Add iteration module

iteration/iteration_test.go

@@ -0,0 +1,22 @@
+package iteration
+
+import "testing"
+
+func TestRepeat(t *testing.T) {
+	got := Repeat("a")
+	want := "aaaaa"
+	assertResult(t, got, want)
+}
+
+func assertResult(t testing.TB, got, want string) {
+	t.Helper()
+	if got != want {
+		t.Errorf("got %q want %q", got, want)
+	}
+}
+
+func BenchmarkRepeat(b *testing.B) {
+	for b.Loop() {
+		Repeat("a")
+	}
+}