1 files changed, 17 insertions, 1 deletions
diff --git a/lib/range_ext.rb b/lib/range_ext.rb
index f1df5e70d..e7e0e903f 100644
--- a/lib/range_ext.rb
+++ b/lib/range_ext.rb
@@ -1,8 +1,24 @@
 class Range
 
   def intersection(other)
-    return nil if (self.max < other.min or other.max < self.min)
+    return nil unless intersect?(other)
     [self.min, other.min].max..[self.max, other.max].min
   end
   alias_method :&, :intersection
+
+  def intersect?(other)
+    self.max > other.min and other.max > self.min
+  end
+
+  def remove(other)
+    return self if (self.max < other.min or other.max < self.min)
+
+    [].tap do |remaining|
+      remaining << (self.min..other.min-1) if self.min < other.min
+      remaining << (other.max+1..self.max) if other.max < self.max
+      remaining.compact!
+    end
+  end
+  alias_method :-, :remove
+
 end