Adding FiniteDuration instances

kernel/src/main/scala/cats/kernel/instances/finiteDuration.scala

@@ -0,0 +1,37 @@
+package cats.kernel
+package instances
+
+import scala.concurrent.duration.Duration
+
+import scala.concurrent.duration.FiniteDuration
+
+object finiteDuration extends FiniteDurationInstances
+
+trait FiniteDurationInstances {
+  implicit val catsKernelStdOrderForDuration: Order[FiniteDuration] with Hash[FiniteDuration] = new FiniteDurationOrder
+  implicit val catsKernelStdGroupForDuration: CommutativeGroup[FiniteDuration] = new FiniteDurationGroup
+}
+
+
+class FiniteDurationOrder extends Order[FiniteDuration] with Hash[FiniteDuration] {
+  def hash(x: FiniteDuration): Int = x.hashCode()
+
+  def compare(x: FiniteDuration, y: FiniteDuration): Int = x compare y
+
+  override def eqv(x: FiniteDuration, y: FiniteDuration): Boolean = x == y
+  override def neqv(x: FiniteDuration, y: FiniteDuration): Boolean = x != y
+  override def gt(x: FiniteDuration, y: FiniteDuration): Boolean = x > y
+  override def gteqv(x: FiniteDuration, y: FiniteDuration): Boolean = x >= y
+  override def lt(x: FiniteDuration, y: FiniteDuration): Boolean = x < y
+  override def lteqv(x: FiniteDuration, y: FiniteDuration): Boolean = x <= y
+
+  override def min(x: FiniteDuration, y: FiniteDuration): FiniteDuration = x min y
+  override def max(x: FiniteDuration, y: FiniteDuration): FiniteDuration = x max y
+}
+
+class FiniteDurationGroup extends CommutativeGroup[FiniteDuration] {
+  def empty: FiniteDuration = Duration.Zero
+  def inverse(x: FiniteDuration): FiniteDuration = -x
+  def combine(x: FiniteDuration, y: FiniteDuration): FiniteDuration = x + y
+  override def remove(x: FiniteDuration, y: FiniteDuration): FiniteDuration = x - y
+}