1 files changed, 34 insertions, 0 deletions
diff --git a/pos.rb b/pos.rb
new file mode 100644
index 0000000..2712931
--- /dev/null
+++ b/pos.rb
@@ -0,0 +1,34 @@
+Pos = Struct.new(:x, :y) do
+  def move(dir)
+    case dir
+    when :up
+      Pos.new(x, y - 1)
+    when :right
+      Pos.new(x + 1, y)
+    when :down
+      Pos.new(x, y + 1)
+    when :left
+      Pos.new(x - 1, y)
+    end
+  end
+
+  def dir_from(pos)
+    diff_x = x - pos.x
+    diff_y = y - pos.y
+
+    case Pos.new(diff_x, diff_y)
+    when Pos.new(0, -1)
+      :up
+    when Pos.new(1, 0)
+      :right
+    when Pos.new(0, 1)
+      :down
+    when Pos.new(-1, 0)
+      :left
+    end
+  end
+
+  def to_s()
+    "(#{x}, #{y})"
+  end
+end