Merge pull request #179 from fthomas/topic/equal-show

Add scalaz.{Equal, Show} instances
fthomas · Jun 16, 2016 · 77ac14b · 77ac14b
2 parents 05dc4e8 + 276c2f9
commit 77ac14b
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diff --git a/contrib/scalaz/shared/src/main/scala/eu/timepit/refined/scalaz/package.scala b/contrib/scalaz/shared/src/main/scala/eu/timepit/refined/scalaz/package.scala
@@ -1,6 +1,8 @@
 package eu.timepit.refined
 
 import _root_.scalaz.@@
+import _root_.scalaz.Equal
+import _root_.scalaz.Show
 import eu.timepit.refined.api.RefType
 import scala.reflect.macros.blackbox
 
@@ -23,4 +25,10 @@ package object scalaz {
       override def unsafeRewrapM[T: c.WeakTypeTag, A: c.WeakTypeTag, B: c.WeakTypeTag](c: blackbox.Context)(ta: c.Expr[T @@ A]): c.Expr[T @@ B] =
         c.universe.reify(ta.splice.asInstanceOf[T @@ B])
     }
+
+  implicit def refTypeEqual[F[_, _], T: Equal, P](implicit rt: RefType[F]): Equal[F[T, P]] =
+    Equal.equalBy(rt.unwrap)
+
+  implicit def refTypeShow[F[_, _], T, P](implicit rt: RefType[F], s: Show[T]): Show[F[T, P]] =
+    Show.shows(tp => s.shows(rt.unwrap(tp)))
 }
diff --git a/contrib/scalaz/shared/src/test/scala/eu/timepit/refined/scalaz/RefTypeSpecScalazTag.scala b/contrib/scalaz/shared/src/test/scala/eu/timepit/refined/scalaz/RefTypeSpecScalazTag.scala
@@ -1,6 +1,9 @@
 package eu.timepit.refined.scalaz
 
 import _root_.scalaz.@@
+import _root_.scalaz.std.anyVal._
+import _root_.scalaz.syntax.equal._
+import _root_.scalaz.syntax.show._
 import eu.timepit.refined.TestUtils._
 import eu.timepit.refined.api.{ RefType, RefTypeSpec }
 import eu.timepit.refined.numeric._
@@ -23,4 +26,17 @@ class RefTypeSpecScalazTag extends RefTypeSpec[@@]("scalaz.@@") {
   property("(T @@ P) <!: T") = wellTyped {
     illTyped("implicitly[(Int @@ Positive) <:< Int]", "Cannot prove.*")
   }
+
+  property("scalaz.Equal") = secure {
+    type PosInt = Int @@ Positive
+    val x: PosInt = 5
+    val y: PosInt = 5
+    x === y
+  }
+
+  property("scalaz.Show") = secure {
+    type PosInt = Int @@ Positive
+    val x: PosInt = 5
+    x.shows ?= "5"
+  }
 }
diff --git a/notes/0.5.0.markdown b/notes/0.5.0.markdown
@@ -17,6 +17,9 @@
 * Renamed `RefinePartiallyApplied.force` to `unsafeFrom` and add
   `ApplyRefPartiallyApplied.unsafeFrom`. ([#175])
 * Add `Arbitrary` instance for `Equal`. ([#170])
+* Add `scalaz.Equal` and `scalaz.Show` instances for refined types.
+  These instances use the respective instances of the base types.
+  ([#179])
 
 ### Updates
 
@@ -32,3 +35,4 @@
 [#172]: https://github.com/fthomas/refined/pull/172
 [#175]: https://github.com/fthomas/refined/pull/175
 [#178]: https://github.com/fthomas/refined/pull/178
+[#179]: https://github.com/fthomas/refined/pull/179