Use generics in GenTokens

src/main/java/org/sablecc/sablecc/GenTokens.java

@@ -10,7 +10,7 @@ package org.sablecc.sablecc;
 import org.sablecc.sablecc.analysis.*;
 import org.sablecc.sablecc.node.*;
 import java.io.*;
-import java.util.LinkedList;
+import java.util.List;
 
 public class GenTokens extends DepthFirstAdapter
 {
@@ -71,16 +71,16 @@ public class GenTokens extends DepthFirstAdapter
 
     ARegExp regExp = (ARegExp) node.getRegExp();
 
-    LinkedList concats = regExp.getConcats();
+    List<PConcat> concats = regExp.getConcats();
 
     if(concats.size() == 1)
     {
-      AConcat concat = (AConcat)concats.getFirst();
-      LinkedList unExps = concat.getUnExps();
+      AConcat concat = (AConcat)concats.get(0);
+      List<PUnExp> unExps = concat.getUnExps();
 
       if(unExps.size() == 1)
       {
-        AUnExp unExp = (AUnExp) unExps.getFirst();
+        AUnExp unExp = (AUnExp) unExps.get(0);
 
         PBasic basic = unExp.getBasic();