1 files changed, 55 insertions, 0 deletions
diff --git a/src/domain/Percent.cs b/src/domain/Percent.cs
new file mode 100644
index 0000000..b8fea7e
--- /dev/null
+++ b/src/domain/Percent.cs
@@ -0,0 +1,55 @@
+namespace domain
+{
+  using System;
+
+  public class Percent
+  {
+    public static Percent Zero = new Percent(0);
+    decimal percentage;
+
+    public Percent(decimal percentage)
+    {
+      this.percentage = percentage;
+    }
+
+    public bool Equals(Percent other)
+    {
+      if (ReferenceEquals(null, other)) return false;
+      if (ReferenceEquals(this, other)) return true;
+      return other.percentage == percentage;
+    }
+
+    public override bool Equals(object obj)
+    {
+      if (ReferenceEquals(null, obj)) return false;
+      if (ReferenceEquals(this, obj)) return true;
+      if (obj.GetType() != typeof (Percent)) return false;
+      return Equals((Percent) obj);
+    }
+
+    public override int GetHashCode()
+    {
+      return percentage.GetHashCode();
+    }
+
+    public IQuantity Reduce(IQuantity original)
+    {
+      return new Quantity(PortionOf(original.Amount), original.Units);
+    }
+
+    public Percent Plus(Percent other)
+    {
+      return new Percent(percentage + other.percentage);
+    }
+
+    public decimal PortionOf(decimal amount)
+    {
+      return amount*percentage;
+    }
+
+    public override string ToString()
+    {
+      return string.Format("{0} %", percentage);
+    }
+  }
+}