Add coursier.util.Gather

core/shared/src/main/scala/coursier/Fetch.scala

@@ -1,9 +1,8 @@
 package coursier
 
-import coursier.util.{EitherT, Monad}
+import coursier.util.{EitherT, Gather, Monad}
 
 import scala.language.higherKinds
-import scalaz.Nondeterminism
 
 object Fetch {
 
@@ -59,12 +58,12 @@ object Fetch {
     fetch: Content[F],
     extra: Content[F]*
   )(implicit
-    F: Nondeterminism[F]
+    F: Gather[F]
   ): Metadata[F] = {
 
     modVers =>
       F.map(
-        F.gatherUnordered {
+        F.gather {
           modVers.map {
             case (module, version) =>
               def get(fetch: Content[F]) = find(repositories, module, version, fetch)

core/shared/src/main/scala/coursier/util/Gather.scala

@@ -0,0 +1,18 @@
+package coursier.util
+
+import scala.language.higherKinds
+
+trait Gather[F[_]] extends Monad[F] {
+  def gather[A](elems: Seq[F[A]]): F[Seq[A]]
+}
+
+object Gather {
+
+  implicit def fromScalaz[F[_]](implicit N: scalaz.Nondeterminism[F]): Gather[F] =
+    new Gather[F] {
+      def point[A](a: A) = N.pure(a)
+      def bind[A, B](elem: F[A])(f: A => F[B]) = N.bind(elem)(f)
+      def gather[A](elems: Seq[F[A]]) = N.map(N.gather(elems))(l => l)
+    }
+
+}