Add Disposable and DisposableList

src/lang/Disposable.ts

@@ -0,0 +1,24 @@
+import IDisposable from "./IDisposable";
+
+export default class Disposable implements IDisposable {
+  private readonly _cleanup: () => void;
+  private _isDisposed: boolean;
+
+  constructor(cleanup: () => void) {
+    this._cleanup = cleanup;
+    this._isDisposed = false;
+  }
+
+  get isDisposed() {
+    return this._isDisposed;
+  }
+
+  public dispose(): void {
+    if (this._isDisposed) {
+      return;
+    }
+
+    this._cleanup();
+    this._isDisposed = true;
+  }
+}