feat(d.ts)

types/iterators/Bidirectional.d.ts

@@ -0,0 +1,9 @@
+import { ForwardIterator } from "./Forward";
+
+export class BidirectionalIterator<T> extends ForwardIterator<T> {
+  /**
+    * decrements iterator, it doesn't make copy
+    * @returns {this}
+    */
+  dec(): this;
+} 

types/iterators/Forward.d.ts

@@ -0,0 +1,24 @@
+export class Item<T> {
+  value: T
+}
+
+export class ForwardIterator<T> {
+  clone(): ForwardIterator<T>;
+  copy(rhs: ForwardIterator<T>): this;
+  deref(): Item<T>;
+  eq(rhs: ForwardIterator<T>): boolean;
+  /**
+    * increments iterator, it doesn't make copy
+    * @returns {this}
+    */
+  inc(): this;
+  
+  /**
+    * move-semantics, here it just copies rhs into this
+    * @returns {this}
+    */
+  move(rhs: ForwardIterator<T>): this;
+  get value(): T;
+  set value(value: T);
+  neq(rhs: ForwardIterator<T>): boolean;
+}