add operations

geocrystal · Apr 30, 2024 · df64a82 · df64a82
1 parent 6b31331
commit df64a82
Show file tree

Hide file tree

Showing 2 changed files with 19 additions and 0 deletions.
diff --git a/spec/ring_area_spec.cr b/spec/ring_area_spec.cr
@@ -33,4 +33,13 @@ describe RingArea do
     it { (ring_area_1 == ring_area_2).should be_false }
     it { (ring_area_1 > ring_area_2).should be_true }
   end
+
+  describe "operations" do
+    ring_area_1 = RingArea.ring_area(coordinates)
+    ring_area_2 = RingArea.ring_area(other_coordinates)
+
+    it { (ring_area_1 + ring_area_2).should be_a(RingArea::Area) }
+    it { (ring_area_1 + ring_area_2).to_meters.should eq(7798346482558.176) }
+    it { (ring_area_1 - ring_area_2).to_meters.should eq(7699436737396.736) }
+  end
 end
diff --git a/src/ring_area/area.cr b/src/ring_area/area.cr
@@ -18,5 +18,15 @@ module RingArea
     def <=>(other : RingArea::Area)
       area <=> other.area
     end
+
+    # Adds the value of `self` to *other*.
+    def +(other : RingArea::Area) : RingArea::Area
+      RingArea::Area.new(self.area + other.area)
+    end
+
+    # Removes the value of *other* from `self`.
+    def -(other : RingArea::Area) : RingArea::Area
+      RingArea::Area.new(self.area - other.area)
+    end
   end
 end