fix: correct sequence order of TraverseArraySeq for IO

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

io/generic/ap.go

@@ -27,16 +27,11 @@ const (
 
 // MonadApSeq implements the applicative on a single thread by first executing mab and the ma
 func MonadApSeq[GA ~func() A, GB ~func() B, GAB ~func() func(A) B, A, B any](mab GAB, ma GA) GB {
-	return MakeIO[GB](func() B {
+	return MonadChain(mab, F.Bind1st(MonadMap[GA, GB], ma))
-		return F.Pipe1(
-			ma(),
-			mab(),
-		)
-	})
 }
 
 // MonadApPar implements the applicative on two threads, the main thread executes mab and the actuall
-// apply operation and the second thred computes ma. Communication between the threads happens via a channel
+// apply operation and the second thread computes ma. Communication between the threads happens via a channel
 func MonadApPar[GA ~func() A, GB ~func() B, GAB ~func() func(A) B, A, B any](mab GAB, ma GA) GB {
 	return MakeIO[GB](func() B {
 		c := make(chan A)

io/generic/traverse.go

@@ -32,6 +32,28 @@ func MonadTraverseArray[GB ~func() B, GBS ~func() BBS, AAS ~[]A, BBS ~[]B, A, B
 	)
 }
 
+func MonadTraverseArraySeq[GB ~func() B, GBS ~func() BBS, AAS ~[]A, BBS ~[]B, A, B any](tas AAS, f func(A) GB) GBS {
+	return RA.MonadTraverse(
+		Of[GBS, BBS],
+		Map[GBS, func() func(B) BBS, BBS, func(B) BBS],
+		ApSeq[GBS, func() func(B) BBS, GB],
+
+		tas,
+		f,
+	)
+}
+
+func MonadTraverseArrayPar[GB ~func() B, GBS ~func() BBS, AAS ~[]A, BBS ~[]B, A, B any](tas AAS, f func(A) GB) GBS {
+	return RA.MonadTraverse(
+		Of[GBS, BBS],
+		Map[GBS, func() func(B) BBS, BBS, func(B) BBS],
+		ApPar[GBS, func() func(B) BBS, GB],
+
+		tas,
+		f,
+	)
+}
+
 func TraverseArray[GB ~func() B, GBS ~func() BBS, AAS ~[]A, BBS ~[]B, A, B any](f func(A) GB) func(AAS) GBS {
 	return RA.Traverse[AAS](
 		Of[GBS, BBS],
@@ -42,6 +64,26 @@ func TraverseArray[GB ~func() B, GBS ~func() BBS, AAS ~[]A, BBS ~[]B, A, B any](
 	)
 }
 
+func TraverseArraySeq[GB ~func() B, GBS ~func() BBS, AAS ~[]A, BBS ~[]B, A, B any](f func(A) GB) func(AAS) GBS {
+	return RA.Traverse[AAS](
+		Of[GBS, BBS],
+		Map[GBS, func() func(B) BBS, BBS, func(B) BBS],
+		ApSeq[GBS, func() func(B) BBS, GB],
+
+		f,
+	)
+}
+
+func TraverseArrayPar[GB ~func() B, GBS ~func() BBS, AAS ~[]A, BBS ~[]B, A, B any](f func(A) GB) func(AAS) GBS {
+	return RA.Traverse[AAS](
+		Of[GBS, BBS],
+		Map[GBS, func() func(B) BBS, BBS, func(B) BBS],
+		ApPar[GBS, func() func(B) BBS, GB],
+
+		f,
+	)
+}
+
 func TraverseArrayWithIndex[GB ~func() B, GBS ~func() BBS, AAS ~[]A, BBS ~[]B, A, B any](f func(int, A) GB) func(AAS) GBS {
 	return RA.TraverseWithIndex[AAS](
 		Of[GBS, BBS],
@@ -52,10 +94,38 @@ func TraverseArrayWithIndex[GB ~func() B, GBS ~func() BBS, AAS ~[]A, BBS ~[]B, A
 	)
 }
 
+func TraverseArrayWithIndexSeq[GB ~func() B, GBS ~func() BBS, AAS ~[]A, BBS ~[]B, A, B any](f func(int, A) GB) func(AAS) GBS {
+	return RA.TraverseWithIndex[AAS](
+		Of[GBS, BBS],
+		Map[GBS, func() func(B) BBS, BBS, func(B) BBS],
+		ApSeq[GBS, func() func(B) BBS, GB],
+
+		f,
+	)
+}
+
+func TraverseArrayWithIndexPar[GB ~func() B, GBS ~func() BBS, AAS ~[]A, BBS ~[]B, A, B any](f func(int, A) GB) func(AAS) GBS {
+	return RA.TraverseWithIndex[AAS](
+		Of[GBS, BBS],
+		Map[GBS, func() func(B) BBS, BBS, func(B) BBS],
+		ApPar[GBS, func() func(B) BBS, GB],
+
+		f,
+	)
+}
+
 func SequenceArray[GA ~func() A, GAS ~func() AAS, AAS ~[]A, GAAS ~[]GA, A any](tas GAAS) GAS {
 	return MonadTraverseArray[GA, GAS](tas, F.Identity[GA])
 }
 
+func SequenceArraySeq[GA ~func() A, GAS ~func() AAS, AAS ~[]A, GAAS ~[]GA, A any](tas GAAS) GAS {
+	return MonadTraverseArraySeq[GA, GAS](tas, F.Identity[GA])
+}
+
+func SequenceArrayPar[GA ~func() A, GAS ~func() AAS, AAS ~[]A, GAAS ~[]GA, A any](tas GAAS) GAS {
+	return MonadTraverseArrayPar[GA, GAS](tas, F.Identity[GA])
+}
+
 // MonadTraverseRecord transforms a record using an IO transform an IO of a record
 func MonadTraverseRecord[GBS ~func() MB, MA ~map[K]A, GB ~func() B, MB ~map[K]B, K comparable, A, B any](ma MA, f func(A) GB) GBS {
 	return RR.MonadTraverse[MA](
@@ -89,3 +159,71 @@ func TraverseRecordWithIndex[GB ~func() B, GBS ~func() MB, MA ~map[K]A, MB ~map[
 func SequenceRecord[GA ~func() A, GAS ~func() AAS, AAS ~map[K]A, GAAS ~map[K]GA, K comparable, A any](tas GAAS) GAS {
 	return MonadTraverseRecord[GAS](tas, F.Identity[GA])
 }
+
+// MonadTraverseRecordSeq transforms a record using an IO transform an IO of a record
+func MonadTraverseRecordSeq[GBS ~func() MB, MA ~map[K]A, GB ~func() B, MB ~map[K]B, K comparable, A, B any](ma MA, f func(A) GB) GBS {
+	return RR.MonadTraverse[MA](
+		Of[GBS, MB],
+		Map[GBS, func() func(B) MB, MB, func(B) MB],
+		ApSeq[GBS, func() func(B) MB, GB],
+		ma, f,
+	)
+}
+
+// TraverseRecordSeq transforms a record using an IO transform an IO of a record
+func TraverseRecordSeq[GBS ~func() MB, MA ~map[K]A, GB ~func() B, MB ~map[K]B, K comparable, A, B any](f func(A) GB) func(MA) GBS {
+	return RR.Traverse[MA](
+		Of[GBS, MB],
+		Map[GBS, func() func(B) MB, MB, func(B) MB],
+		ApSeq[GBS, func() func(B) MB, GB],
+		f,
+	)
+}
+
+// TraverseRecordWithIndexSeq transforms a record using an IO transform an IO of a record
+func TraverseRecordWithIndexSeq[GB ~func() B, GBS ~func() MB, MA ~map[K]A, MB ~map[K]B, K comparable, A, B any](f func(K, A) GB) func(MA) GBS {
+	return RR.TraverseWithIndex[MA](
+		Of[GBS, MB],
+		Map[GBS, func() func(B) MB, MB, func(B) MB],
+		ApSeq[GBS, func() func(B) MB, GB],
+		f,
+	)
+}
+
+func SequenceRecordSeq[GA ~func() A, GAS ~func() AAS, AAS ~map[K]A, GAAS ~map[K]GA, K comparable, A any](tas GAAS) GAS {
+	return MonadTraverseRecordSeq[GAS](tas, F.Identity[GA])
+}
+
+// MonadTraverseRecordPar transforms a record using an IO transform an IO of a record
+func MonadTraverseRecordPar[GBS ~func() MB, MA ~map[K]A, GB ~func() B, MB ~map[K]B, K comparable, A, B any](ma MA, f func(A) GB) GBS {
+	return RR.MonadTraverse[MA](
+		Of[GBS, MB],
+		Map[GBS, func() func(B) MB, MB, func(B) MB],
+		ApPar[GBS, func() func(B) MB, GB],
+		ma, f,
+	)
+}
+
+// TraverseRecordPar transforms a record using an IO transform an IO of a record
+func TraverseRecordPar[GBS ~func() MB, MA ~map[K]A, GB ~func() B, MB ~map[K]B, K comparable, A, B any](f func(A) GB) func(MA) GBS {
+	return RR.Traverse[MA](
+		Of[GBS, MB],
+		Map[GBS, func() func(B) MB, MB, func(B) MB],
+		ApPar[GBS, func() func(B) MB, GB],
+		f,
+	)
+}
+
+// TraverseRecordWithIndexPar transforms a record using an IO transform an IO of a record
+func TraverseRecordWithIndexPar[GB ~func() B, GBS ~func() MB, MA ~map[K]A, MB ~map[K]B, K comparable, A, B any](f func(K, A) GB) func(MA) GBS {
+	return RR.TraverseWithIndex[MA](
+		Of[GBS, MB],
+		Map[GBS, func() func(B) MB, MB, func(B) MB],
+		ApPar[GBS, func() func(B) MB, GB],
+		f,
+	)
+}
+
+func SequenceRecordPar[GA ~func() A, GAS ~func() AAS, AAS ~map[K]A, GAAS ~map[K]GA, K comparable, A any](tas GAAS) GAS {
+	return MonadTraverseRecordPar[GAS](tas, F.Identity[GA])
+}

io/sequence_test.go

@@ -0,0 +1,47 @@
+// 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 io
+
+import (
+	A "github.com/IBM/fp-go/array"
+	F "github.com/IBM/fp-go/function"
+	"github.com/stretchr/testify/assert"
+
+	"testing"
+)
+
+func TestMapSeq(t *testing.T) {
+	var results []string
+
+	handler := func(value string) IO[string] {
+		return func() string {
+			results = append(results, value)
+			return value
+		}
+	}
+
+	src := A.From("a", "b", "c")
+
+	res := F.Pipe2(
+		src,
+		TraverseArraySeq(handler),
+		Map(func(data []string) bool {
+			return assert.Equal(t, data, results)
+		}),
+	)
+
+	assert.True(t, res())
+}

io/traverse.go

@@ -60,3 +60,45 @@ func TraverseRecordWithIndex[K comparable, A, B any](f func(K, A) IO[B]) func(ma
 func SequenceRecord[K comparable, A any](tas map[K]IO[A]) IO[map[K]A] {
 	return G.SequenceRecord[IO[A], IO[map[K]A]](tas)
 }
+
+func MonadTraverseArraySeq[A, B any](tas []A, f func(A) IO[B]) IO[[]B] {
+	return G.MonadTraverseArraySeq[IO[B], IO[[]B]](tas, f)
+}
+
+// TraverseArraySeq applies a function returning an [IO] to all elements in an array and the
+// transforms this into an [IO] of that array
+func TraverseArraySeq[A, B any](f func(A) IO[B]) func([]A) IO[[]B] {
+	return G.TraverseArraySeq[IO[B], IO[[]B], []A](f)
+}
+
+// TraverseArrayWithIndexSeq applies a function returning an [IO] to all elements in an array and the
+// transforms this into an [IO] of that array
+func TraverseArrayWithIndexSeq[A, B any](f func(int, A) IO[B]) func([]A) IO[[]B] {
+	return G.TraverseArrayWithIndexSeq[IO[B], IO[[]B], []A](f)
+}
+
+// SequenceArraySeq converts an array of [IO] to an [IO] of an array
+func SequenceArraySeq[A any](tas []IO[A]) IO[[]A] {
+	return G.SequenceArraySeq[IO[A], IO[[]A]](tas)
+}
+
+func MonadTraverseRecordSeq[K comparable, A, B any](tas map[K]A, f func(A) IO[B]) IO[map[K]B] {
+	return G.MonadTraverseRecordSeq[IO[map[K]B]](tas, f)
+}
+
+// TraverseRecord applies a function returning an [IO] to all elements in a record and the
+// transforms this into an [IO] of that record
+func TraverseRecordSeq[K comparable, A, B any](f func(A) IO[B]) func(map[K]A) IO[map[K]B] {
+	return G.TraverseRecordSeq[IO[map[K]B], map[K]A, IO[B]](f)
+}
+
+// TraverseRecordWithIndexSeq applies a function returning an [IO] to all elements in a record and the
+// transforms this into an [IO] of that record
+func TraverseRecordWithIndeSeq[K comparable, A, B any](f func(K, A) IO[B]) func(map[K]A) IO[map[K]B] {
+	return G.TraverseRecordWithIndexSeq[IO[B], IO[map[K]B], map[K]A](f)
+}
+
+// SequenceRecordSeq converts a record of [IO] to an [IO] of a record
+func SequenceRecordSeq[K comparable, A any](tas map[K]IO[A]) IO[map[K]A] {
+	return G.SequenceRecordSeq[IO[A], IO[map[K]A]](tas)
+}

ioeither/sequence_test.go

@@ -0,0 +1,48 @@
+// 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 ioeither
+
+import (
+	A "github.com/IBM/fp-go/array"
+	E "github.com/IBM/fp-go/either"
+	F "github.com/IBM/fp-go/function"
+	"github.com/stretchr/testify/assert"
+
+	"testing"
+)
+
+func TestMapSeq(t *testing.T) {
+	var results []string
+
+	handler := func(value string) IOEither[error, string] {
+		return func() E.Either[error, string] {
+			results = append(results, value)
+			return E.Of[error](value)
+		}
+	}
+
+	src := A.From("a", "b", "c")
+
+	res := F.Pipe2(
+		src,
+		TraverseArraySeq(handler),
+		Map[error](func(data []string) bool {
+			return assert.Equal(t, data, results)
+		}),
+	)
+
+	assert.Equal(t, E.Of[error](true), res())
+}