Add Navigable interface

src/parser/Parser.ts

@@ -3,6 +3,7 @@ import { Variables } from "../runtime/Variables";
 import { FadeInfo } from "../view/model/FadeInfo";
 import { Menu } from "../view/model/Menu";
 import { ViewModel } from "../view/model/ViewModel";
+import { Navigable } from "../view/model/Navigable";
 import { Token } from "./Token";
 import { TokenType } from "./TokenType";
 import {
@@ -13,7 +14,7 @@ import {
     Operator
 } from "./ast";
 
-export class Parser {
+export class Parser implements Navigable {
     private readonly EOF = new Token("", TokenType.EOF);
 
     private tokensCount: number
@@ -43,17 +44,21 @@ export class Parser {
         this.vm = view
     }
 
-    public setPosition(position): void {
+    public setPosition(position: number): void {
         this.position = position;
         this.next();
     }
 
-    public jumpLabel(label): void {
+    public jumpLabel(label: string): void {
         if (label in this.labels) {
             this.position = this.labels[label];
         }
     }
 
+    public getLastPosition(): number {
+        return this.lastPosition;
+    }
+
     public next(): void {
         this.lastPosition = this.position;
 

src/view/model/Navigable.ts

@@ -0,0 +1,10 @@
+export interface Navigable {
+
+    setPosition(position: number): void
+    getLastPosition(): number
+    
+    next(): void
+    jumpLabel(label: string): void
+    prevScene(): void
+    nextScene(): void
+}