": "dist/debounce.esm.js",
+  "scripts": {
+    "build": "tsdx build --tsconfig tsconfig.build.json",
+    "clean": "rimraf ./dist",
+    "test": "vitest",
+    "compile": "tsc -p tsconfig.build.json"
+  },
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "@x-oasis/default-boolean-value": "workspace:*",
+    "@x-oasis/default-number-value": "workspace:*"
+  },
+  "devDependencies": {
+    "tsdx": "^0.14.1"
+  }
+}
diff --git a/packages/schedule/debounce/src/index.ts b/packages/schedule/debounce/src/index.ts
new file mode 100644
index 00000000..9cc2457d
--- /dev/null
+++ b/packages/schedule/debounce/src/index.ts
@@ -0,0 +1,67 @@
+import { Options } from './types';
+import defaultBooleanValue from '@x-oasis/default-boolean-value';
+import defaultNumberValue from '@x-oasis/default-number-value';
+
+const DEFAULT_TIMEOUT = 200;
+
+/**
+ *
+ * @param func
+ * @param timeout
+ * @returns
+ *
+ * trigger first, then trigger on the last
+ */
+
+export default function debounce(
+  func: Function,
+  timeout = DEFAULT_TIMEOUT,
+  options: Options
+) {
+  let lastPerformTime = 0;
+  let lastCallTime = 0;
+  const leading = defaultBooleanValue(options?.leading, false);
+  const trailing = defaultBooleanValue(options?.trailing, true);
+  const maxTime = defaultNumberValue(options?.maxTime, 0);
+  const resetTime = defaultNumberValue(options?.resetTime, 0);
+  let timeoutId = undefined;
+  let lastArgs = undefined;
+  let result = undefined;
+  let lastThis = undefined;
+
+  function clock() {}
+
+  function shouldPerform(time) {
+    if (!lastPerformTime) return true;
+    if (Date.now() - time > timeout) return true;
+    return false;
+  }
+
+  function perform() {
+    result = func.apply(lastThis, lastArgs);
+    lastPerformTime = Date.now();
+    timeoutId = undefined;
+    lastArgs = undefined;
+  }
+
+  function maxTimeoutHandler() {}
+
+  function performLeading() {
+    if (leading) perform();
+  }
+
+  function performTrailing() {}
+
+  return function (...args) {
+    const now = Date.now();
+    lastCallTime = now;
+    lastArgs = args;
+    lastThis = this; // eslint-disable-line
+
+    if (shouldPerform(now)) {
+      if (!timeoutId) {
+        performLeading();
+      }
+    }
+  };
+}
diff --git a/packages/schedule/debounce/src/types.ts b/packages/schedule/debounce/src/types.ts
new file mode 100644
index 00000000..3a8c5170
--- /dev/null
+++ b/packages/schedule/debounce/src/types.ts
@@ -0,0 +1,9 @@
+type ResolveArgs = (...args: [any]) => any;
+
+export type Options = {
+  leading: boolean;
+  trailing: boolean;
+  maxTime: number;
+  resetTime: number;
+  resolveArgs: ResolveArgs;
+};
diff --git a/packages/schedule/debounce/test/test.spec.ts b/packages/schedule/debounce/test/test.spec.ts
new file mode 100644
index 00000000..88f35611
--- /dev/null
+++ b/packages/schedule/debounce/test/test.spec.ts
@@ -0,0 +1,5 @@
+import { expect, test } from 'vitest';
+
+test('vitest', async () => {
+  expect('vitest').toBe('vitest');
+});
diff --git a/packages/schedule/debounce/tsconfig.build.json b/packages/schedule/debounce/tsconfig.build.json
new file mode 100644
index 00000000..17632b25
--- /dev/null
+++ b/packages/schedule/debounce/tsconfig.build.json
@@ -0,0 +1,11 @@
+{
+  "extends": "../../../tsconfig.build.json",
+  "compilerOptions": {
+    "outDir": "./dist",
+    "esModuleInterop": true
+  },
+
+  "include": [
+    "src/**/*"
+  ]
+}
\ No newline at end of file
diff --git a/packages/schedule/debounce/tsconfig.json b/packages/schedule/debounce/tsconfig.json
new file mode 100644
index 00000000..a5aa7cc0
--- /dev/null
+++ b/packages/schedule/debounce/tsconfig.json
@@ -0,0 +1,7 @@
+{
+  "extends": "../../../tsconfig.json",
+  "compilerOptions": {
+    "jsx": "react",
+    "esModuleInterop": true
+  }
+}
\ No newline at end of file
diff --git a/packages/schedule/debounce/vitest.config.ts b/packages/schedule/debounce/vitest.config.ts
new file mode 100644
index 00000000..31d7ded7
--- /dev/null
+++ b/packages/schedule/debounce/vitest.config.ts
@@ -0,0 +1,26 @@
+// import path from 'path';
+// import tsPath from 'vite-tsconfig-paths';
+import { defineConfig } from 'vitest/config';
+
+// const __dirname = import.meta.url.slice(7, import.meta.url.lastIndexOf('/'));
+
+export default defineConfig({
+  test: {
+    globals: true,
+    include: ['test/**/*.(spec|test).ts'],
+    exclude: ['node_modules/**'],
+    threads: false,
+
+    coverage: {
+      provider: 'istanbul', // or 'c8'
+    },
+  },
+
+  // plugins: [tsPath()],
+  resolve: {
+    alias: {},
+  },
+  define: {
+    __DEV__: false,
+  },
+});
diff --git a/packages/schedule/throttle/src/index.ts b/packages/schedule/throttle/src/index.ts
index c7c62780..37ae5f45 100644
--- a/packages/schedule/throttle/src/index.ts
+++ b/packages/schedule/throttle/src/index.ts
@@ -17,45 +17,24 @@ export default function throttle(
     | boolean
 ) {
   let last = 0;
-  let timeoutHandler = null;
-  const fallback = !!fallbackOptions;
-
-  let queue = [];
+  let _args = [];
 
   return function throttled(...args: any[]) {
     const now = Date.now();
 
-    if (now - last > threshold) {
-      last = now;
-      if (timeoutHandler) {
-        clearTimeout(timeoutHandler);
-        timeoutHandler = null;
-        queue = [];
-      }
-
-      fn.apply(null, args);
-      return;
-    }
-
-    if (!fallback) return;
-
-    timeoutHandler = setTimeout(() => {
-      const len = queue.length;
-      if (len) {
-        const currentArgs = queue[len - 1];
-        queue = [];
-        fn.apply(null, currentArgs);
-      }
-    }, threshold);
-
-    let nextArgs = args;
     const persistArgs =
       typeof fallbackOptions === 'object' ? fallbackOptions.persistArgs : null;
 
+    _args = args;
+
     if (typeof persistArgs === 'function') {
-      nextArgs = persistArgs(args);
+      _args = persistArgs(args);
     }
 
-    queue.push(nextArgs);
+    if (now - last > threshold) {
+      last = now;
+
+      return fn.apply(this, args);
+    }
   };
 }
diff --git a/packages/struct/heap/src/index.ts b/packages/struct/heap/src/index.ts
index fc543ed2..7cc82c08 100644
--- a/packages/struct/heap/src/index.ts
+++ b/packages/struct/heap/src/index.ts
@@ -10,7 +10,7 @@ class Heap<T extends HeapBasicItem = HeapBasicItem> {
   private _size: number;
   private _comparator: Comparator;
 
-  constructor(items: Array<T>, comparator: Comparator) {
+  constructor(items: Array<T>, comparator?: Comparator) {
     this._items = items || [];
     this._size = this._items.length;
     this._comparator = comparator || defaultComparator;
diff --git a/packages/struct/heap/test/test.spec.ts b/packages/struct/heap/test/test.spec.ts
index f1a160bf..272e686f 100644
--- a/packages/struct/heap/test/test.spec.ts
+++ b/packages/struct/heap/test/test.spec.ts
@@ -1,85 +1,9 @@
 import { expect, describe, it } from 'vitest';
-
-import PrefixIntervalTree from '../src';
+import Heap from '../src';
 
 describe('basic', () => {
-  it('init with number ', () => {
-    const intervalTree = new PrefixIntervalTree(4);
-    expect(intervalTree.getHeap()).toEqual([0, 0, 0, 0, 0, 0, 0, 0]);
-  });
-
-  it('init with arr ', () => {
-    const intervalTree = new PrefixIntervalTree([0, 2, 3, 1]);
-    expect(intervalTree.getHeap()).toEqual([0, 6, 2, 4, 0, 2, 3, 1]);
-  });
-
-  it('this.heap[1] should be the total value', () => {
-    const intervalTree = new PrefixIntervalTree([0, 2, 3, 1]);
-    expect(intervalTree.getHeap()[1]).toEqual(6);
-  });
-
-  it('heap size should be the power of 2', () => {
-    const intervalTree = new PrefixIntervalTree(10);
-    expect(intervalTree.getSize()).toBe(16);
-  });
-});
-
-describe('leastStrictUpperBound', () => {
-  it('set index value', () => {
-    const intervalTree = new PrefixIntervalTree(4);
-    intervalTree.set(0, 100);
-    intervalTree.set(1, 100);
-    intervalTree.set(2, 100);
-    intervalTree.set(3, 100);
-    intervalTree.set(4, 100);
-    intervalTree.set(5, 100);
-    intervalTree.set(6, 100);
-    intervalTree.set(7, 100);
-    intervalTree.set(8, 100);
-    intervalTree.set(9, 100);
-    expect(intervalTree.getHeap()).toEqual([
-      0, 1000, 800, 200, 400, 400, 200, 0, 200, 200, 200, 200, 200, 0, 0, 0,
-      100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 0, 0, 0, 0, 0, 0,
-    ]);
-    expect(intervalTree.leastStrictUpperBound(330)).toBe(3);
-    expect(intervalTree.leastStrictUpperBound(400)).toBe(3);
-    expect(intervalTree.leastStrictUpperBound(401)).toBe(4);
-    expect(intervalTree.leastStrictUpperBound(901)).toBe(9);
-    expect(intervalTree.leastStrictUpperBound(1001)).toBe(9);
-    expect(intervalTree.leastStrictUpperBound(1100)).toBe(9);
-  });
-
-  it('computeRange', () => {
-    const intervalTree = new PrefixIntervalTree(4);
-    intervalTree.set(0, 100);
-    intervalTree.set(1, 100);
-    intervalTree.set(2, 100);
-    intervalTree.set(3, 100);
-    intervalTree.set(4, 100);
-    intervalTree.set(5, 100);
-    intervalTree.set(6, 100);
-    intervalTree.set(7, 100);
-    intervalTree.set(8, 100);
-    intervalTree.set(9, 100);
-    expect(intervalTree.getHeap()).toEqual([
-      0, 1000, 800, 200, 400, 400, 200, 0, 200, 200, 200, 200, 200, 0, 0, 0,
-      100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 0, 0, 0, 0, 0, 0,
-    ]);
-    expect(intervalTree.computeRange(0, 330)).toEqual({
-      startIndex: 0,
-      endIndex: 3,
-    });
-    expect(intervalTree.computeRange(0, 400)).toEqual({
-      startIndex: 0,
-      endIndex: 3,
-    });
-    expect(intervalTree.computeRange(400, 500)).toEqual({
-      startIndex: 3,
-      endIndex: 4,
-    });
-    expect(intervalTree.computeRange(400, 901)).toEqual({
-      startIndex: 3,
-      endIndex: 9,
-    });
+  it('basic', () => {
+    const heap = new Heap([3, 4, 8, 2]);
+    expect(heap.pop()).toEqual(2);
   });
 });
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 67e9979c..ba69f604 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -95,6 +95,15 @@ importers:
     devDependencies:
       tsdx: 0.14.1
 
+  packages/misc/default-number-value:
+    specifiers:
+      '@x-oasis/default-value': workspace:*
+      tsdx: ^0.14.1
+    dependencies:
+      '@x-oasis/default-value': link:../default-value
+    devDependencies:
+      tsdx: 0.14.1
+
   packages/misc/default-value:
     specifiers:
       tsdx: ^0.14.1
@@ -167,6 +176,17 @@ importers:
     devDependencies:
       tsdx: 0.14.1
 
+  packages/schedule/debounce:
+    specifiers:
+      '@x-oasis/default-boolean-value': workspace:*
+      '@x-oasis/default-number-value': workspace:*
+      tsdx: ^0.14.1
+    dependencies:
+      '@x-oasis/default-boolean-value': link:../../misc/default-boolean-value
+      '@x-oasis/default-number-value': link:../../misc/default-number-value
+    devDependencies:
+      tsdx: 0.14.1
+
   packages/schedule/throttle:
     specifiers:
       tsdx: ^0.14.1