fix: traverse

Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com>

v2/array/generic/monoid.go

@@ -0,0 +1,34 @@
+package generic
+
+import (
+	"github.com/IBM/fp-go/v2/internal/array"
+	M "github.com/IBM/fp-go/v2/monoid"
+	S "github.com/IBM/fp-go/v2/semigroup"
+)
+
+// Monoid returns a Monoid instance for arrays.
+// The Monoid combines arrays through concatenation, with an empty array as the identity element.
+//
+// Example:
+//
+//	m := array.Monoid[int]()
+//	result := m.Concat([]int{1, 2}, []int{3, 4}) // [1, 2, 3, 4]
+//	empty := m.Empty() // []
+//
+//go:inline
+func Monoid[GT ~[]T, T any]() M.Monoid[GT] {
+	return M.MakeMonoid(array.Concat[GT], Empty[GT]())
+}
+
+// Semigroup returns a Semigroup instance for arrays.
+// The Semigroup combines arrays through concatenation.
+//
+// Example:
+//
+//	s := array.Semigroup[int]()
+//	result := s.Concat([]int{1, 2}, []int{3, 4}) // [1, 2, 3, 4]
+//
+//go:inline
+func Semigroup[GT ~[]T, T any]() S.Semigroup[GT] {
+	return S.MakeSemigroup(array.Concat[GT])
+}