Replace internal.Wrapper with RefType. closes #48, #53

docs/utils.md

@@ -94,7 +94,7 @@ xml("<a>link</a")
     ^
 
 scala> xpath("A//B/*[1]")
-res12: javax.xml.xpath.XPathExpression = com.sun.org.apache.xpath.internal.jaxp.XPathExpressionImpl@28c16218
+res12: javax.xml.xpath.XPathExpression = com.sun.org.apache.xpath.internal.jaxp.XPathExpressionImpl@433df4a4
 
 scala> xpath("A//B/*[1")
 <console>:18: error: XPath predicate failed: javax.xml.transform.TransformerException: Expected ], but found:

notes/0.2.2.markdown

@@ -1,5 +1,13 @@
 ### Changes
 
+* Introduce the `RefType` type class which abstracts over `shapeless.@@`
+  and `Refined` and that allows 3rd-party types to be used as result type
+  for refinements (e.g. [scalaz.@@][scalaz.@@]). `RefType` replaces the
+  now removed `internal.Wrapper` type class. ([#48], [#53], [#54])
 * Make the `Refined` constructor private ([#52])
 
+[#48]: https://github.com/fthomas/refined/issues/48
 [#52]: https://github.com/fthomas/refined/issues/52
+[#53]: https://github.com/fthomas/refined/issues/53
+[#54]: https://github.com/fthomas/refined/issues/54
+[scalaz.@@]: https://github.com/scalaz/scalaz/blob/v7.1.3/core/src/main/scala/scalaz/package.scala#L103

shared/src/main/scala/eu/timepit/refined/RefType.scala

@@ -0,0 +1,76 @@
+package eu.timepit.refined
+
+import eu.timepit.refined.internal.{ RefineAux, RefineMAux }
+import shapeless.tag.@@
+
+import scala.reflect.macros.blackbox
+
+trait RefType[F[_, _]] extends Serializable {
+
+  def unsafeWrap[T, P](t: T): F[T, P]
+
+  def unwrap[T, P](tp: F[T, P]): T
+
+  def unsafeWrapM[T: c.WeakTypeTag, P: c.WeakTypeTag](c: blackbox.Context)(t: c.Expr[T]): c.Expr[F[T, P]]
+
+  def unsafeRewrapM[T: c.WeakTypeTag, A: c.WeakTypeTag, B: c.WeakTypeTag](c: blackbox.Context)(ta: c.Expr[F[T, A]]): c.Expr[F[T, B]]
+
+  def refine[P]: RefineAux[F, P] =
+    new RefineAux[F, P](this)
+
+  def refineM[P]: RefineMAux[F, P] =
+    new RefineMAux[F, P]
+
+  def mapRefine[T, P, U](tp: F[T, P])(f: T => U)(implicit p: Predicate[P, U]): Either[String, F[U, P]] =
+    refine(f(unwrap(tp)))
+}
+
+object RefType {
+
+  def apply[F[_, _]](implicit rt: RefType[F]): RefType[F] = rt
+
+  implicit val refinedRefType: RefType[Refined] =
+    new RefType[Refined] {
+      override def unsafeWrap[T, P](t: T): Refined[T, P] =
+        Refined.unsafeApply(t)
+
+      override def unwrap[T, P](tp: Refined[T, P]): T =
+        tp.get
+
+      override def unsafeWrapM[T: c.WeakTypeTag, P: c.WeakTypeTag](c: blackbox.Context)(t: c.Expr[T]): c.Expr[Refined[T, P]] =
+        c.universe.reify(Refined.unsafeApply[T, P](t.splice))
+
+      override def unsafeRewrapM[T: c.WeakTypeTag, A: c.WeakTypeTag, B: c.WeakTypeTag](c: blackbox.Context)(ta: c.Expr[Refined[T, A]]): c.Expr[Refined[T, B]] =
+        c.universe.reify(ta.splice.asInstanceOf[Refined[T, B]])
+    }
+
+  implicit val tagRefType: RefType[@@] =
+    new RefType[@@] {
+      override def unsafeWrap[T, P](t: T): T @@ P =
+        t.asInstanceOf[T @@ P]
+
+      override def unwrap[T, P](tp: T @@ P): T =
+        tp
+
+      override def unsafeWrapM[T: c.WeakTypeTag, P: c.WeakTypeTag](c: blackbox.Context)(t: c.Expr[T]): c.Expr[T @@ P] =
+        c.universe.reify(t.splice.asInstanceOf[T @@ P])
+
+      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])
+    }
+
+  class RefTypeOps[F[_, _], T, P](tp: F[T, P])(implicit F: RefType[F]) {
+
+    def unwrap: T =
+      F.unwrap(tp)
+
+    def mapRefine[U](f: T => U)(implicit p: Predicate[P, U]): Either[String, F[U, P]] =
+      F.mapRefine(tp)(f)
+  }
+
+  object ops {
+
+    implicit def toRefTypeOps[F[_, _]: RefType, T, P](tp: F[T, P]): RefTypeOps[F, T, P] =
+      new RefTypeOps(tp)
+  }
+}

shared/src/main/scala/eu/timepit/refined/implicits.scala

@@ -11,10 +11,10 @@ object implicits {
    * `F[T, B]` if there is a valid inference rule `A ==> B`. If the
    * inference rule is invalid, compilation fails.
    */
-  implicit def autoInfer[T, A, B, F[_, _]](ta: F[T, A])(
+  implicit def autoInfer[F[_, _], T, A, B](ta: F[T, A])(
     implicit
-    ir: A ==> B, w: Wrapper[F]
-  ): F[T, B] = macro InferM.macroImpl[T, A, B, F]
+    ir: A ==> B, rt: RefType[F]
+  ): F[T, B] = macro InferM.macroImpl[F, T, A, B]
 
   /**
    * Implicitly wraps (at compile-time) a value of type `T` in
@@ -25,8 +25,8 @@ object implicits {
    */
   implicit def autoRefineV[T, P](t: T)(
     implicit
-    p: Predicate[P, T], w: Wrapper[Refined]
-  ): Refined[T, P] = macro RefineMAux.macroImpl[P, T, Refined]
+    p: Predicate[P, T], rt: RefType[Refined]
+  ): Refined[T, P] = macro RefineMAux.macroImpl[Refined, T, P]
 
   /**
    * Implicitly tags (at compile-time) a value of type `T` with `P` if `t`
@@ -37,6 +37,6 @@ object implicits {
    */
   implicit def autoRefineT[T, P](t: T)(
     implicit
-    p: Predicate[P, T], w: Wrapper[@@]
-  ): T @@ P = macro RefineMAux.macroImpl[P, T, @@]
+    p: Predicate[P, T], rt: RefType[@@]
+  ): T @@ P = macro RefineMAux.macroImpl[@@, T, P]
 }

shared/src/main/scala/eu/timepit/refined/internal/InferM.scala

@@ -7,16 +7,16 @@ import scala.reflect.macros.blackbox
 
 object InferM {
 
-  def macroImpl[T: c.WeakTypeTag, A: c.WeakTypeTag, B: c.WeakTypeTag, F[_, _]](c: blackbox.Context)(ta: c.Expr[F[T, A]])(
-    ir: c.Expr[A ==> B], w: c.Expr[Wrapper[F]]
+  def macroImpl[F[_, _], T: c.WeakTypeTag, A: c.WeakTypeTag, B: c.WeakTypeTag](c: blackbox.Context)(ta: c.Expr[F[T, A]])(
+    ir: c.Expr[A ==> B], rt: c.Expr[RefType[F]]
   ): c.Expr[F[T, B]] = {
     import c.universe._
 
     val inferenceRule = MacroUtils.eval(c)(ir)
 
     if (inferenceRule.isValid) {
-      val wrapper = MacroUtils.eval(c)(w)
-      wrapper.rewrapM(c)(ta)
+      val refType = MacroUtils.eval(c)(rt)
+      refType.unsafeRewrapM(c)(ta)
     } else
       c.abort(c.enclosingPosition, s"invalid inference: ${weakTypeOf[A]} ==> ${weakTypeOf[B]}")
   }

shared/src/main/scala/eu/timepit/refined/internal/RefineAux.scala

@@ -3,14 +3,16 @@ package internal
 
 /**
  * Helper class that allows the type `T` to be inferred from calls like
- * `[[refineV]][P](t)`. See [[http://tpolecat.github.io/2015/07/30/infer.html]]
- * for a detailed explanation of this trick.
+ * `[[RefType.refine]][P](t)`.
+ *
+ * See [[http://tpolecat.github.io/2015/07/30/infer.html]] for a detailed
+ * explanation of this trick.
  */
-final class RefineAux[P, F[_, _]] {
+final class RefineAux[F[_, _], P](rt: RefType[F]) {
 
-  def apply[T](t: T)(implicit p: Predicate[P, T], w: Wrapper[F]): Either[String, F[T, P]] =
+  def apply[T](t: T)(implicit p: Predicate[P, T]): Either[String, F[T, P]] =
     p.validate(t) match {
-      case None => Right(w.wrap(t))
+      case None => Right(rt.unsafeWrap(t))
       case Some(s) => Left(s)
     }
 }

shared/src/main/scala/eu/timepit/refined/internal/RefineMAux.scala

@@ -5,18 +5,20 @@ import scala.reflect.macros.blackbox
 
 /**
  * Helper class that allows the type `T` to be inferred from calls like
- * `[[refineMV]][P](t)`. See [[http://tpolecat.github.io/2015/07/30/infer.html]]
- * for a detailed explanation of this trick.
+ * `[[RefType.refineM]][P](t)`.
+ *
+ * See [[http://tpolecat.github.io/2015/07/30/infer.html]] for a detailed
+ * explanation of this trick.
  */
-final class RefineMAux[P, F[_, _]] {
+final class RefineMAux[F[_, _], P] {
 
-  def apply[T](t: T)(implicit p: Predicate[P, T], w: Wrapper[F]): F[T, P] = macro RefineMAux.macroImpl[P, T, F]
+  def apply[T](t: T)(implicit p: Predicate[P, T], rt: RefType[F]): F[T, P] = macro RefineMAux.macroImpl[F, T, P]
 }
 
 object RefineMAux {
 
-  def macroImpl[P: c.WeakTypeTag, T: c.WeakTypeTag, F[_, _]](c: blackbox.Context)(t: c.Expr[T])(
-    p: c.Expr[Predicate[P, T]], w: c.Expr[Wrapper[F]]
+  def macroImpl[F[_, _], T: c.WeakTypeTag, P: c.WeakTypeTag](c: blackbox.Context)(t: c.Expr[T])(
+    p: c.Expr[Predicate[P, T]], rt: c.Expr[RefType[F]]
   ): c.Expr[F[T, P]] = {
     import c.universe._
 
@@ -33,8 +35,8 @@ object RefineMAux {
 
     predicate.validate(tValue) match {
       case None =>
-        val wrapper = MacroUtils.eval(c)(w)
-        wrapper.wrapM(c)(t)
+        val refType = MacroUtils.eval(c)(rt)
+        refType.unsafeWrapM(c)(t)
       case Some(msg) => c.abort(c.enclosingPosition, msg)
     }
   }

shared/src/main/scala/eu/timepit/refined/package.scala

@@ -26,7 +26,7 @@ package object refined {
    * an `apply` method on it, allowing `refineV` to be called like in the
    * given example.
    */
-  def refineV[P]: RefineAux[P, Refined] = new RefineAux[P, Refined]
+  def refineV[P]: RefineAux[Refined, P] = RefType[Refined].refine[P]
 
   /**
    * Returns `t` with type `T @@ P` on the right if it satisfies the
@@ -47,7 +47,7 @@ package object refined {
    * `apply` method on it, allowing `refineT` to be called like in the given
    * example.
    */
-  def refineT[P]: RefineAux[P, @@] = new RefineAux[P, @@]
+  def refineT[P]: RefineAux[@@, P] = RefType[@@].refine[P]
 
   /**
    * Macro that returns `t` wrapped in `[[Refined]][T, P]` if it satisfies
@@ -67,7 +67,7 @@ package object refined {
    * has an `apply` method on it, allowing `refineMV` to be called like in
    * the given example.
    */
-  def refineMV[P]: RefineMAux[P, Refined] = new RefineMAux[P, Refined]
+  def refineMV[P]: RefineMAux[Refined, P] = RefType[Refined].refineM[P]
 
   /**
    * Macro that returns `t` with type `T @@ P` if it satisfies the predicate
@@ -88,14 +88,14 @@ package object refined {
    * `apply` method on it, allowing `refineMT` to be called like in the given
    * example.
    */
-  def refineMT[P]: RefineMAux[P, @@] = new RefineMAux[P, @@]
+  def refineMT[P]: RefineMAux[@@, P] = RefType[@@].refineM[P]
 
   @deprecated("refine is deprecated in favor of refineT", "0.2.0")
-  def refine[P]: RefineAux[P, @@] = new RefineAux[P, @@]
+  def refine[P]: RefineAux[@@, P] = refineT[P]
 
   @deprecated("refineLit is deprecated in favor of refineMT", "0.2.0")
-  def refineLit[P]: RefineMAux[P, @@] = new RefineMAux[P, @@]
+  def refineLit[P]: RefineMAux[@@, P] = refineMT[P]
 
   @deprecated("refineM is deprecated in favor of refineMV", "0.2.0")
-  def refineM[P]: RefineMAux[P, Refined] = new RefineMAux[P, Refined]
+  def refineM[P]: RefineMAux[Refined, P] = refineMV[P]
 }

shared/src/test/scala/eu/timepit/refined/RefTypeSpec.scala

@@ -0,0 +1,26 @@
+package eu.timepit.refined
+
+import eu.timepit.refined.RefType.ops._
+import eu.timepit.refined.numeric.Positive
+import org.scalacheck.Prop._
+import org.scalacheck.Properties
+import shapeless.tag.@@
+
+class RefTypeSpec extends Properties("RefType") {
+
+  def wrapperLaw[F[_, _]](implicit rt: RefType[F]) = forAll { (s: String) =>
+    rt.unwrap(rt.unsafeWrap(s)) == s
+  }
+
+  property("wrapLaw.Refined") = wrapperLaw[Refined]
+
+  property("wrapLaw.@@") = wrapperLaw[@@]
+
+  property("mapRefine.success") = secure {
+    RefType[Refined].refineM[Positive](5).mapRefine(_.toDouble).isRight
+  }
+
+  property("mapRefine.failure") = secure {
+    RefType[Refined].refineM[Positive](5).mapRefine(_ - 10).isLeft
+  }
+}