initial checkin

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

semigroup/semigroup_test.go

@@ -0,0 +1,21 @@
+package semigroup
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFirst(t *testing.T) {
+
+	first := First[int]()
+
+	assert.Equal(t, 1, first.Concat(1, 2))
+}
+
+func TestLast(t *testing.T) {
+
+	last := Last[int]()
+
+	assert.Equal(t, 2, last.Concat(1, 2))
+}