Use helper constructor for Band and (Bounded)Semilattice instances

Author: joroKr21

algebra-core/src/main/scala/algebra/lattice/BoundedJoinSemilattice.scala

@@ -24,15 +24,12 @@ package lattice
 
 import scala.{specialized => sp}
 
-trait BoundedJoinSemilattice[@sp(Int, Long, Float, Double) A] extends Any with JoinSemilattice[A] { self =>
+trait BoundedJoinSemilattice[@sp(Int, Long, Float, Double) A] extends Any with JoinSemilattice[A] {
   def zero: A
   def isZero(a: A)(implicit ev: Eq[A]): Boolean = ev.eqv(a, zero)
 
   override def joinSemilattice: BoundedSemilattice[A] =
-    new BoundedSemilattice[A] {
-      def empty: A = self.zero
-      def combine(x: A, y: A): A = join(x, y)
-    }
+    BoundedSemilattice.instance(zero, join)
 }
 
 trait BoundedJoinSemilatticeFunctions[B[A] <: BoundedJoinSemilattice[A]] extends JoinSemilatticeFunctions[B] {

algebra-core/src/main/scala/algebra/lattice/BoundedMeetSemilattice.scala

@@ -24,15 +24,12 @@ package lattice
 
 import scala.{specialized => sp}
 
-trait BoundedMeetSemilattice[@sp(Int, Long, Float, Double) A] extends Any with MeetSemilattice[A] { self =>
+trait BoundedMeetSemilattice[@sp(Int, Long, Float, Double) A] extends Any with MeetSemilattice[A] {
   def one: A
   def isOne(a: A)(implicit ev: Eq[A]): Boolean = ev.eqv(a, one)
 
   override def meetSemilattice: BoundedSemilattice[A] =
-    new BoundedSemilattice[A] {
-      def empty: A = self.one
-      def combine(x: A, y: A): A = meet(x, y)
-    }
+    BoundedSemilattice.instance(one, meet)
 }
 
 trait BoundedMeetSemilatticeFunctions[B[A] <: BoundedMeetSemilattice[A]] extends MeetSemilatticeFunctions[B] {

algebra-core/src/main/scala/algebra/lattice/JoinSemilattice.scala

@@ -29,13 +29,11 @@ import scala.{specialized => sp}
  * operation is called "join", and which can be thought of as a least
  * upper bound.
  */
-trait JoinSemilattice[@sp(Int, Long, Float, Double) A] extends Any with Serializable { self =>
+trait JoinSemilattice[@sp(Int, Long, Float, Double) A] extends Any with Serializable {
   def join(lhs: A, rhs: A): A
 
   def joinSemilattice: Semilattice[A] =
-    new Semilattice[A] {
-      def combine(x: A, y: A): A = self.join(x, y)
-    }
+    Semilattice.instance(join)
 
   def joinPartialOrder(implicit ev: Eq[A]): PartialOrder[A] =
     joinSemilattice.asJoinPartialOrder

algebra-core/src/main/scala/algebra/lattice/MeetSemilattice.scala

@@ -29,13 +29,11 @@ import scala.{specialized => sp}
  * operation is called "meet", and which can be thought of as a
  * greatest lower bound.
  */
-trait MeetSemilattice[@sp(Int, Long, Float, Double) A] extends Any with Serializable { self =>
+trait MeetSemilattice[@sp(Int, Long, Float, Double) A] extends Any with Serializable {
   def meet(lhs: A, rhs: A): A
 
   def meetSemilattice: Semilattice[A] =
-    new Semilattice[A] {
-      def combine(x: A, y: A): A = self.meet(x, y)
-    }
+    Semilattice.instance(meet)
 
   def meetPartialOrder(implicit ev: Eq[A]): PartialOrder[A] =
     meetSemilattice.asMeetPartialOrder

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

@@ -369,9 +369,7 @@ sealed abstract private[data] class NonEmptyMapInstances extends NonEmptyMapInst
 
   @deprecated("Use catsDataSemigroupForNonEmptyMap", "2.5.0")
   def catsDataBandForNonEmptyMap[K, A]: Band[NonEmptyMap[K, A]] =
-    new Band[NonEmptyMap[K, A]] {
-      def combine(x: NonEmptyMap[K, A], y: NonEmptyMap[K, A]): NonEmptyMap[K, A] = x ++ y
-    }
+    Band.instance(_ ++ _)
 
   implicit def catsDataSemigroupForNonEmptyMap[K, A: Semigroup]: Semigroup[NonEmptyMap[K, A]] =
     Semigroup.instance { (x, y) =>

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

@@ -430,9 +430,7 @@ sealed abstract private[data] class NonEmptySetInstances extends NonEmptySetInst
     Show.show[NonEmptySet[A]](_.show)
 
   implicit def catsDataSemilatticeForNonEmptySet[A]: Semilattice[NonEmptySet[A]] =
-    new Semilattice[NonEmptySet[A]] {
-      def combine(x: NonEmptySet[A], y: NonEmptySet[A]): NonEmptySet[A] = x | y
-    }
+    Semilattice.instance(_ | _)
 }
 
 sealed abstract private[data] class NonEmptySetInstances0 extends NonEmptySetInstances1 {

kernel-laws/shared/src/test/scala/cats/kernel/laws/LawTests.scala

@@ -424,9 +424,7 @@ class Tests extends TestsConfig with DisciplineSuite {
   // esoteric machinery follows...
 
   implicit lazy val band: Band[(Int, Int)] =
-    new Band[(Int, Int)] {
-      def combine(a: (Int, Int), b: (Int, Int)) = (a._1, b._2)
-    }
+    Band.instance((a, b) => (a._1, b._2))
 
   {
     // In order to check the monoid laws for `Order[N]`, we need

kernel/src/main/scala/cats/kernel/Band.scala

@@ -42,8 +42,6 @@ object Band extends SemigroupFunctions[Band] {
   /**
    * Create a `Band` instance from the given function.
    */
-  @inline def instance[A](cmb: (A, A) => A): Band[A] =
-    new Band[A] {
-      override def combine(x: A, y: A): A = cmb(x, y)
-    }
+  @inline def instance[@sp(Int, Long, Float, Double) A](cmb: (A, A) => A): Band[A] =
+    cmb(_, _)
 }

kernel/src/main/scala/cats/kernel/BoundedSemilattice.scala

@@ -41,10 +41,9 @@ object BoundedSemilattice extends SemilatticeFunctions[BoundedSemilattice] {
   /**
    * Create a `BoundedSemilattice` instance from the given function and empty value.
    */
-  @inline def instance[A](emptyValue: A, cmb: (A, A) => A): BoundedSemilattice[A] =
+  @inline def instance[@sp(Int, Long, Float, Double) A](emptyValue: A, cmb: (A, A) => A): BoundedSemilattice[A] =
     new BoundedSemilattice[A] {
       override val empty: A = emptyValue
-
       override def combine(x: A, y: A): A = cmb(x, y)
     }
 }

kernel/src/main/scala/cats/kernel/Semilattice.scala

@@ -89,8 +89,6 @@ object Semilattice extends SemilatticeFunctions[Semilattice] {
   /**
    * Create a `Semilattice` instance from the given function.
    */
-  @inline def instance[A](cmb: (A, A) => A): Semilattice[A] =
-    new Semilattice[A] {
-      override def combine(x: A, y: A): A = cmb(x, y)
-    }
+  @inline def instance[@sp(Int, Long, Float, Double) A](cmb: (A, A) => A): Semilattice[A] =
+    cmb(_, _)
 }