Convert Semigroup and CommutativeSemigroup instances to SAM syntax

joroKr21 · joroKr21 · commit bf8ee7f9887c · 2022-08-12T23:38:55.000+03:00
diff --git a/algebra-core/src/main/scala/algebra/ring/Multiplicative.scala b/algebra-core/src/main/scala/algebra/ring/Multiplicative.scala
@@ -26,8 +26,7 @@ import scala.{specialized => sp}
 import scala.annotation.{nowarn, tailrec}
 
 trait MultiplicativeSemigroup[@sp(Int, Long, Float, Double) A] extends Any with Serializable {
-  def multiplicative: Semigroup[A] =
-    Semigroup.instance(times)
+  def multiplicative: Semigroup[A] = times(_, _)
 
   def times(x: A, y: A): A
 
@@ -56,8 +55,7 @@ trait MultiplicativeSemigroup[@sp(Int, Long, Float, Double) A] extends Any with
 }
 
 trait MultiplicativeCommutativeSemigroup[@sp(Int, Long, Float, Double) A] extends Any with MultiplicativeSemigroup[A] {
-  override def multiplicative: CommutativeSemigroup[A] =
-    CommutativeSemigroup.instance(times)
+  override def multiplicative: CommutativeSemigroup[A] = times(_, _)
 }
 
 trait MultiplicativeMonoid[@sp(Int, Long, Float, Double) A] extends Any with MultiplicativeSemigroup[A] {
diff --git a/core/src/main/scala/cats/Align.scala b/core/src/main/scala/cats/Align.scala
@@ -135,7 +135,7 @@ trait Align[F[_]] extends Serializable {
 
 object Align extends ScalaVersionSpecificAlignInstances {
   def semigroup[F[_], A](implicit F: Align[F], A: Semigroup[A]): Semigroup[F[A]] =
-    Semigroup.instance(F.alignCombine[A])
+    F.alignCombine(_, _)
 
   implicit def catsAlignForList: Align[List] = cats.instances.list.catsStdInstancesForList
   implicit def catsAlignForOption: Align[Option] = cats.instances.option.catsStdInstancesForOption
diff --git a/core/src/main/scala/cats/CommutativeApply.scala b/core/src/main/scala/cats/CommutativeApply.scala
@@ -36,7 +36,7 @@ trait CommutativeApply[F[_]] extends Apply[F]
 
 object CommutativeApply {
   def commutativeSemigroupFor[F[_]: CommutativeApply, A: CommutativeSemigroup]: CommutativeSemigroup[F[A]] =
-    CommutativeSemigroup.instance(CommutativeApply[F].map2(_, _)(CommutativeSemigroup[A].combine))
+    CommutativeApply[F].map2(_, _)(CommutativeSemigroup[A].combine)
 
   /**
    * Summon an instance of [[CommutativeApply]] for `F`.
diff --git a/core/src/main/scala/cats/SemigroupK.scala b/core/src/main/scala/cats/SemigroupK.scala
@@ -86,16 +86,15 @@ trait SemigroupK[F[_]] extends Serializable { self =>
     y.map(yy => combineK(x, yy))
 
   /**
-   * Given a type A, create a concrete Semigroup[F[A]].
+   * Given a type A, create a concrete `Semigroup[F[A]]`.
    *
    * Example:
    * {{{
    * scala> import cats.implicits._
    * scala> val s: Semigroup[List[Int]] = SemigroupK[List].algebra[Int]
    * }}}
    */
-  def algebra[A]: Semigroup[F[A]] =
-    Semigroup.instance(combineK)
+  def algebra[A]: Semigroup[F[A]] = combineK(_, _)
 
   /**
    * "Compose" with a `G[_]` type to form a `SemigroupK` for `λ[α => F[G[α]]]`.
diff --git a/core/src/main/scala/cats/arrow/Compose.scala b/core/src/main/scala/cats/arrow/Compose.scala
@@ -49,8 +49,7 @@ trait Compose[F[_, _]] extends Serializable { self =>
       def combineK[A](f1: F[A, A], f2: F[A, A]): F[A, A] = self.compose(f1, f2)
     }
 
-  def algebra[A]: Semigroup[F[A, A]] =
-    Semigroup.instance(compose)
+  def algebra[A]: Semigroup[F[A, A]] = compose(_, _)
 }
 
 object Compose {
diff --git a/core/src/main/scala/cats/data/Const.scala b/core/src/main/scala/cats/data/Const.scala
@@ -188,8 +188,7 @@ sealed abstract private[data] class ConstInstances1 extends ConstInstances2 {
 
 sealed abstract private[data] class ConstInstances2 extends ConstInstances3 {
 
-  implicit def catsDataSemigroupForConst[A: Semigroup, B]: Semigroup[Const[A, B]] =
-    Semigroup.instance(_ combine _)
+  implicit def catsDataSemigroupForConst[A: Semigroup, B]: Semigroup[Const[A, B]] = _ combine _
 
   implicit def catsDataPartialOrderForConst[A: PartialOrder, B]: PartialOrder[Const[A, B]] = _ partialCompare _
 
diff --git a/core/src/main/scala/cats/data/Ior.scala b/core/src/main/scala/cats/data/Ior.scala
@@ -861,8 +861,7 @@ sealed abstract private[data] class IorInstances extends IorInstances0 {
 
   implicit def catsDataShowForIor[A: Show, B: Show]: Show[A Ior B] = _.show
 
-  implicit def catsDataSemigroupForIor[A: Semigroup, B: Semigroup]: Semigroup[Ior[A, B]] =
-    Semigroup.instance(_ combine _)
+  implicit def catsDataSemigroupForIor[A: Semigroup, B: Semigroup]: Semigroup[Ior[A, B]] = _ combine _
 
   implicit def catsDataMonadErrorForIor[A: Semigroup]: MonadError[Ior[A, *], A] =
     new MonadError[Ior[A, *], A] {
diff --git a/core/src/main/scala/cats/data/NonEmptyMapImpl.scala b/core/src/main/scala/cats/data/NonEmptyMapImpl.scala
@@ -371,9 +371,7 @@ sealed abstract private[data] class NonEmptyMapInstances extends NonEmptyMapInst
     Band.instance(_ ++ _)
 
   implicit def catsDataSemigroupForNonEmptyMap[K, A: Semigroup]: Semigroup[NonEmptyMap[K, A]] =
-    Semigroup.instance { (x, y) =>
-      NonEmptyMap.fromMapUnsafe(Semigroup[SortedMap[K, A]].combine(x.toSortedMap, y.toSortedMap))
-    }
+    (x, y) => NonEmptyMap.fromMapUnsafe(Semigroup[SortedMap[K, A]].combine(x.toSortedMap, y.toSortedMap))
 }
 
 sealed abstract private[data] class NonEmptyMapInstances0 {
diff --git a/core/src/main/scala/cats/data/Validated.scala b/core/src/main/scala/cats/data/Validated.scala
@@ -974,11 +974,7 @@ sealed abstract private[data] class ValidatedInstances extends ValidatedInstance
 
 sealed abstract private[data] class ValidatedInstances1 extends ValidatedInstances2 {
 
-  implicit def catsDataSemigroupForValidated[A, B](implicit
-    A: Semigroup[A],
-    B: Semigroup[B]
-  ): Semigroup[Validated[A, B]] =
-    Semigroup.instance(_ combine _)
+  implicit def catsDataSemigroupForValidated[A: Semigroup, B: Semigroup]: Semigroup[Validated[A, B]] = _ combine _
 
   implicit def catsDataCommutativeApplicativeForValidated[E: CommutativeSemigroup]
     : CommutativeApplicative[Validated[E, *]] =
diff --git a/core/src/main/scala/cats/instances/invariant.scala b/core/src/main/scala/cats/instances/invariant.scala
@@ -45,21 +45,21 @@ trait InvariantMonoidalInstances {
 
   implicit val catsInvariantMonoidalSemigroup: InvariantMonoidal[Semigroup] = new InvariantMonoidal[Semigroup] {
     def product[A, B](fa: Semigroup[A], fb: Semigroup[B]): Semigroup[(A, B)] =
-      Semigroup.instance((x, y) => fa.combine(x._1, y._1) -> fb.combine(x._2, y._2))
+      (x, y) => fa.combine(x._1, y._1) -> fb.combine(x._2, y._2)
 
     def imap[A, B](fa: Semigroup[A])(f: A => B)(g: B => A): Semigroup[B] =
-      Semigroup.instance((x, y) => f(fa.combine(g(x), g(y))))
+      (x, y) => f(fa.combine(g(x), g(y)))
 
     def unit: Semigroup[Unit] = implicitly
   }
 
   implicit val catsInvariantMonoidalCommutativeSemigroup: InvariantMonoidal[CommutativeSemigroup] =
     new InvariantMonoidal[CommutativeSemigroup] {
       def product[A, B](fa: CommutativeSemigroup[A], fb: CommutativeSemigroup[B]): CommutativeSemigroup[(A, B)] =
-        CommutativeSemigroup.instance((x, y) => fa.combine(x._1, y._1) -> fb.combine(x._2, y._2))
+        (x, y) => fa.combine(x._1, y._1) -> fb.combine(x._2, y._2)
 
       def imap[A, B](fa: CommutativeSemigroup[A])(f: A => B)(g: B => A): CommutativeSemigroup[B] =
-        CommutativeSemigroup.instance((x, y) => f(fa.combine(g(x), g(y))))
+        (x, y) => f(fa.combine(g(x), g(y)))
 
       def unit: CommutativeSemigroup[Unit] = implicitly
     }
diff --git a/docs/typeclasses/invariantmonoidal.md b/docs/typeclasses/invariantmonoidal.md
@@ -23,13 +23,11 @@ To construct a `Semigroup` from a single value, we can define a trivial `Semigro
 ```scala mdoc:silent
 import cats.Semigroup
 
-def unit: Semigroup[Unit] =
-  Semigroup.instance((_, _) => ())
+def unit: Semigroup[Unit] = (_, _) => ()
 
-def product[A, B](fa: Semigroup[A], fb: Semigroup[B]): Semigroup[(A, B)] =
-  Semigroup.instance { case ((xa, xb), (ya, yb)) =>
-    fa.combine(xa, ya) -> fb.combine(xb, yb)
-  }
+def product[A, B](fa: Semigroup[A], fb: Semigroup[B]): Semigroup[(A, B)] = {
+  case ((xa, xb), (ya, yb)) => fa.combine(xa, ya) -> fb.combine(xb, yb)
+}
 ```
 
 Given an instance of `InvariantMonoidal` for `Semigroup`, we are able to combine existing `Semigroup` instances to form a new `Semigroup` by using the `Semigroupal` syntax:
diff --git a/docs/typeclasses/monoid.md b/docs/typeclasses/monoid.md
@@ -82,8 +82,7 @@ final case class NonEmptyList[A](head: A, tail: List[A]) {
 }
 
 object NonEmptyList {
-  implicit def nonEmptyListSemigroup[A]: Semigroup[NonEmptyList[A]] =
-    Semigroup.instance(_ ++ _)
+  implicit def nonEmptyListSemigroup[A]: Semigroup[NonEmptyList[A]] = _ ++ _
 }
 ```
 
diff --git a/docs/typeclasses/semigroup.md b/docs/typeclasses/semigroup.md
@@ -20,8 +20,7 @@ A common example of a semigroup is the type `Int` with the operation `+`.
 ```scala mdoc:reset:silent
 import cats.Semigroup
 
-implicit val intAdditionSemigroup: Semigroup[Int] =
-  Semigroup.instance(_ + _)
+implicit val intAdditionSemigroup: Semigroup[Int] = _ + _
 
 val x = 1
 val y = 2
diff --git a/kernel/src/main/scala/cats/kernel/CommutativeSemigroup.scala b/kernel/src/main/scala/cats/kernel/CommutativeSemigroup.scala
@@ -54,6 +54,5 @@ object CommutativeSemigroup extends SemigroupFunctions[CommutativeSemigroup] {
   /**
    * Create a `CommutativeSemigroup` instance from the given function.
    */
-  @inline def instance[@sp(Int, Long, Float, Double) A](cmb: (A, A) => A): CommutativeSemigroup[A] =
-    cmb(_, _)
+  @inline def instance[A](cmb: (A, A) => A): CommutativeSemigroup[A] = cmb(_, _)
 }
diff --git a/kernel/src/main/scala/cats/kernel/Semigroup.scala b/kernel/src/main/scala/cats/kernel/Semigroup.scala
@@ -21,8 +21,6 @@
 
 package cats.kernel
 
-import cats.kernel.Semigroup.instance
-
 import scala.annotation.tailrec
 import scala.collection.immutable.{BitSet, Queue, Seq, SortedMap, SortedSet}
 import scala.concurrent.{ExecutionContext, Future}
@@ -122,7 +120,7 @@ trait Semigroup[@sp(Int, Long, Float, Double) A] extends Any with Serializable {
    * This name matches the term used in Foldable and Reducible and a similar Haskell function.
    */
   def intercalate(middle: A): Semigroup[A] =
-    instance((a, b) => self.combine(a, self.combine(middle, b)))
+    (a, b) => self.combine(a, self.combine(middle, b))
 }
 
 abstract class SemigroupFunctions[S[T] <: Semigroup[T]] {
@@ -168,20 +166,17 @@ object Semigroup
   /**
    * Create a `Semigroup` instance from the given function.
    */
-  @inline def instance[@sp(Int, Long, Float, Double) A](cmb: (A, A) => A): Semigroup[A] =
-    cmb(_, _)
+  @inline def instance[A](cmb: (A, A) => A): Semigroup[A] = cmb(_, _)
 
   /**
    * Create a `Semigroup` instance that always returns the lefthand side.
    */
-  @inline def first[A]: Semigroup[A] =
-    instance((x, _) => x)
+  @inline def first[A]: Semigroup[A] = (x, _) => x
 
   /**
    * Create a `Semigroup` instance that always returns the righthand side.
    */
-  @inline def last[A]: Semigroup[A] =
-    instance((_, y) => y)
+  @inline def last[A]: Semigroup[A] = (_, y) => y
 
   implicit def catsKernelBoundedSemilatticeForBitSet: BoundedSemilattice[BitSet] =
     cats.kernel.instances.bitSet.catsKernelStdSemilatticeForBitSet
diff --git a/kernel/src/main/scala/cats/kernel/instances/EitherInstances.scala b/kernel/src/main/scala/cats/kernel/instances/EitherInstances.scala
@@ -60,7 +60,7 @@ trait EitherInstances extends EitherInstances0 {
 private[instances] trait EitherInstances0 extends EitherInstances1 {
 
   implicit def catsDataSemigroupForEither[A, B](implicit B: Semigroup[B]): Semigroup[Either[A, B]] =
-    Semigroup.instance { (x, y) =>
+    (x, y) =>
       x match {
         case left @ Left(_) => left
         case Right(xx) =>
@@ -69,7 +69,6 @@ private[instances] trait EitherInstances0 extends EitherInstances1 {
             case Right(yy)      => Right(B.combine(xx, yy))
           }
       }
-    }
 
   implicit def catsStdPartialOrderForEither[A, B](implicit
     A: PartialOrder[A],

Original file line number	Diff line number	Diff line change
`@@ -26,8 +26,7 @@ import scala.{specialized => sp}`
`26`	`26`	`import scala.annotation.{nowarn, tailrec}`
`27`	`27`
`28`	`28`	`trait MultiplicativeSemigroup[@sp(Int, Long, Float, Double) A] extends Any with Serializable {`
`29`		`- def multiplicative: Semigroup[A] =`
`30`		`- Semigroup.instance(times)`
	`29`	`+ def multiplicative: Semigroup[A] = times(_, _)`
`31`	`30`
`32`	`31`	`def times(x: A, y: A): A`
`33`	`32`
`@@ -56,8 +55,7 @@ trait MultiplicativeSemigroup[@sp(Int, Long, Float, Double) A] extends Any with`
`56`	`55`	`}`
`57`	`56`
`58`	`57`	`trait MultiplicativeCommutativeSemigroup[@sp(Int, Long, Float, Double) A] extends Any with MultiplicativeSemigroup[A] {`
`59`		`- override def multiplicative: CommutativeSemigroup[A] =`
`60`		`- CommutativeSemigroup.instance(times)`
	`58`	`+ override def multiplicative: CommutativeSemigroup[A] = times(_, _)`
`61`	`59`	`}`
`62`	`60`
`63`	`61`	`trait MultiplicativeMonoid[@sp(Int, Long, Float, Double) A] extends Any with MultiplicativeSemigroup[A] {`
Original file line number	Diff line number	Diff line change
`@@ -49,8 +49,7 @@ trait Compose[F[_, _]] extends Serializable { self =>`
`49`	`49`	`def combineK[A](f1: F[A, A], f2: F[A, A]): F[A, A] = self.compose(f1, f2)`
`50`	`50`	`}`
`51`	`51`
`52`		`- def algebra[A]: Semigroup[F[A, A]] =`
`53`		`- Semigroup.instance(compose)`
	`52`	`+ def algebra[A]: Semigroup[F[A, A]] = compose(_, _)`
`54`	`53`	`}`
`55`	`54`
`56`	`55`	`object Compose {`
Original file line number	Diff line number	Diff line change
`@@ -371,9 +371,7 @@ sealed abstract private[data] class NonEmptyMapInstances extends NonEmptyMapInst`
`371`	`371`	`Band.instance(_ ++ _)`
`372`	`372`
`373`	`373`	`implicit def catsDataSemigroupForNonEmptyMap[K, A: Semigroup]: Semigroup[NonEmptyMap[K, A]] =`
`374`		`- Semigroup.instance { (x, y) =>`
`375`		`- NonEmptyMap.fromMapUnsafe(Semigroup[SortedMap[K, A]].combine(x.toSortedMap, y.toSortedMap))`
`376`		`- }`
	`374`	`+ (x, y) => NonEmptyMap.fromMapUnsafe(Semigroup[SortedMap[K, A]].combine(x.toSortedMap, y.toSortedMap))`
`377`	`375`	`}`
`378`	`376`
`379`	`377`	`sealed abstract private[data] class NonEmptyMapInstances0 {`