Apply syntax for tuples, fixes #1363

.jvmopts

@@ -1,12 +1,9 @@
-# see https://weblogs.java.net/blog/kcpeppe/archive/2013/12/11/case-study-jvm-hotspot-flags
 -Dfile.encoding=UTF8
 -Xms1G
 -Xmx6G
 -XX:MaxPermSize=512M
 -XX:ReservedCodeCacheSize=250M
 -XX:+TieredCompilation
 -XX:-UseGCOverheadLimit
-# effectively adds GC to Perm space
 -XX:+CMSClassUnloadingEnabled
-# must be enabled for CMSClassUnloadingEnabled to work
 -XX:+UseConcMarkSweepGC

core/src/main/scala/cats/data/EitherT.scala

@@ -175,7 +175,7 @@ final case class EitherT[F[_], A, B](value: F[Either[A, B]]) {
    * scala> val v1: Validated[NonEmptyList[Error], Int] = Validated.Invalid(NonEmptyList.of("error 1"))
    * scala> val v2: Validated[NonEmptyList[Error], Int] = Validated.Invalid(NonEmptyList.of("error 2"))
    * scala> val eithert: EitherT[Option, Error, Int] = EitherT(Some(Either.left("error 3")))
-   * scala> eithert.withValidated { v3 => (v1 |@| v2 |@| v3.leftMap(NonEmptyList.of(_))).map{ case (i, j, k) => i + j + k } }
+   * scala> eithert.withValidated { v3 => (v1, v2, v3.leftMap(NonEmptyList.of(_))).mapN { case (i, j, k) => i + j + k } }
    * res0: EitherT[Option, NonEmptyList[Error], Int] = EitherT(Some(Left(NonEmptyList(error 1, error 2, error 3))))
    * }}}
    */

core/src/main/scala/cats/syntax/all.scala

@@ -42,7 +42,6 @@ trait AllSyntax
     with StrongSyntax
     with TraverseFilterSyntax
     with TraverseSyntax
-    with TupleSyntax
     with ValidatedSyntax
     with VectorSyntax
     with WriterSyntax

core/src/main/scala/cats/syntax/apply.scala

@@ -1,7 +1,7 @@
 package cats
 package syntax
 
-trait ApplySyntax {
+trait ApplySyntax extends TupleCartesianSyntax {
   implicit final def catsSyntaxApply[F[_], A](fa: F[A])(implicit F: Apply[F]): Apply.Ops[F, A] =
     new Apply.Ops[F, A] {
       val self = fa

core/src/main/scala/cats/syntax/package.scala

@@ -42,7 +42,6 @@ package object syntax {
   object monadTrans extends MonadTransSyntax
   object traverse extends TraverseSyntax
   object traverseFilter extends TraverseFilterSyntax
-  object tuple extends TupleSyntax
   object validated extends ValidatedSyntax
   object vector extends VectorSyntax
   object writer extends WriterSyntax

free/src/test/scala/cats/free/FreeApplicativeTests.scala

@@ -73,7 +73,7 @@ class FreeApplicativeTests extends CatsSuite {
     // fixed by #568
     val fli1 = FreeApplicative.lift[List, Int](List(1, 3, 5, 7))
     val fli2 = FreeApplicative.lift[List, Int](List(1, 3, 5, 7))
-    (fli1 |@| fli2).map(_ + _)
+    (fli1, fli2).mapN(_ + _)
   }
 
   test("FreeApplicative#analyze") {

project/Boilerplate.scala

@@ -238,15 +238,21 @@ object Boilerplate {
 
       val map =
         if (arity == 1) s"def map[Z](f: (${`A..N`}) => Z)(implicit functor: Functor[F]): F[Z] = functor.map($tupleArgs)(f)"
-        else s"def map$arity[Z](f: (${`A..N`}) => Z)(implicit functor: Functor[F], cartesian: Cartesian[F]): F[Z] = Cartesian.map$arity($tupleArgs)(f)"
+        else s"def mapN[Z](f: (${`A..N`}) => Z)(implicit functor: Functor[F]): F[Z] = Cartesian.map$arity($tupleArgs)(f)"
 
       val contramap =
         if (arity == 1) s"def contramap[Z](f: Z => (${`A..N`}))(implicit contravariant: Contravariant[F]): F[Z] = contravariant.contramap($tupleArgs)(f)"
-        else s"def contramap$arity[Z](f: Z => (${`A..N`}))(implicit contravariant: Contravariant[F], cartesian: Cartesian[F]): F[Z] = Cartesian.contramap$arity($tupleArgs)(f)"
+        else s"def contramapN[Z](f: Z => (${`A..N`}))(implicit contravariant: Contravariant[F]): F[Z] = Cartesian.contramap$arity($tupleArgs)(f)"
 
       val imap =
         if (arity == 1) s"def imap[Z](f: (${`A..N`}) => Z)(g: Z => (${`A..N`}))(implicit invariant: Invariant[F]): F[Z] = invariant.imap($tupleArgs)(f)(g)"
-        else s"def imap$arity[Z](f: (${`A..N`}) => Z)(g: Z => (${`A..N`}))(implicit invariant: Invariant[F], cartesian: Cartesian[F]): F[Z] = Cartesian.imap$arity($tupleArgs)(f)(g)"
+        else s"def imapN[Z](f: (${`A..N`}) => Z)(g: Z => (${`A..N`}))(implicit invariant: Invariant[F]): F[Z] = Cartesian.imap$arity($tupleArgs)(f)(g)"
+
+      val tupled = if (arity != 1) {
+        s"def tupled(implicit invariant: Invariant[F]): F[(${`A..N`})] = Cartesian.tuple$n($tupleArgs)"
+      } else {
+        ""
+      }
 
       block"""
         |package cats
@@ -255,13 +261,15 @@ object Boilerplate {
         |import cats.functor.{Contravariant, Invariant}
         |
         |trait TupleCartesianSyntax {
-        -  implicit def catsSyntaxTuple${arity}Cartesian[F[_], ${`A..N`}]($tupleTpe): Tuple${arity}CartesianOps[F, ${`A..N`}] = new Tuple${arity}CartesianOps(t$arity)
+        -  implicit def catsSyntaxTuple${arity}Cartesian[F[_], ${`A..N`}]($tupleTpe)(implicit C: Cartesian[F]): Tuple${arity}CartesianOps[F, ${`A..N`}] = new Tuple${arity}CartesianOps(t$arity, C)
         |}
         |
-        -private[syntax] final class Tuple${arity}CartesianOps[F[_], ${`A..N`}]($tupleTpe) {
+        -private[syntax] final class Tuple${arity}CartesianOps[F[_], ${`A..N`}]($tupleTpe, C: Cartesian[F]) {
+        -  implicit val cartesian: Cartesian[F] = C
         -  $map
         -  $contramap
         -  $imap
+        -  $tupled
         -  def apWith[Z](f: F[(${`A..N`}) => Z])(implicit apply: Apply[F]): F[Z] = apply.ap$n(f)($tupleArgs)
         -}
         |

tests/src/test/scala/cats/tests/CsvCodecInvariantMonoidalTests.scala

@@ -4,7 +4,7 @@ package tests
 import cats.laws.discipline.eq.catsLawsEqForFn1
 import cats.laws.discipline.{InvariantMonoidalTests, SerializableTests}
 import cats.instances.all._
-import cats.syntax.cartesian._
+import cats.syntax.apply._
 import cats.Eq
 import org.scalacheck.{Arbitrary, Gen}
 
@@ -42,7 +42,7 @@ object CsvCodecInvariantMonoidalTests {
           def read(s: CSV): (Option[(A, B)], CSV) = {
             val (a1, s1) = fa.read(s)
             val (a2, s2) = fb.read(s1)
-            ((a1 |@| a2).map(_ -> _), s2)
+            ((a1,  a2).mapN(_ -> _), s2)
           }
 
           def write(a: (A, B)): CSV =

tests/src/test/scala/cats/tests/SyntaxTests.scala

@@ -180,28 +180,37 @@ object SyntaxTests extends AllInstances with AllSyntax {
     val fb1: F[B] = fa.as(b)
   }
 
-  def testApply[F[_]: Apply, A, B, C, D, Z]: Unit = {
+  def testApply[F[_]: Apply : Cartesian, G[_]: Contravariant : Cartesian, H[_]: Invariant : Cartesian, A, B, C, D, E, Z] = {
+    val tfabc = mock[(F[A], F[B], F[C])]
     val fa = mock[F[A]]
-    val fab = mock[F[A => B]]
-    val fb0: F[B] = fab.ap(fa)
-
     val fb = mock[F[B]]
-    val fabz = mock[F[(A, B) => Z]]
-    val fz0: F[Z] = fabz.ap2(fa, fb)
+    val fc = mock[F[C]]
+    val f = mock[(A, B, C) => Z]
+    val ff = mock[F[(A, B, C) => Z]]
+
+    tfabc mapN f
+    (fa, fb, fc) mapN f
+    (fa, fb, fc) apWith ff
 
-    val f = mock[(A, B) => Z]
-    val fz1: F[Z] = fa.map2(fb)(f)
+    val tgabc = mock[(G[A], G[B])]
+    val ga = mock[G[A]]
+    val gb = mock[G[B]]
+    val g = mock[Z => (A, B)]
 
-    val f1 = mock[(A, B) => Z]
-    val ff1 = mock[F[(A, B) => Z]]
-    val fz2: F[Z] = (fa |@| fb).map(f1)
-    val fz3: F[Z] = (fa |@| fb).apWith(ff1)
+    tgabc contramapN g
+    (ga, gb) contramapN g
 
-    val fc = mock[F[C]]
-    val f2 = mock[(A, B, C) => Z]
-    val ff2 = mock[F[(A, B, C) => Z]]
-    val fz4: F[Z] = (fa |@| fb |@| fc).map(f2)
-    val fz5: F[Z] = (fa |@| fb |@| fc).apWith(ff2)
+    val thabcde = mock[(H[A], H[B], H[C], H[D], H[E])]
+    val ha = mock[H[A]]
+    val hb = mock[H[B]]
+    val hc = mock[H[C]]
+    val hd = mock[H[D]]
+    val he = mock[H[E]]
+    val f5 = mock[(A, B, C, D, E) => Z]
+    val g5 = mock[Z => (A, B, C, D, E)]
+
+    thabcde.imapN(f5)(g5)
+    (ha, hb, hc, hd, he).imapN(f5)(g5)
   }
 
   def testBifoldable[F[_, _]: Bifoldable, A, B, C, D: Monoid]: Unit = {
@@ -274,38 +283,6 @@ object SyntaxTests extends AllInstances with AllSyntax {
     val gea4 = ga.recoverWith(pfegea)
   }
 
-  def testTupleArity[F[_]: Apply : Cartesian, G[_]: Contravariant : Cartesian, H[_]: Invariant : Cartesian, A, B, C, D, E, Z] = {
-    val tfabc = mock[(F[A], F[B], F[C])]
-    val fa = mock[F[A]]
-    val fb = mock[F[B]]
-    val fc = mock[F[C]]
-    val f = mock[(A, B, C) => Z]
-    val ff = mock[F[(A, B, C) => Z]]
-
-    tfabc map3 f
-    (fa, fb, fc) map3 f
-    (fa, fb, fc) apWith ff
-
-    val tgabc = mock[(G[A], G[B])]
-    val ga = mock[G[A]]
-    val gb = mock[G[B]]
-    val g = mock[Z => (A, B)]
-
-    tgabc contramap2 g
-    (ga, gb) contramap2 g
-
-    val thabcde = mock[(H[A], H[B], H[C], H[D], H[E])]
-    val ha = mock[H[A]]
-    val hb = mock[H[B]]
-    val hc = mock[H[C]]
-    val hd = mock[H[D]]
-    val he = mock[H[E]]
-    val f5 = mock[(A, B, C, D, E) => Z]
-    val g5 = mock[Z => (A, B, C, D, E)]
-
-    thabcde.imap5(f5)(g5)
-    (ha, hb, hc, hd, he).imap5(f5)(g5)
-  }
 }
 
 /**