diff --git a/src/main/java/TP1/TurtleLexer.java b/src/main/java/TP1/TurtleLexer.java
index a43673f..396fa41 100644
--- a/src/main/java/TP1/TurtleLexer.java
+++ b/src/main/java/TP1/TurtleLexer.java
@@ -1,9 +1,23 @@
 package TP1;
 import org.antlr.runtime.CharStream;
+import org.antlr.runtime.Token;
+import org.antlr.runtime.TokenSource;
 
 
-public class TurtleLexer {
+public class TurtleLexer implements TokenSource {
     public TurtleLexer(CharStream input){
 
     }
+
+    @Override
+    public Token nextToken() {
+        // TODO Auto-generated method stub
+        throw new UnsupportedOperationException("Unimplemented method 'nextToken'");
+    }
+
+    @Override
+    public String getSourceName() {
+        // TODO Auto-generated method stub
+        throw new UnsupportedOperationException("Unimplemented method 'getSourceName'");
+    }
 }