add compact and compact! to SortedArray

lib/sorted_containers/sorted_array.rb

@@ -335,6 +335,25 @@ def combination(n, &block)
       to_a.combination(n, &block)
     end
 
+    # Returns a new SortedArray containing of non-nil elements.
+    #
+    # @return [SortedArray] The compacted array.
+    def compact
+      new_instance = self.class.new
+      new_instance.update(to_a.compact)
+      new_instance
+    end
+
+    # Removes nil elements from the SortedArray.
+    #
+    # @return [SortedArray] The compacted array.
+    def compact!
+      values = to_a.compact
+      clear
+      update(values)
+      self
+    end
+
     # rubocop:enable Naming/MethodParameterName
 
     # Returns a string representation of the sorted array.

spec/sorted_array_spec.rb

@@ -541,6 +541,47 @@
     end
   end
 
+  describe "compact" do
+    it "should remove nil values from the array" do
+      # SortedArray can only contain comparable values
+      # so the only way to have nil values is for all values to be nil
+      array = SortedContainers::SortedArray.new([nil, nil, nil, nil, nil])
+      expect(array.compact).to eq(SortedContainers::SortedArray.new)
+    end
+
+    it "should return the array if there are no nil values" do
+      array = SortedContainers::SortedArray.new([1, 2, 3, 4, 5])
+      expect(array.compact).to eq(array)
+    end
+
+    it "should return the array if the array is empty" do
+      array = SortedContainers::SortedArray.new
+      expect(array.compact).to eq(array)
+    end
+  end
+
+  describe "compact!" do
+    it "should remove nil values from the array" do
+      # SortedArray can only contain comparable values
+      # so the only way to have nil values is for all values to be nil
+      array = SortedContainers::SortedArray.new([nil, nil, nil, nil, nil])
+      array.compact!
+      expect(array).to eq(SortedContainers::SortedArray.new)
+    end
+
+    it "should return the array if there are no nil values" do
+      array = SortedContainers::SortedArray.new([1, 2, 3, 4, 5])
+      array.compact!
+      expect(array).to eq(SortedContainers::SortedArray.new([1, 2, 3, 4, 5]))
+    end
+
+    it "should return the array if the array is empty" do
+      array = SortedContainers::SortedArray.new
+      array.compact!
+      expect(array).to eq(SortedContainers::SortedArray.new)
+    end
+  end
+
   describe "load_factor" do
     it "should set the load factor to the provided value" do
       array = SortedContainers::SortedArray.new([], load_factor: 100)