fix: introduce stateless iterator

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

lazy/sequence.go

@@ -0,0 +1,39 @@
+// Copyright (c) 2023 IBM Corp.
+// All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package lazy
+
+import (
+	G "github.com/IBM/fp-go/io/generic"
+	T "github.com/IBM/fp-go/tuple"
+)
+
+// SequenceT converts n inputs of higher kinded types into a higher kinded types of n strongly typed values, represented as a tuple
+
+func SequenceT1[A any](a Lazy[A]) Lazy[T.Tuple1[A]] {
+	return G.SequenceT1[Lazy[A], Lazy[T.Tuple1[A]]](a)
+}
+
+func SequenceT2[A, B any](a Lazy[A], b Lazy[B]) Lazy[T.Tuple2[A, B]] {
+	return G.SequenceT2[Lazy[A], Lazy[B], Lazy[T.Tuple2[A, B]]](a, b)
+}
+
+func SequenceT3[A, B, C any](a Lazy[A], b Lazy[B], c Lazy[C]) Lazy[T.Tuple3[A, B, C]] {
+	return G.SequenceT3[Lazy[A], Lazy[B], Lazy[C], Lazy[T.Tuple3[A, B, C]]](a, b, c)
+}
+
+func SequenceT4[A, B, C, D any](a Lazy[A], b Lazy[B], c Lazy[C], d Lazy[D]) Lazy[T.Tuple4[A, B, C, D]] {
+	return G.SequenceT4[Lazy[A], Lazy[B], Lazy[C], Lazy[D], Lazy[T.Tuple4[A, B, C, D]]](a, b, c, d)
+}