Minor refactoring.

src/main/java/ch/fritteli/labyrinth/model/Direction.java

@@ -1,21 +1,10 @@
 package ch.fritteli.labyrinth.model;
 
-import lombok.NonNull;
-
-import java.util.function.UnaryOperator;
-
 public enum Direction {
-    TOP(position -> position.withY(position.getY() - 1)),
+    TOP,
-    BOTTOM(position -> position.withY(position.getY() + 1)),
+    BOTTOM,
-    LEFT(position -> position.withX(position.getX() - 1)),
+    LEFT,
-    RIGHT(position -> position.withX(position.getX() + 1));
+    RIGHT;
-
-    @NonNull
-    private final UnaryOperator<Position> translation;
-
-    Direction(@NonNull final UnaryOperator<Position> translation) {
-        this.translation = translation;
-    }
 
     public Direction invert() {
         switch (this) {
@@ -30,8 +19,4 @@ public enum Direction {
         }
         throw new IllegalStateException("Programming error: Not all enum values covered in enum Direction#invert()!");
     }
-
-    public Position translate(@NonNull final Position position) {
-        return this.translation.apply(position);
-    }
 }

src/main/java/ch/fritteli/labyrinth/model/Labyrinth.java

@@ -126,7 +126,7 @@ public class Labyrinth {
                 if (directionToDigTo.isDefined()) {
                     final Direction digTo = directionToDigTo.get();
                     final Direction digFrom = digTo.invert();
-                    final Position neighborPosition = digTo.translate(currentPosition);
+                    final Position neighborPosition = currentPosition.move(digTo);
                     final Tile neighborTile = Labyrinth.this.getTileAt(neighborPosition);
                     if (currentTile.digTo(digTo) && neighborTile.digFrom(digFrom)) {
                         // all ok!

src/main/java/ch/fritteli/labyrinth/model/Position.java

@@ -1,5 +1,6 @@
 package ch.fritteli.labyrinth.model;
 
+import lombok.NonNull;
 import lombok.Value;
 import lombok.With;
 
@@ -8,4 +9,19 @@ import lombok.With;
 public class Position {
     int x;
     int y;
+
+    public Position move(@NonNull final Direction direction) {
+        switch (direction) {
+            case BOTTOM:
+                return this.withY(this.y + 1);
+            case LEFT:
+                return this.withX(this.x - 1);
+            case RIGHT:
+                return this.withX(this.x + 1);
+            case TOP:
+                return this.withY(this.y - 1);
+            default:
+                throw new IllegalStateException("Programming error: Not all Direction enum values covered in Position#move(Direction)!");
+        }
+    }
 }

src/main/java/ch/fritteli/labyrinth/renderer/pdf/Generator.java

@@ -223,7 +223,7 @@ class Generator {
         final Tile currentTile = this.labyrinth.getTileAt(currentPosition);
         for (final Direction direction : Direction.values()) {
             if (!currentTile.hasWallAt(direction)) {
-                final Position position = direction.translate(currentPosition);
+                final Position position = currentPosition.move(direction);
                 final Tile tileAtPosition = this.labyrinth.getTileAtOrNull(position);
                 if (position.equals(previousPosition) || tileAtPosition == null) {
                     continue;