4 files changed, 42 insertions, 5 deletions

diff --git a/report/progression.tex b/report/progression.tex
index 6600430..cf4f3d2 100644
--- a/report/progression.tex
+++ b/report/progression.tex
@@ -204,12 +204,27 @@ to perform actions on a particular one (take, drop, use, etc\ldots).
 
 \subsection{back}
 
+The back command was implemented as part of commit f218bf5fa.
+
 \subsection{back test}
 
+The back command works even with any parameter. We will check this later with
+"zuul-with-enums".
+
 \subsection{back back}
 
+When the user enters back twice, he goes two rooms backward. This is working
+correctly.
+
 \subsection{Stack}
 
+The Stack class represents a last-in-first-out (LIFO) stack of objects. The push()
+method allows to add and element at the top of the stack and the pop() method
+allows to retrieve the top item and removes it.
+
+A condition checks whether the Stack is empty before calling the pop() method,
+so that the program does not throw an Exception. This resolve the case when the
+player is at the starting point.
 
 \section{Zuul with tests}
 
diff --git a/src/esieequest/controller/Interpreter.java b/src/esieequest/controller/Interpreter.java
index 5c60c0b..586b329 100644
--- a/src/esieequest/controller/Interpreter.java
+++ b/src/esieequest/controller/Interpreter.java
@@ -63,6 +63,9 @@ class Interpreter {
                         case "go":
                                 this.performer.goTo(command.getOption());
                                 return;
+                        case "back":
+                                this.performer.goBack();
+                                return;
                         case "look":
                                 this.performer.look();
                                 return;
diff --git a/src/esieequest/controller/Performer.java b/src/esieequest/controller/Performer.java
index 6da3901..0ac194f 100644
--- a/src/esieequest/controller/Performer.java
+++ b/src/esieequest/controller/Performer.java
@@ -109,6 +109,14 @@ class Performer {
         }
 
         /**
+         * Changes the current room to the previous one.
+         */
+        public void goBack() {
+                this.game.goToPreviousRoom();
+                this.echo(this.game.getLocationInfo());
+        }
+
+        /**
          * Displays informations about the current place.
          */
         public void look() {
diff --git a/src/esieequest/model/Game.java b/src/esieequest/model/Game.java
index 99afa7c..5f2049c 100644
--- a/src/esieequest/model/Game.java
+++ b/src/esieequest/model/Game.java
@@ -1,6 +1,7 @@
 package esieequest.model;
 
 import java.util.HashMap;
+import java.util.Stack;
 
 /**
  * Represents the game.
@@ -12,6 +13,7 @@ public class Game {
 
         private final HashMap<String, Room> rooms;
         private Room currentRoom;
+        private Stack<Room> previousRooms;
 
         /**
          * The default constructor.
@@ -19,6 +21,7 @@ public class Game {
         public Game() {
                 this.rooms = new HashMap<String, Room>();
                 this.currentRoom = null;
+                this.previousRooms = new Stack<Room>();
 
                 this.createRooms();
                 this.linkRooms();
@@ -48,8 +51,7 @@ public class Game {
          * @param exitRoomName
          *            the name of the exit room
          */
-        private void setRoomExit(final String roomName, final String direction,
-                        final String exitRoomName) {
+        private void setRoomExit(final String roomName, final String direction, final String exitRoomName) {
                 this.rooms.get(roomName).addExit(direction, this.rooms.get(exitRoomName));
         }
 
@@ -98,8 +100,7 @@ public class Game {
                 this.createRoom("OffscriptLock", "somewhere implementing a doorlock");
                 this.createRoom("OffscriptLockLockedroom", "in a locked room that is not anymore");
                 this.createRoom("OffscriptAlea", "somewhere implementing alea");
-                this.createRoom("OffscriptAleaRoomrandomizer",
-                                "in a weird room that will transport you somewhere else");
+                this.createRoom("OffscriptAleaRoomrandomizer", "in a weird room that will transport you somewhere else");
                 this.createRoom("OffscriptMovingcharacter", "somewhere implementing a moving character");
                 this.createRoom("OffscriptMovingcharacterMo", "in M-O's room");
 
@@ -199,12 +200,13 @@ public class Game {
         }
 
         /**
-         * Sets the current room.
+         * Sets the current room and stacks previous rooms.
          * 
          * @param room
          *            the destination room
          */
         public void goToRoom(final Room room) {
+                this.previousRooms.push(this.currentRoom);
                 this.currentRoom = room;
         }
 
@@ -219,6 +221,15 @@ public class Game {
         }
 
         /**
+         * Sets the current room to the previous room.
+         */
+        public void goToPreviousRoom() {
+                if (!this.previousRooms.empty()) {
+                        this.currentRoom = this.previousRooms.pop();
+                }
+        }
+
+        /**
          * Returns the current room's exit located in the given direction.
          * 
          * @param direction