Enable rootOption on FilePath

core/src/main/scala/eyrie/instances/ConvertibleInstances.scala

@@ -4,7 +4,7 @@ import eyrie.ops.Convertible
 
 private[eyrie]
 trait ConvertibleByAttributeInstances {
-  implicit def eyrieByAttributeInstance[Attr[_], A, B](
+  implicit def eyrieConvertibleByAttributeInstance[Attr[_], A, B](
     implicit F: Convertible.Aux[Attr, _, A, B]
   ): Convertible.ByAttribute.Aux[Attr, A, B] =
     new Convertible.ByAttribute[Attr, A] {
@@ -23,7 +23,7 @@ trait ConvertibleByAttributeInstances {
 
 private[eyrie]
 trait ConvertibleByQualityInstances {
-  implicit def eyrieByQualityInstance[Attr[_], Param, A, B](
+  implicit def eyrieConvertibleByQualityInstance[Attr[_], Param, A, B](
     implicit F: Convertible.Aux[Attr, Param, A, B]
   ): Convertible.ByQuality.Aux[Attr[Param], A, B] =
     new Convertible.ByQuality[Attr[Param], B] {

core/src/main/scala/eyrie/instances/DescendantInstances.scala

@@ -8,7 +8,7 @@ import scala.Function.const
 
 private[eyrie]
 trait DescendantInstances {
-  implicit def eyrieSubdivisionBasedInstance[A, LA, RA, B](
+  implicit def eyrieDescendantBasedInstance[A, LA, RA, B](
     implicit
     A: Subdivision[A, LA, RA],
     LA: Descendant[LA, B],
@@ -19,10 +19,18 @@ trait DescendantInstances {
       def root: A => B =
         A.subdivide(_).fold(LA.root, RA.root)
     }
+
+  implicit def eyrieNonDescendantBasedInstance[A, LA, RA](
+    implicit
+    A: Subdivision[A, LA, RA],
+    LA: NonDescendant[LA],
+    RA: NonDescendant[RA]
+  ): NonDescendant[A] =
+    eyrieDescendantBasedInstance[A, LA, RA, Nothing]
 }
 
 private[eyrie]
-trait DescendantByInputInstances extends LowPriorityDescendantByInputInstances {
+trait DescendantByInputInstances {
   implicit def eyrieTrivialByInputInstance[A](
     implicit A: TrivialDescendant[A]
   ): Descendant.ByInput.Aux[A, A] =
@@ -39,11 +47,8 @@ trait DescendantByInputInstances extends LowPriorityDescendantByInputInstances {
       def root: A => A =
         A.root
     }
-}
 
-private[eyrie]
-trait LowPriorityDescendantByInputInstances {
-  implicit def eyrieByInputInstance[A, B](
+  implicit def eyrieDescendantByInputInstance[A, B](
     implicit A: Descendant[A, B]
   ): Descendant.ByInput.Aux[A, B] =
     new Descendant.ByInput[A] {
@@ -58,7 +63,7 @@ trait LowPriorityDescendantByInputInstances {
 
 private[eyrie]
 trait PotentialDescendantInstances {
-  implicit def eyrieLeftSubdivisionBasedInstance[A, LA, RA, B](
+  implicit def eyrieLeftDescendantBasedInstance[A, LA, RA, B](
     implicit
     A: Subdivision[A, LA, RA],
     LA: Descendant[LA, B],
@@ -70,7 +75,7 @@ trait PotentialDescendantInstances {
         A.subdivide(_).fold(LA.root >>> (Some(_)), const(None))
     }
 
-  implicit def eyrieRightSubdivisionBasedInstance[A, LA, RA, B](
+  implicit def eyrieRightDescendantBasedInstance[A, LA, RA, B](
     implicit
     A: Subdivision[A, LA, RA],
     LA: NonDescendant[LA],
@@ -85,7 +90,7 @@ trait PotentialDescendantInstances {
 
 private[eyrie]
 trait PotentialDescendantByInputInstances {
-  implicit def eyrieByInputInstance[A, D](
+  implicit def eyriePotentialDescendantByInputInstance[A, D](
     implicit A: PotentialDescendant[A, D]
   ): PotentialDescendant.ByInput.Aux[A, D] =
     new PotentialDescendant.ByInput[A] {

core/src/main/scala/eyrie/instances/DiSuccessorInstances.scala

@@ -7,7 +7,7 @@ import eyrie.ops._
 
 private[eyrie]
 trait DiSuccessorInstances {
-  implicit def eyrieSubdivisionBasedInstance[A, LA, RA, LB, RB, C](
+  implicit def eyrieSuccessorBasedInstance[A, LA, RA, LB, RB, C](
     implicit
     A: Subdivision[A, LA, RA],
     LA: Successor[LA, LB, C],
@@ -26,7 +26,7 @@ trait DiSuccessorInstances {
 
 private[eyrie]
 trait DiSuccessorByInputInstances {
-  implicit def eyrieByInputInstance[A, L, R, C](
+  implicit def eyrieDiSuccessorByInputInstance[A, L, R, C](
     implicit A: DiSuccessor[A, L, R, C]
   ): DiSuccessor.ByInput.Aux[A, L, R, C] =
     new DiSuccessor.ByInput[A] {
@@ -49,7 +49,7 @@ trait DiSuccessorByInputInstances {
 
 private[eyrie]
 trait DiPotentialSuccessorInstances {
-  implicit def eyrieSubdivisionBasedInstance[A, L, R, C](
+  implicit def eyriePotentialSuccessorBasedInstance[A, L, R, C](
     implicit
     A: Subdivision[A, L, R],
     L: PotentialSuccessor[L, C],
@@ -68,7 +68,7 @@ trait DiPotentialSuccessorInstances {
 
 private[eyrie]
 trait DiPotentialSuccessorByInputInstances {
-  implicit def eyrieByInputInstance[A, L, R, C](
+  implicit def eyrieDiPotentialSuccessorByInputInstance[A, L, R, C](
     implicit A: DiPotentialSuccessor[A, L, R, C]
   ): DiPotentialSuccessor.ByInput.Aux[A, L, R, C] =
     new DiPotentialSuccessor.ByInput[A] {

core/src/main/scala/eyrie/instances/SubdivisionInstances.scala

@@ -4,7 +4,7 @@ import eyrie.ops.Subdivision
 
 private[eyrie]
 trait SubdivisionByAttributeInstances {
-  implicit def eyrieByAttributeInstance[Attr[_], A, L, R](
+  implicit def eyrieSubdivisionByAttributeInstance[Attr[_], A, L, R](
     implicit F: Subdivision.Aux[Attr, A, L, R]
   ): Subdivision.ByAttribute.Aux[Attr, A, L, R] =
     new Subdivision.ByAttribute[Attr, A] {
@@ -21,7 +21,7 @@ trait SubdivisionByAttributeInstances {
 
 private[eyrie]
 trait SubdivisionByInputInstances {
-  implicit def eyrieByInputInstance[Attr[_], A, L, R](
+  implicit def eyrieSubdivisionByInputInstance[Attr[_], A, L, R](
     implicit F: Subdivision.Aux[Attr, A, L, R]
   ): Subdivision.ByInput.Aux[Attr, A, L, R] =
     new Subdivision.ByInput[A] {

core/src/main/scala/eyrie/instances/SuccessorInstances.scala

@@ -25,7 +25,7 @@ trait SuccessorInstances {
 
 private[eyrie]
 trait SuccessorByInputInstances {
-  implicit def eyrieByInputInstance[A, B, C](implicit A: Successor[A, B, C]): Successor.ByInput.Aux[A, B, C] =
+  implicit def eyrieSuccessorByInputInstance[A, B, C](implicit A: Successor[A, B, C]): Successor.ByInput.Aux[A, B, C] =
     new Successor.ByInput[A] {
       override
       type Prefix = B
@@ -76,7 +76,9 @@ trait PotentialSuccessorInstances {
 
 private[eyrie]
 trait PotentialSuccessorByInputInstances {
-  implicit def eyrieByInputInstance[A, C](implicit A: PotentialSuccessor[A, C]): PotentialSuccessor.ByInput.Aux[A, C] =
+  implicit def eyriePotentialSuccessorByInputInstance[A, C](
+    implicit A: PotentialSuccessor[A, C]
+  ): PotentialSuccessor.ByInput.Aux[A, C] =
     new PotentialSuccessor.ByInput[A] {
       override
       type Segment = C

file/src/test/scala/eyrie/file/test/PotentialDescendantSpec.scala

@@ -12,16 +12,24 @@ import org.scalatest.junit.JUnitRunner
 object PotentialDescendantSpec {
   val nonEmpty: FilePath.NonEmpty[Sys] =
     Internal.AbsoluteFile(Paths.get("a/b/c").toAbsolutePath)
+
+  val filePath: FilePath[Sys] =
+    Internal.RootDirectory(Paths.get("a/b/c").getRoot)
 }
 
 @RunWith(classOf[JUnitRunner])
 class PotentialDescendantSpec extends FreeSpec {
   import PotentialDescendantSpec._
   import eyrie.syntax.potentialDescendant._
 
-  "File.Absolute" - {
+  "FilePath.Absolute" - {
     "rootOption should be Option of RootDirectory" in {
       nonEmpty.rootOption: Option[RootDirectory[Sys]]
     }
   }
+  "FilePath" - {
+    "rootOption should be Option of RootDirectory" in {
+      filePath.rootOption: Option[RootDirectory[Sys]]
+    }
+  }
 }