zio · jdegoes · Nov 12, 2021 · Nov 7, 2021 · Nov 11, 2021 · Nov 11, 2021
diff --git a/core-tests/shared/src/test/scala/zio/ZIOBaseSpec.scala b/core-tests/shared/src/test/scala/zio/ZIOBaseSpec.scala
@@ -5,7 +5,14 @@ import zio.test._
 import scala.annotation.tailrec
 
 trait ZIOBaseSpec extends DefaultRunnableSpec {
-  override def aspects: List[TestAspectAtLeastR[Has[Live]]] =
+  override def aspects: List[TestAspect.WithOut[
+    Nothing,
+    TestEnvironment,
+    Nothing,
+    Any,
+    ({ type OutEnv[Env] = Env })#OutEnv,
+    ({ type OutErr[Err] = Err })#OutErr
+  ]] =
     if (TestPlatform.isJVM) List(TestAspect.timeout(120.seconds))
     else List(TestAspect.sequential, TestAspect.timeout(120.seconds))
 
@@ -30,7 +37,14 @@ trait ZIOBaseSpec extends DefaultRunnableSpec {
     case object supervision  extends ZIOTag { override val value = "supervision"  }
   }
 
-  def zioTag(zioTag: ZIOTag, zioTags: ZIOTag*): TestAspectPoly = {
+  def zioTag(zioTag: ZIOTag, zioTags: ZIOTag*): TestAspect.WithOut[
+    Nothing,
+    Any,
+    Nothing,
+    Any,
+    ({ type OutEnv[Env] = Env })#OutEnv,
+    ({ type OutErr[Err] = Err })#OutErr
+  ] = {
     val tags = zioTags.map(_.value) ++ getSubTags(zioTag) ++ zioTags.flatMap(getSubTags)
     TestAspect.tag(zioTag.value, tags.distinct: _*)
   }

diff --git a/core/shared/src/main/scala/zio/ZCompose.scala b/core/shared/src/main/scala/zio/ZCompose.scala
@@ -0,0 +1,191 @@
+/*
+ * Copyright 2017-2021 John A. De Goes and the ZIO Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package zio
+
+trait ZCompose[+LeftLower, -LeftUpper, LeftOut[In], +RightLower, -RightUpper, RightOut[In]] {
+  type Lower
+  type Upper
+  type Out[In]
+}
+
+object ZCompose extends ComposeLowPriorityImplicits {
+  type WithOut[LeftLower, LeftUpper, LeftOut[In], RightLower, RightUpper, RightOut[In], Lower0, Upper0, Out0[In]] =
+    ZCompose[LeftLower, LeftUpper, LeftOut, RightLower, RightUpper, RightOut] {
+      type Lower   = Lower0
+      type Upper   = Upper0
+      type Out[In] = Out0[In]
+    }
+
+  implicit def compose[
+    LeftLower,
+    LeftUpper,
+    LeftOut >: RightLower <: RightUpper,
+    RightLower,
+    RightUpper,
+    RightOut
+  ]: ZCompose.WithOut[
+    LeftLower,
+    LeftUpper,
+    ({ type Out[In] = LeftOut })#Out,
+    RightLower,
+    RightUpper,
+    ({ type Out[In] = RightOut })#Out,
+    LeftLower,
+    LeftUpper,
+    ({ type Out[In] = RightOut })#Out
+  ] =
+    new ZCompose[
+      LeftLower,
+      LeftUpper,
+      ({ type Out[In] = LeftOut })#Out,
+      RightLower,
+      RightUpper,
+      ({ type Out[In] = RightOut })#Out
+    ] {
+      type Lower   = LeftLower
+      type Upper   = LeftUpper
+      type Out[In] = RightOut
+    }
+
+  implicit def identity[LeftLower <: RightLower, LeftUpper, RightLower, RightUpper]: ZCompose.WithOut[
+    LeftLower,
+    LeftUpper,
+    Identity,
+    RightLower,
+    RightUpper,
+    Identity,
+    RightLower,
+    LeftUpper with RightUpper,
+    Identity
+  ] =
+    new ZCompose[
+      LeftLower,
+      LeftUpper,
+      Identity,
+      RightLower,
+      RightUpper,
+      Identity
+    ] {
+      type Lower   = RightLower
+      type Upper   = LeftUpper with RightUpper
+      type Out[In] = In
+    }
+
+  implicit def leftIdentity[LeftLower <: RightLower, LeftUpper, RightLower, RightUpper, RightOut]: ZCompose.WithOut[
+    LeftLower,
+    LeftUpper,
+    Identity,
+    RightLower,
+    RightUpper,
+    ({ type Out[In] = RightOut })#Out,
+    RightLower,
+    LeftUpper with RightUpper,
+    ({ type Out[In] = RightOut })#Out
+  ] =
+    new ZCompose[
+      LeftLower,
+      LeftUpper,
+      Identity,
+      RightLower,
+      RightUpper,
+      ({ type Out[In] = RightOut })#Out
+    ] {
+      type Lower   = RightLower
+      type Upper   = LeftUpper with RightUpper
+      type Out[In] = RightOut
+    }
+
+  implicit def rightIdentity[LeftLower, LeftUpper, LeftOut >: RightLower <: RightUpper, RightLower, RightUpper]
+    : ZCompose.WithOut[
+      LeftLower,
+      LeftUpper,
+      ({ type Out[In] = LeftOut })#Out,
+      RightLower,
+      RightUpper,
+      Identity,
+      LeftLower,
+      LeftUpper,
+      ({ type Out[In] = LeftOut })#Out
+    ] =
+    new ZCompose[
+      LeftLower,
+      LeftUpper,
+      ({ type Out[In] = LeftOut })#Out,
+      RightLower,
+      RightUpper,
+      Identity
+    ] {
+      type Lower   = LeftLower
+      type Upper   = LeftUpper
+      type Out[In] = LeftOut
+    }
+}
+
+trait ComposeLowPriorityImplicits {
+
+  type Identity[A] = A
+
+  implicit def identityLowPriority[LeftLowerElem, LeftUpperElem, RightLowerElem <: LeftLowerElem, RightUpperElem]
+    : ZCompose.WithOut[
+      LeftLowerElem,
+      LeftUpperElem,
+      Identity,
+      RightLowerElem,
+      RightUpperElem,
+      Identity,
+      LeftLowerElem,
+      LeftUpperElem with RightUpperElem,
+      Identity
+    ] =
+    new ZCompose[
+      LeftLowerElem,
+      LeftUpperElem,
+      Identity,
+      RightLowerElem,
+      RightUpperElem,
+      Identity
+    ] {
+      type Lower   = LeftLowerElem
+      type Upper   = LeftUpperElem with RightUpperElem
+      type Out[In] = In
+    }
+
+  implicit def leftIdentityLowPriority[LeftLower, LeftUpper, RightLower <: LeftLower, RightUpper, RightOut]
+    : ZCompose.WithOut[
+      LeftLower,
+      LeftUpper,
+      Identity,
+      RightLower,
+      RightUpper,
+      ({ type Out[In] = RightOut })#Out,
+      LeftLower,
+      LeftUpper with RightUpper,
+      ({ type Out[In] = RightOut })#Out
+    ] =
+    new ZCompose[
+      LeftLower,
+      LeftUpper,
+      Identity,
+      RightLower,
+      RightUpper,
+      ({ type Out[In] = RightOut })#Out
+    ] {
+      type Lower   = LeftLower
+      type Upper   = LeftUpper with RightUpper
+      type Out[In] = RightOut
+    }
+}
diff --git a/streams-tests/jvm/src/test/scala/zio/stream/ZPipelinePlatformSpecificSpec.scala b/streams-tests/jvm/src/test/scala/zio/stream/ZPipelinePlatformSpecificSpec.scala
@@ -8,7 +8,14 @@ import zio.test.Assertion._
 import java.util.zip.Deflater
 
 object ZPipelinePlatformSpecificSpec extends ZIOBaseSpec {
-  override def aspects: List[TestAspectAtLeastR[Has[Live]]] =
+  override def aspects: List[TestAspect.WithOut[
+    Nothing,
+    TestEnvironment,
+    Nothing,
+    Any,
+    ({ type OutEnv[Env] = Env })#OutEnv,
+    ({ type OutErr[Err] = Err })#OutErr
+  ]] =
     List(TestAspect.timeout(300.seconds))
 
   def spec: ZSpec[Environment, Failure] = suite("ZPipeline JVM")(

diff --git a/streams/shared/src/main/scala-2.11-2.12/zio/stream/ZPipelineVersionSpecific.scala b/streams/shared/src/main/scala-2.11-2.12/zio/stream/ZPipelineVersionSpecific.scala
@@ -23,7 +23,6 @@ import scala.annotation.unchecked.uncheckedVariance
 
 trait ZPipelineVersionSpecific[+LowerEnv, -UpperEnv, +LowerErr, -UpperErr, +LowerElem, -UpperElem] {
   self: ZPipeline[LowerEnv, UpperEnv, LowerErr, UpperErr, LowerElem, UpperElem] =>
-  import ZPipeline._
 
   /**
    * Composes two pipelines into one pipeline, by first applying the
@@ -40,9 +39,9 @@ trait ZPipelineVersionSpecific[+LowerEnv, -UpperEnv, +LowerErr, -UpperErr, +Lowe
       UpperElem2
     ]
   )(implicit
-    composeEnv: Compose[LowerEnv2, UpperEnv2, that.OutEnv, LowerEnv, UpperEnv, OutEnv] @uncheckedVariance,
-    composeErr: Compose[LowerErr2, UpperErr2, that.OutErr, LowerErr, UpperErr, OutErr] @uncheckedVariance,
-    composeElem: Compose[LowerElem2, UpperElem2, that.OutElem, LowerElem, UpperElem, OutElem] @uncheckedVariance
+    composeEnv: ZCompose[LowerEnv2, UpperEnv2, that.OutEnv, LowerEnv, UpperEnv, OutEnv] @uncheckedVariance,
+    composeErr: ZCompose[LowerErr2, UpperErr2, that.OutErr, LowerErr, UpperErr, OutErr] @uncheckedVariance,
+    composeElem: ZCompose[LowerElem2, UpperElem2, that.OutElem, LowerElem, UpperElem, OutElem] @uncheckedVariance
   ): ZPipeline.WithOut[
     composeEnv.Lower,
     composeEnv.Upper,
@@ -93,9 +92,9 @@ trait ZPipelineVersionSpecific[+LowerEnv, -UpperEnv, +LowerErr, -UpperErr, +Lowe
       UpperElem2
     ]
   )(implicit
-    composeEnv: Compose[LowerEnv, UpperEnv, OutEnv, LowerEnv2, UpperEnv2, that.OutEnv] @uncheckedVariance,
-    composeErr: Compose[LowerErr, UpperErr, OutErr, LowerErr2, UpperErr2, that.OutErr] @uncheckedVariance,
-    composeElem: Compose[LowerElem, UpperElem, OutElem, LowerElem2, UpperElem2, that.OutElem] @uncheckedVariance
+    composeEnv: ZCompose[LowerEnv, UpperEnv, OutEnv, LowerEnv2, UpperEnv2, that.OutEnv] @uncheckedVariance,
+    composeErr: ZCompose[LowerErr, UpperErr, OutErr, LowerErr2, UpperErr2, that.OutErr] @uncheckedVariance,
+    composeElem: ZCompose[LowerElem, UpperElem, OutElem, LowerElem2, UpperElem2, that.OutElem] @uncheckedVariance
   ): ZPipeline.WithOut[
     composeEnv.Lower,
     composeEnv.Upper,
@@ -146,9 +145,9 @@ trait ZPipelineVersionSpecific[+LowerEnv, -UpperEnv, +LowerErr, -UpperErr, +Lowe
       UpperElem2
     ]
   )(implicit
-    composeEnv: Compose[LowerEnv, UpperEnv, OutEnv, LowerEnv2, UpperEnv2, that.OutEnv] @uncheckedVariance,
-    composeErr: Compose[LowerErr, UpperErr, OutErr, LowerErr2, UpperErr2, that.OutErr] @uncheckedVariance,
-    composeElem: Compose[LowerElem, UpperElem, OutElem, LowerElem2, UpperElem2, that.OutElem] @uncheckedVariance
    composeEnv: ZCompose[LowerEnv, UpperEnv, OutEnv, LowerEnv2, UpperEnv2, that.OutEnv] @uncheckedVariance,
+    composeErr: ZCompose[LowerErr, UpperErr, OutErr, LowerErr2, UpperErr2, that.OutErr] @uncheckedVariance,
+    composeElem: ZCompose[LowerElem, UpperElem, OutElem, LowerElem2, UpperElem2, that.OutElem] @uncheckedVariance
   ): ZPipeline.WithOut[
     composeEnv.Lower,
     composeEnv.Upper,
@@ -197,9 +196,9 @@ trait ZPipelineVersionSpecific[+LowerEnv, -UpperEnv, +LowerErr, -UpperErr, +Lowe
       UpperElem2
     ]
   )(implicit
-    composeEnv: Compose[LowerEnv, UpperEnv, OutEnv, LowerEnv2, UpperEnv2, that.OutEnv] @uncheckedVariance,
-    composeErr: Compose[LowerErr, UpperErr, OutErr, LowerErr2, UpperErr2, that.OutErr] @uncheckedVariance,
-    composeElem: Compose[LowerElem, UpperElem, OutElem, LowerElem2, UpperElem2, that.OutElem] @uncheckedVariance
+    composeEnv: ZCompose[LowerEnv, UpperEnv, OutEnv, LowerEnv2, UpperEnv2, that.OutEnv] @uncheckedVariance,
+    composeErr: ZCompose[LowerErr, UpperErr, OutErr, LowerErr2, UpperErr2, that.OutErr] @uncheckedVariance,
+    composeElem: ZCompose[LowerElem, UpperElem, OutElem, LowerElem2, UpperElem2, that.OutElem] @uncheckedVariance
   ): ZPipeline.WithOut[
     composeEnv.Lower,
     composeEnv.Upper,
@@ -248,9 +247,9 @@ trait ZPipelineVersionSpecific[+LowerEnv, -UpperEnv, +LowerErr, -UpperErr, +Lowe
       UpperElem2
     ]
   )(implicit
-    composeEnv: Compose[LowerEnv2, UpperEnv2, that.OutEnv, LowerEnv, UpperEnv, OutEnv] @uncheckedVariance,
-    composeErr: Compose[LowerErr2, UpperErr2, that.OutErr, LowerErr, UpperErr, OutErr] @uncheckedVariance,
-    composeElem: Compose[LowerElem2, UpperElem2, that.OutElem, LowerElem, UpperElem, OutElem] @uncheckedVariance
+    composeEnv: ZCompose[LowerEnv2, UpperEnv2, that.OutEnv, LowerEnv, UpperEnv, OutEnv] @uncheckedVariance,
+    composeErr: ZCompose[LowerErr2, UpperErr2, that.OutErr, LowerErr, UpperErr, OutErr] @uncheckedVariance,
+    composeElem: ZCompose[LowerElem2, UpperElem2, that.OutElem, LowerElem, UpperElem, OutElem] @uncheckedVariance
   ): ZPipeline.WithOut[
     composeEnv.Lower,
     composeEnv.Upper,

diff --git a/streams/shared/src/main/scala-2.13+/zio/stream/ZPipelineCompanionVersionSpecific.scala b/streams/shared/src/main/scala-2.13+/zio/stream/ZPipelineCompanionVersionSpecific.scala
@@ -20,7 +20,6 @@ import zio._
 import zio.stacktracer.TracingImplicits.disableAutoTrace
 
 trait ZPipelineCompanionVersionSpecific {
-  import ZPipeline._
 
   implicit final class ZPipelineSyntax[LowerEnv, UpperEnv, LowerErr, UpperErr, LowerElem, UpperElem, OutEnv[
     Env
@@ -58,9 +57,9 @@ trait ZPipelineCompanionVersionSpecific {
         OutElem2
       ]
     )(implicit
-      composeEnv: Compose[LowerEnv2, UpperEnv2, OutEnv2, LowerEnv, UpperEnv, OutEnv],
-      composeErr: Compose[LowerErr2, UpperErr2, OutErr2, LowerErr, UpperErr, OutErr],
-      composeElem: Compose[LowerElem2, UpperElem2, OutElem2, LowerElem, UpperElem, OutElem]
+      composeEnv: ZCompose[LowerEnv2, UpperEnv2, OutEnv2, LowerEnv, UpperEnv, OutEnv],
+      composeErr: ZCompose[LowerErr2, UpperErr2, OutErr2, LowerErr, UpperErr, OutErr],
+      composeElem: ZCompose[LowerElem2, UpperElem2, OutElem2, LowerElem, UpperElem, OutElem]
     ): ZPipeline.WithOut[
       composeEnv.Lower,
       composeEnv.Upper,
@@ -94,9 +93,9 @@ trait ZPipelineCompanionVersionSpecific {
         OutElem2
       ]
     )(implicit
-      composeEnv: Compose[LowerEnv, UpperEnv, OutEnv, LowerEnv2, UpperEnv2, OutEnv2],
-      composeErr: Compose[LowerErr, UpperErr, OutErr, LowerErr2, UpperErr2, OutErr2],
-      composeElem: Compose[LowerElem, UpperElem, OutElem, LowerElem2, UpperElem2, OutElem2]
+      composeEnv: ZCompose[LowerEnv, UpperEnv, OutEnv, LowerEnv2, UpperEnv2, OutEnv2],
+      composeErr: ZCompose[LowerErr, UpperErr, OutErr, LowerErr2, UpperErr2, OutErr2],
+      composeElem: ZCompose[LowerElem, UpperElem, OutElem, LowerElem2, UpperElem2, OutElem2]
     ): ZPipeline.WithOut[
       composeEnv.Lower,
       composeEnv.Upper,
@@ -152,9 +151,9 @@ trait ZPipelineCompanionVersionSpecific {
         OutElem2
       ]
     )(implicit
-      composeEnv: Compose[LowerEnv, UpperEnv, OutEnv, LowerEnv2, UpperEnv2, OutEnv2],
-      composeErr: Compose[LowerErr, UpperErr, OutErr, LowerErr2, UpperErr2, OutErr2],
-      composeElem: Compose[LowerElem, UpperElem, OutElem, LowerElem2, UpperElem2, OutElem2]
+      composeEnv: ZCompose[LowerEnv, UpperEnv, OutEnv, LowerEnv2, UpperEnv2, OutEnv2],
+      composeErr: ZCompose[LowerErr, UpperErr, OutErr, LowerErr2, UpperErr2, OutErr2],
+      composeElem: ZCompose[LowerElem, UpperElem, OutElem, LowerElem2, UpperElem2, OutElem2]
     ): ZPipeline.WithOut[
       composeEnv.Lower,
       composeEnv.Upper,
@@ -186,9 +185,9 @@ trait ZPipelineCompanionVersionSpecific {
         OutElem2
       ]
     )(implicit
-      composeEnv: Compose[LowerEnv, UpperEnv, OutEnv, LowerEnv2, UpperEnv2, OutEnv2],
-      composeErr: Compose[LowerErr, UpperErr, OutErr, LowerErr2, UpperErr2, OutErr2],
-      composeElem: Compose[LowerElem, UpperElem, OutElem, LowerElem2, UpperElem2, OutElem2]
+      composeEnv: ZCompose[LowerEnv, UpperEnv, OutEnv, LowerEnv2, UpperEnv2, OutEnv2],
+      composeErr: ZCompose[LowerErr, UpperErr, OutErr, LowerErr2, UpperErr2, OutErr2],
+      composeElem: ZCompose[LowerElem, UpperElem, OutElem, LowerElem2, UpperElem2, OutElem2]
     ): ZPipeline.WithOut[
       composeEnv.Lower,
       composeEnv.Upper,
@@ -220,9 +219,9 @@ trait ZPipelineCompanionVersionSpecific {
         OutElem2
       ]
     )(implicit
-      composeEnv: Compose[LowerEnv2, UpperEnv2, OutEnv2, LowerEnv, UpperEnv, OutEnv],
-      composeErr: Compose[LowerErr2, UpperErr2, OutErr2, LowerErr, UpperErr, OutErr],
-      composeElem: Compose[LowerElem2, UpperElem2, OutElem2, LowerElem, UpperElem, OutElem]
+      composeEnv: ZCompose[LowerEnv2, UpperEnv2, OutEnv2, LowerEnv, UpperEnv, OutEnv],
+      composeErr: ZCompose[LowerErr2, UpperErr2, OutErr2, LowerErr, UpperErr, OutErr],
+      composeElem: ZCompose[LowerElem2, UpperElem2, OutElem2, LowerElem, UpperElem, OutElem]
     ): ZPipeline.WithOut[
       composeEnv.Lower,
       composeEnv.Upper,