Merge pull request #42 from IBM/cleue-add-traverse-with-index

fix: add missing withIndex methods

context/reader/array.go

@@ -24,6 +24,11 @@ func TraverseArray[A, B any](f func(A) Reader[B]) func([]A) Reader[[]B] {
 	return R.TraverseArray[Reader[B], Reader[[]B], []A](f)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[A, B any](f func(int, A) Reader[B]) func([]A) Reader[[]B] {
+	return R.TraverseArrayWithIndex[Reader[B], Reader[[]B], []A](f)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[A any](ma []Reader[A]) Reader[[]A] {
 	return R.SequenceArray[Reader[A], Reader[[]A]](ma)

context/readereither/array.go

@@ -24,6 +24,11 @@ func TraverseArray[A, B any](f func(A) ReaderEither[B]) func([]A) ReaderEither[[
 	return RE.TraverseArray[ReaderEither[B], ReaderEither[[]B], []A](f)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[A, B any](f func(int, A) ReaderEither[B]) func([]A) ReaderEither[[]B] {
+	return RE.TraverseArrayWithIndex[ReaderEither[B], ReaderEither[[]B], []A](f)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[A any](ma []ReaderEither[A]) ReaderEither[[]A] {
 	return RE.SequenceArray[ReaderEither[A], ReaderEither[[]A]](ma)

context/readerio/array.go

@@ -25,6 +25,11 @@ func TraverseArray[A, B any](f func(A) ReaderIO[B]) func([]A) ReaderIO[[]B] {
 	return R.TraverseArray[ReaderIO[B], ReaderIO[[]B], IO.IO[B], IO.IO[[]B], []A](f)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[A, B any](f func(int, A) ReaderIO[B]) func([]A) ReaderIO[[]B] {
+	return R.TraverseArrayWithIndex[ReaderIO[B], ReaderIO[[]B], IO.IO[B], IO.IO[[]B], []A](f)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[A any](ma []ReaderIO[A]) ReaderIO[[]A] {
 	return R.SequenceArray[ReaderIO[A], ReaderIO[[]A]](ma)

context/readerioeither/generic/traverse.go

@@ -62,6 +62,25 @@ func TraverseArray[
 	)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[
+	AS ~[]A,
+	GRBS ~func(context.Context) GIOBS,
+	GRB ~func(context.Context) GIOB,
+	GIOBS ~func() E.Either[error, BS],
+	GIOB ~func() E.Either[error, B],
+	BS ~[]B,
+	A, B any](f func(int, A) GRB) func(AS) GRBS {
+
+	return RA.TraverseWithIndex[AS](
+		Of[GRBS, GIOBS, BS],
+		Map[GRBS, func(context.Context) func() E.Either[error, func(B) BS], GIOBS, func() E.Either[error, func(B) BS], BS, func(B) BS],
+		Ap[GRBS, func(context.Context) func() E.Either[error, func(B) BS], GRB],
+
+		f,
+	)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[
 	AS ~[]A,
@@ -115,6 +134,26 @@ func TraverseRecord[K comparable,
 	)
 }
 
+// TraverseRecordWithIndex transforms a record
+func TraverseRecordWithIndex[K comparable,
+	AS ~map[K]A,
+	GRBS ~func(context.Context) GIOBS,
+	GRB ~func(context.Context) GIOB,
+	GIOBS ~func() E.Either[error, BS],
+	GIOB ~func() E.Either[error, B],
+	BS ~map[K]B,
+
+	A, B any](f func(K, A) GRB) func(AS) GRBS {
+
+	return RR.TraverseWithIndex[AS](
+		Of[GRBS, GIOBS, BS],
+		Map[GRBS, func(context.Context) func() E.Either[error, func(B) BS], GIOBS, func() E.Either[error, func(B) BS], BS, func(B) BS],
+		Ap[GRBS, func(context.Context) func() E.Either[error, func(B) BS], GRB],
+
+		f,
+	)
+}
+
 // SequenceRecord converts a homogeneous sequence of either into an either of sequence
 func SequenceRecord[K comparable,
 	AS ~map[K]A,

context/readerioeither/traverse.go

@@ -24,6 +24,11 @@ func TraverseArray[A, B any](f func(A) ReaderIOEither[B]) func([]A) ReaderIOEith
 	return G.TraverseArray[[]A, ReaderIOEither[[]B]](f)
 }
 
+// TraverseArrayWithIndex uses transforms an array [[]A] into [[]ReaderIOEither[B]] and then resolves that into a [ReaderIOEither[[]B]]
+func TraverseArrayWithIndex[A, B any](f func(int, A) ReaderIOEither[B]) func([]A) ReaderIOEither[[]B] {
+	return G.TraverseArrayWithIndex[[]A, ReaderIOEither[[]B]](f)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[A any](ma []ReaderIOEither[A]) ReaderIOEither[[]A] {
 	return G.SequenceArray[[]A, []ReaderIOEither[A], ReaderIOEither[[]A]](ma)
@@ -34,6 +39,11 @@ func TraverseRecord[K comparable, A, B any](f func(A) ReaderIOEither[B]) func(ma
 	return G.TraverseRecord[K, map[K]A, ReaderIOEither[map[K]B]](f)
 }
 
+// TraverseRecordWithIndex uses transforms a record [map[K]A] into [map[K]ReaderIOEither[B]] and then resolves that into a [ReaderIOEither[map[K]B]]
+func TraverseRecordWithIndex[K comparable, A, B any](f func(K, A) ReaderIOEither[B]) func(map[K]A) ReaderIOEither[map[K]B] {
+	return G.TraverseRecordWithIndex[K, map[K]A, ReaderIOEither[map[K]B]](f)
+}
+
 // SequenceRecord converts a homogeneous sequence of either into an either of sequence
 func SequenceRecord[K comparable, A any](ma map[K]ReaderIOEither[A]) ReaderIOEither[map[K]A] {
 	return G.SequenceRecord[K, map[K]A, map[K]ReaderIOEither[A], ReaderIOEither[map[K]A]](ma)

either/array.go

@@ -20,7 +20,7 @@ import (
 	RA "github.com/IBM/fp-go/internal/array"
 )
 
-// TraverseArray transforms an array
+// TraverseArrayG transforms an array
 func TraverseArrayG[GA ~[]A, GB ~[]B, E, A, B any](f func(A) Either[E, B]) func(GA) Either[E, GB] {
 	return RA.Traverse[GA](
 		Of[E, GB],
@@ -36,6 +36,22 @@ func TraverseArray[E, A, B any](f func(A) Either[E, B]) func([]A) Either[E, []B]
 	return TraverseArrayG[[]A, []B](f)
 }
 
+// TraverseArrayWithIndexG transforms an array
+func TraverseArrayWithIndexG[GA ~[]A, GB ~[]B, E, A, B any](f func(int, A) Either[E, B]) func(GA) Either[E, GB] {
+	return RA.TraverseWithIndex[GA](
+		Of[E, GB],
+		Map[E, GB, func(B) GB],
+		Ap[GB, E, B],
+
+		f,
+	)
+}
+
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[E, A, B any](f func(int, A) Either[E, B]) func([]A) Either[E, []B] {
+	return TraverseArrayWithIndexG[[]A, []B](f)
+}
+
 func SequenceArrayG[GA ~[]A, GOA ~[]Either[E, A], E, A any](ma GOA) Either[E, GA] {
 	return TraverseArrayG[GOA, GA](F.Identity[Either[E, A]])(ma)
 }

either/record.go

@@ -20,7 +20,7 @@ import (
 	RR "github.com/IBM/fp-go/internal/record"
 )
 
-// TraverseRecord transforms a record of options into an option of a record
+// TraverseRecordG transforms a record of options into an option of a record
 func TraverseRecordG[GA ~map[K]A, GB ~map[K]B, K comparable, E, A, B any](f func(A) Either[E, B]) func(GA) Either[E, GB] {
 	return RR.Traverse[GA](
 		Of[E, GB],
@@ -35,6 +35,21 @@ func TraverseRecord[K comparable, E, A, B any](f func(A) Either[E, B]) func(map[
 	return TraverseRecordG[map[K]A, map[K]B](f)
 }
 
+// TraverseRecordWithIndexG transforms a record of options into an option of a record
+func TraverseRecordWithIndexG[GA ~map[K]A, GB ~map[K]B, K comparable, E, A, B any](f func(K, A) Either[E, B]) func(GA) Either[E, GB] {
+	return RR.TraverseWithIndex[GA](
+		Of[E, GB],
+		Map[E, GB, func(B) GB],
+		Ap[GB, E, B],
+		f,
+	)
+}
+
+// TraverseRecordWithIndex transforms a record of eithers into an either of a record
+func TraverseRecordWithIndex[K comparable, E, A, B any](f func(K, A) Either[E, B]) func(map[K]A) Either[E, map[K]B] {
+	return TraverseRecordWithIndexG[map[K]A, map[K]B](f)
+}
+
 func SequenceRecordG[GA ~map[K]A, GOA ~map[K]Either[E, A], K comparable, E, A any](ma GOA) Either[E, GA] {
 	return TraverseRecordG[GOA, GA](F.Identity[Either[E, A]])(ma)
 }

internal/array/traverse.go

@@ -37,6 +37,24 @@ func MonadTraverse[GA ~[]A, GB ~[]B, A, B, HKTB, HKTAB, HKTRB any](
 	return MonadTraverseReduce(fof, fmap, fap, ta, f, Append[GB, B], Empty[GB]())
 }
 
+/*
+*
+We need to pass the members of the applicative explicitly, because golang does neither support higher kinded types nor template methods on structs or interfaces
+
+HKTRB = HKT<GB>
+HKTB = HKT<B>
+HKTAB = HKT<func(A)B>
+*/
+func MonadTraverseWithIndex[GA ~[]A, GB ~[]B, A, B, HKTB, HKTAB, HKTRB any](
+	fof func(GB) HKTRB,
+	fmap func(func(GB) func(B) GB) func(HKTRB) HKTAB,
+	fap func(HKTB) func(HKTAB) HKTRB,
+
+	ta GA,
+	f func(int, A) HKTB) HKTRB {
+	return MonadTraverseReduceWithIndex(fof, fmap, fap, ta, f, Append[GB, B], Empty[GB]())
+}
+
 func Traverse[GA ~[]A, GB ~[]B, A, B, HKTB, HKTAB, HKTRB any](
 	fof func(GB) HKTRB,
 	fmap func(func(GB) func(B) GB) func(HKTRB) HKTAB,
@@ -49,6 +67,18 @@ func Traverse[GA ~[]A, GB ~[]B, A, B, HKTB, HKTAB, HKTRB any](
 	}
 }
 
+func TraverseWithIndex[GA ~[]A, GB ~[]B, A, B, HKTB, HKTAB, HKTRB any](
+	fof func(GB) HKTRB,
+	fmap func(func(GB) func(B) GB) func(HKTRB) HKTAB,
+	fap func(HKTB) func(HKTAB) HKTRB,
+
+	f func(int, A) HKTB) func(GA) HKTRB {
+
+	return func(ma GA) HKTRB {
+		return MonadTraverseWithIndex(fof, fmap, fap, ma, f)
+	}
+}
+
 func MonadTraverseReduce[GA ~[]A, GB, A, B, HKTB, HKTAB, HKTRB any](
 	fof func(GB) HKTRB,
 	fmap func(func(GB) func(B) GB) func(HKTRB) HKTAB,
@@ -71,6 +101,28 @@ func MonadTraverseReduce[GA ~[]A, GB, A, B, HKTB, HKTAB, HKTRB any](
 	}, fof(initial))
 }
 
+func MonadTraverseReduceWithIndex[GA ~[]A, GB, A, B, HKTB, HKTAB, HKTRB any](
+	fof func(GB) HKTRB,
+	fmap func(func(GB) func(B) GB) func(HKTRB) HKTAB,
+	fap func(HKTB) func(HKTAB) HKTRB,
+
+	ta GA,
+
+	transform func(int, A) HKTB,
+	reduce func(GB, B) GB,
+	initial GB,
+) HKTRB {
+	mmap := fmap(F.Curry2(reduce))
+
+	return ReduceWithIndex(ta, func(idx int, r HKTRB, a A) HKTRB {
+		return F.Pipe2(
+			r,
+			mmap,
+			fap(transform(idx, a)),
+		)
+	}, fof(initial))
+}
+
 func TraverseReduce[GA ~[]A, GB, A, B, HKTB, HKTAB, HKTRB any](
 	fof func(GB) HKTRB,
 	fmap func(func(GB) func(B) GB) func(HKTRB) HKTAB,
@@ -84,3 +136,17 @@ func TraverseReduce[GA ~[]A, GB, A, B, HKTB, HKTAB, HKTRB any](
 		return MonadTraverseReduce(fof, fmap, fap, ta, transform, reduce, initial)
 	}
 }
+
+func TraverseReduceWithIndex[GA ~[]A, GB, A, B, HKTB, HKTAB, HKTRB any](
+	fof func(GB) HKTRB,
+	fmap func(func(GB) func(B) GB) func(HKTRB) HKTAB,
+	fap func(HKTB) func(HKTAB) HKTRB,
+
+	transform func(int, A) HKTB,
+	reduce func(GB, B) GB,
+	initial GB,
+) func(GA) HKTRB {
+	return func(ta GA) HKTRB {
+		return MonadTraverseReduceWithIndex(fof, fmap, fap, ta, transform, reduce, initial)
+	}
+}

io/generic/traverse.go

@@ -42,6 +42,16 @@ func TraverseArray[GB ~func() B, GBS ~func() BBS, AAS ~[]A, BBS ~[]B, A, B any](
 	)
 }
 
+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],
+		Map[GBS, func() func(B) BBS, BBS, func(B) BBS],
+		Ap[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])
 }
@@ -66,6 +76,16 @@ func TraverseRecord[GB ~func() B, GBS ~func() MB, MA ~map[K]A, MB ~map[K]B, K co
 	)
 }
 
+// TraverseRecordWithIndex transforms a record using an IO transform an IO of a record
+func TraverseRecordWithIndex[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],
+		Ap[GBS, func() func(B) MB, GB],
+		f,
+	)
+}
+
 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[GA, GAS](tas, F.Identity[GA])
 }

io/traverse.go

@@ -29,6 +29,12 @@ func TraverseArray[A, B any](f func(A) IO[B]) func([]A) IO[[]B] {
 	return G.TraverseArray[IO[B], IO[[]B], []A](f)
 }
 
+// TraverseArrayWithIndex applies a function returning an [IO] to all elements in an array and the
+// transforms this into an [IO] of that array
+func TraverseArrayWithIndex[A, B any](f func(int, A) IO[B]) func([]A) IO[[]B] {
+	return G.TraverseArrayWithIndex[IO[B], IO[[]B], []A](f)
+}
+
 // SequenceArray converts an array of [IO] to an [IO] of an array
 func SequenceArray[A any](tas []IO[A]) IO[[]A] {
 	return G.SequenceArray[IO[A], IO[[]A]](tas)
@@ -38,12 +44,18 @@ func MonadTraverseRecord[K comparable, A, B any](tas map[K]A, f func(A) IO[B]) I
 	return G.MonadTraverseRecord[IO[B], IO[map[K]B]](tas, f)
 }
 
-// TraverseArray applies a function returning an [IO] to all elements in a record and the
+// TraverseRecord applies a function returning an [IO] to all elements in a record and the
 // transforms this into an [IO] of that record
 func TraverseRecord[K comparable, A, B any](f func(A) IO[B]) func(map[K]A) IO[map[K]B] {
 	return G.TraverseRecord[IO[B], IO[map[K]B], map[K]A](f)
 }
 
+// TraverseRecordWithIndex applies a function returning an [IO] to all elements in a record and the
+// transforms this into an [IO] of that record
+func TraverseRecordWithIndex[K comparable, A, B any](f func(K, A) IO[B]) func(map[K]A) IO[map[K]B] {
+	return G.TraverseRecordWithIndex[IO[B], IO[map[K]B], map[K]A](f)
+}
+
 // SequenceRecord converts a record of [IO] to an [IO] of a record
 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)

ioeither/generic/traverse.go

@@ -45,6 +45,29 @@ func TraverseArray[GB ~func() ET.Either[E, B], GBS ~func() ET.Either[E, BBS], AA
 	)
 }
 
+// MonadTraverseArrayWithIndex transforms an array
+func MonadTraverseArrayWithIndex[GB ~func() ET.Either[E, B], GBS ~func() ET.Either[E, BBS], AAS ~[]A, BBS ~[]B, E, A, B any](tas AAS, f func(int, A) GB) GBS {
+	return RA.MonadTraverseWithIndex[AAS](
+		Of[GBS, E, BBS],
+		Map[GBS, func() ET.Either[E, func(B) BBS], E, BBS, func(B) BBS],
+		Ap[GBS, func() ET.Either[E, func(B) BBS], GB],
+
+		tas,
+		f,
+	)
+}
+
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[GB ~func() ET.Either[E, B], GBS ~func() ET.Either[E, BBS], AAS ~[]A, BBS ~[]B, E, A, B any](f func(int, A) GB) func(AAS) GBS {
+	return RA.TraverseWithIndex[AAS](
+		Of[GBS, E, BBS],
+		Map[GBS, func() ET.Either[E, func(B) BBS], E, BBS, func(B) BBS],
+		Ap[GBS, func() ET.Either[E, func(B) BBS], GB],
+
+		f,
+	)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[GA ~func() ET.Either[E, A], GAS ~func() ET.Either[E, AAS], AAS ~[]A, GAAS ~[]GA, E, A any](tas GAAS) GAS {
 	return MonadTraverseArray[GA, GAS](tas, F.Identity[GA])
@@ -73,6 +96,17 @@ func TraverseRecord[GB ~func() ET.Either[E, B], GBS ~func() ET.Either[E, BBS], A
 	)
 }
 
+// TraverseRecordWithIndex transforms an array
+func TraverseRecordWithIndex[GB ~func() ET.Either[E, B], GBS ~func() ET.Either[E, BBS], AAS ~map[K]A, BBS ~map[K]B, K comparable, E, A, B any](f func(K, A) GB) func(AAS) GBS {
+	return RR.TraverseWithIndex[AAS](
+		Of[GBS, E, BBS],
+		Map[GBS, func() ET.Either[E, func(B) BBS], E, BBS, func(B) BBS],
+		Ap[GBS, func() ET.Either[E, func(B) BBS], GB],
+
+		f,
+	)
+}
+
 // SequenceRecord converts a homogeneous sequence of either into an either of sequence
 func SequenceRecord[GA ~func() ET.Either[E, A], GAS ~func() ET.Either[E, AAS], AAS ~map[K]A, GAAS ~map[K]GA, K comparable, E, A any](tas GAAS) GAS {
 	return MonadTraverseRecord[GA, GAS](tas, F.Identity[GA])

ioeither/traverse.go

@@ -24,6 +24,11 @@ func TraverseArray[E, A, B any](f func(A) IOEither[E, B]) func([]A) IOEither[E,
 	return G.TraverseArray[IOEither[E, B], IOEither[E, []B], []A](f)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[E, A, B any](f func(int, A) IOEither[E, B]) func([]A) IOEither[E, []B] {
+	return G.TraverseArrayWithIndex[IOEither[E, B], IOEither[E, []B], []A](f)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[E, A any](ma []IOEither[E, A]) IOEither[E, []A] {
 	return G.SequenceArray[IOEither[E, A], IOEither[E, []A]](ma)
@@ -34,6 +39,11 @@ func TraverseRecord[K comparable, E, A, B any](f func(A) IOEither[E, B]) func(ma
 	return G.TraverseRecord[IOEither[E, B], IOEither[E, map[K]B], map[K]A](f)
 }
 
+// TraverseRecordWithIndex transforms a record
+func TraverseRecordWithIndex[K comparable, E, A, B any](f func(K, A) IOEither[E, B]) func(map[K]A) IOEither[E, map[K]B] {
+	return G.TraverseRecordWithIndex[IOEither[E, B], IOEither[E, map[K]B], map[K]A](f)
+}
+
 // SequenceRecord converts a homogeneous sequence of either into an either of sequence
 func SequenceRecord[K comparable, E, A any](ma map[K]IOEither[E, A]) IOEither[E, map[K]A] {
 	return G.SequenceRecord[IOEither[E, A], IOEither[E, map[K]A]](ma)

ioeither/traverse_test.go

@@ -0,0 +1,37 @@
+// 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 (
+	"fmt"
+	"testing"
+
+	A "github.com/IBM/fp-go/array"
+	E "github.com/IBM/fp-go/either"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTraverseArray(t *testing.T) {
+
+	src := A.From("A", "B")
+
+	trfrm := TraverseArrayWithIndex(func(idx int, data string) IOEither[error, string] {
+		return Of[error](fmt.Sprintf("idx: %d, data: %s", idx, data))
+	})
+
+	assert.Equal(t, E.Of[error](A.From("idx: 0, data: A", "idx: 1, data: B")), trfrm(src)())
+
+}

iooption/array.go

@@ -24,6 +24,11 @@ func TraverseArray[A, B any](f func(A) IOOption[B]) func([]A) IOOption[[]B] {
 	return G.TraverseArray[IOOption[B], IOOption[[]B], []A](f)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[A, B any](f func(int, A) IOOption[B]) func([]A) IOOption[[]B] {
+	return G.TraverseArrayWithIndex[IOOption[B], IOOption[[]B], []A](f)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[A any](ma []IOOption[A]) IOOption[[]A] {
 	return G.SequenceArray[IOOption[A], IOOption[[]A], []IOOption[A], []A, A](ma)

iooption/generic/traverse.go

@@ -28,6 +28,13 @@ func TraverseArray[TB ~func() O.Option[B], TBS ~func() O.Option[GB], GA ~[]A, GB
 	)
 }
 
+func TraverseArrayWithIndex[TB ~func() O.Option[B], TBS ~func() O.Option[GB], GA ~[]A, GB ~[]B, A, B any](f func(int, A) TB) func(GA) TBS {
+	return F.Flow2(
+		I.TraverseArrayWithIndex[TB, func() []O.Option[B], GA](f),
+		I.Map[func() []O.Option[B], TBS](O.SequenceArrayG[GB, []O.Option[B], B]),
+	)
+}
+
 func SequenceArray[TB ~func() O.Option[B], TBS ~func() O.Option[GB], GA ~[]TB, GB ~[]B, A, B any](ma GA) TBS {
 	return TraverseArray[TB, TBS, GA](F.Identity[TB])(ma)
 }

lazy/traverse.go

@@ -29,6 +29,12 @@ func TraverseArray[A, B any](f func(A) Lazy[B]) func([]A) Lazy[[]B] {
 	return G.TraverseArray[Lazy[B], Lazy[[]B], []A](f)
 }
 
+// TraverseArrayWithIndex applies a function returning an [IO] to all elements in an array and the
+// transforms this into an [IO] of that array
+func TraverseArrayWithIndex[A, B any](f func(int, A) Lazy[B]) func([]A) Lazy[[]B] {
+	return G.TraverseArrayWithIndex[Lazy[B], Lazy[[]B], []A](f)
+}
+
 // SequenceArray converts an array of [IO] to an [IO] of an array
 func SequenceArray[A any](tas []Lazy[A]) Lazy[[]A] {
 	return G.SequenceArray[Lazy[A], Lazy[[]A]](tas)
@@ -38,12 +44,18 @@ func MonadTraverseRecord[K comparable, A, B any](tas map[K]A, f func(A) Lazy[B])
 	return G.MonadTraverseRecord[Lazy[B], Lazy[map[K]B]](tas, f)
 }
 
-// TraverseArray applies a function returning an [IO] to all elements in a record and the
+// TraverseRecord applies a function returning an [IO] to all elements in a record and the
 // transforms this into an [IO] of that record
 func TraverseRecord[K comparable, A, B any](f func(A) Lazy[B]) func(map[K]A) Lazy[map[K]B] {
 	return G.TraverseRecord[Lazy[B], Lazy[map[K]B], map[K]A](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 TraverseRecordWithIndex[K comparable, A, B any](f func(K, A) Lazy[B]) func(map[K]A) Lazy[map[K]B] {
+	return G.TraverseRecordWithIndex[Lazy[B], Lazy[map[K]B], map[K]A](f)
+}
+
 // SequenceRecord converts a record of [IO] to an [IO] of a record
 func SequenceRecord[K comparable, A any](tas map[K]Lazy[A]) Lazy[map[K]A] {
 	return G.SequenceRecord[Lazy[A], Lazy[map[K]A]](tas)

option/array.go

@@ -36,6 +36,22 @@ func TraverseArray[A, B any](f func(A) Option[B]) func([]A) Option[[]B] {
 	return TraverseArrayG[[]A, []B](f)
 }
 
+// TraverseArrayWithIndexG transforms an array
+func TraverseArrayWithIndexG[GA ~[]A, GB ~[]B, A, B any](f func(int, A) Option[B]) func(GA) Option[GB] {
+	return RA.TraverseWithIndex[GA](
+		Of[GB],
+		Map[GB, func(B) GB],
+		Ap[GB, B],
+
+		f,
+	)
+}
+
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[A, B any](f func(int, A) Option[B]) func([]A) Option[[]B] {
+	return TraverseArrayWithIndexG[[]A, []B](f)
+}
+
 func SequenceArrayG[GA ~[]A, GOA ~[]Option[A], A any](ma GOA) Option[GA] {
 	return TraverseArrayG[GOA, GA](F.Identity[Option[A]])(ma)
 }

option/record.go

@@ -20,7 +20,7 @@ import (
 	RR "github.com/IBM/fp-go/internal/record"
 )
 
-// TraverseRecord transforms a record of options into an option of a record
+// TraverseRecordG transforms a record of options into an option of a record
 func TraverseRecordG[GA ~map[K]A, GB ~map[K]B, K comparable, A, B any](f func(A) Option[B]) func(GA) Option[GB] {
 	return RR.Traverse[GA](
 		Of[GB],
@@ -36,6 +36,22 @@ func TraverseRecord[K comparable, A, B any](f func(A) Option[B]) func(map[K]A) O
 	return TraverseRecordG[map[K]A, map[K]B](f)
 }
 
+// TraverseRecordWithIndexG transforms a record of options into an option of a record
+func TraverseRecordWithIndexG[GA ~map[K]A, GB ~map[K]B, K comparable, A, B any](f func(K, A) Option[B]) func(GA) Option[GB] {
+	return RR.TraverseWithIndex[GA](
+		Of[GB],
+		Map[GB, func(B) GB],
+		Ap[GB, B],
+
+		f,
+	)
+}
+
+// TraverseRecordWithIndex transforms a record of options into an option of a record
+func TraverseRecordWithIndex[K comparable, A, B any](f func(K, A) Option[B]) func(map[K]A) Option[map[K]B] {
+	return TraverseRecordWithIndexG[map[K]A, map[K]B](f)
+}
+
 func SequenceRecordG[GA ~map[K]A, GOA ~map[K]Option[A], K comparable, A any](ma GOA) Option[GA] {
 	return TraverseRecordG[GOA, GA](F.Identity[Option[A]])(ma)
 }

reader/array.go

@@ -24,6 +24,11 @@ func TraverseArray[R, A, B any](f func(A) Reader[R, B]) func([]A) Reader[R, []B]
 	return G.TraverseArray[Reader[R, B], Reader[R, []B], []A](f)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[R, A, B any](f func(int, A) Reader[R, B]) func([]A) Reader[R, []B] {
+	return G.TraverseArrayWithIndex[Reader[R, B], Reader[R, []B], []A](f)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[R, A any](ma []Reader[R, A]) Reader[R, []A] {
 	return G.SequenceArray[Reader[R, A], Reader[R, []A]](ma)

reader/generic/array.go

@@ -40,6 +40,16 @@ func TraverseArray[GB ~func(R) B, GBS ~func(R) BBS, AAS ~[]A, BBS ~[]B, R, A, B
 	)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[GB ~func(R) B, GBS ~func(R) BBS, AAS ~[]A, BBS ~[]B, R, A, B any](f func(int, A) GB) func(AAS) GBS {
+	return RA.TraverseWithIndex[AAS](
+		Of[GBS, R, BBS],
+		Map[GBS, func(R) func(B) BBS, R, BBS, func(B) BBS],
+		Ap[GB, GBS, func(R) func(B) BBS, R, B, BBS],
+		f,
+	)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[GA ~func(R) A, GAS ~func(R) AAS, AAS ~[]A, GAAS ~[]GA, R, A any](ma GAAS) GAS {
 	return MonadTraverseArray[GA, GAS](ma, F.Identity[GA])

readereither/array.go

@@ -24,6 +24,11 @@ func TraverseArray[E, L, A, B any](f func(A) ReaderEither[E, L, B]) func([]A) Re
 	return G.TraverseArray[ReaderEither[E, L, B], ReaderEither[E, L, []B], []A](f)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[E, L, A, B any](f func(int, A) ReaderEither[E, L, B]) func([]A) ReaderEither[E, L, []B] {
+	return G.TraverseArrayWithIndex[ReaderEither[E, L, B], ReaderEither[E, L, []B], []A](f)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[E, L, A any](ma []ReaderEither[E, L, A]) ReaderEither[E, L, []A] {
 	return G.SequenceArray[ReaderEither[E, L, A], ReaderEither[E, L, []A]](ma)

readereither/generic/array.go

@@ -43,6 +43,17 @@ func TraverseArray[GB ~func(E) ET.Either[L, B], GBS ~func(E) ET.Either[L, BBS],
 	)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[GB ~func(E) ET.Either[L, B], GBS ~func(E) ET.Either[L, BBS], AAS ~[]A, BBS ~[]B, L, E, A, B any](f func(int, A) GB) func(AAS) GBS {
+	return RA.TraverseWithIndex[AAS](
+		Of[GBS, L, E, BBS],
+		Map[GBS, func(E) ET.Either[L, func(B) BBS], L, E, BBS, func(B) BBS],
+		Ap[GB, GBS, func(E) ET.Either[L, func(B) BBS], L, E, B, BBS],
+
+		f,
+	)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[GA ~func(E) ET.Either[L, A], GAS ~func(E) ET.Either[L, AAS], AAS ~[]A, GAAS ~[]GA, L, E, A any](ma GAAS) GAS {
 	return MonadTraverseArray[GA, GAS](ma, F.Identity[GA])

readerio/array.go

@@ -25,6 +25,11 @@ func TraverseArray[R, A, B any](f func(A) ReaderIO[R, B]) func([]A) ReaderIO[R,
 	return G.TraverseArray[ReaderIO[R, B], ReaderIO[R, []B], IO.IO[B], IO.IO[[]B], []A](f)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[R, A, B any](f func(int, A) ReaderIO[R, B]) func([]A) ReaderIO[R, []B] {
+	return G.TraverseArrayWithIndex[ReaderIO[R, B], ReaderIO[R, []B], IO.IO[B], IO.IO[[]B], []A](f)
+}
+
 // SequenceArray converts a homogeneous sequence of Readers into a Reader of sequence
 func SequenceArray[R, A any](ma []ReaderIO[R, A]) ReaderIO[R, []A] {
 	return G.SequenceArray[ReaderIO[R, A], ReaderIO[R, []A]](ma)

readerio/generic/array.go

@@ -42,6 +42,17 @@ func TraverseArray[GB ~func(E) GIOB, GBS ~func(E) GIOBS, GIOB ~func() B, GIOBS ~
 	)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[GB ~func(E) GIOB, GBS ~func(E) GIOBS, GIOB ~func() B, GIOBS ~func() BBS, AAS ~[]A, BBS ~[]B, E, A, B any](f func(int, A) GB) func(AAS) GBS {
+	return RA.TraverseWithIndex[AAS](
+		Of[GBS, GIOBS, E, BBS],
+		Map[GBS, func(E) func() func(B) BBS, GIOBS, func() func(B) BBS, E, BBS, func(B) BBS],
+		Ap[GB, GBS, func(E) func() func(B) BBS, GIOB, GIOBS, func() func(B) BBS, E, B, BBS],
+
+		f,
+	)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[GA ~func(E) GIOA, GAS ~func(E) GIOAS, GIOA ~func() A, GIOAS ~func() AAS, AAS ~[]A, GAAS ~[]GA, E, A any](ma GAAS) GAS {
 	return MonadTraverseArray[GA, GAS](ma, F.Identity[GA])

readerioeither/generic/traverse.go

@@ -44,6 +44,17 @@ func TraverseArray[GB ~func(E) GIOB, GBS ~func(E) GIOBS, GIOB ~func() ET.Either[
 	)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[GB ~func(E) GIOB, GBS ~func(E) GIOBS, GIOB ~func() ET.Either[L, B], GIOBS ~func() ET.Either[L, BBS], AAS ~[]A, BBS ~[]B, E, L, A, B any](f func(int, A) GB) func(AAS) GBS {
+	return RA.TraverseWithIndex[AAS](
+		Of[GBS, GIOBS, E, L, BBS],
+		Map[GBS, func(E) func() ET.Either[L, func(B) BBS], GIOBS, func() ET.Either[L, func(B) BBS], E, L, BBS, func(B) BBS],
+		Ap[GB, GBS, func(E) func() ET.Either[L, func(B) BBS], GIOB, GIOBS, func() ET.Either[L, func(B) BBS], E, L, B, BBS],
+
+		f,
+	)
+}
+
 // SequenceArray converts a homogeneous sequence of either into an either of sequence
 func SequenceArray[GA ~func(E) GIOA, GAS ~func(E) GIOAS, GIOA ~func() ET.Either[L, A], GIOAS ~func() ET.Either[L, AAS], AAS ~[]A, GAAS ~[]GA, E, L, A any](ma GAAS) GAS {
 	return MonadTraverseArray[GA, GAS](ma, F.Identity[GA])
@@ -61,7 +72,7 @@ func MonadTraverseRecord[GB ~func(C) GIOB, GBS ~func(C) GIOBS, GIOB ~func() ET.E
 	)
 }
 
-// TraverseRecord transforms an array
+// TraverseRecord transforms a record
 func TraverseRecord[GB ~func(C) GIOB, GBS ~func(C) GIOBS, GIOB ~func() ET.Either[E, B], GIOBS ~func() ET.Either[E, BBS], AAS ~map[K]A, BBS ~map[K]B, K comparable, C, E, A, B any](f func(A) GB) func(AAS) GBS {
 	return RR.Traverse[AAS](
 		Of[GBS, GIOBS, C, E, BBS],
@@ -72,6 +83,17 @@ func TraverseRecord[GB ~func(C) GIOB, GBS ~func(C) GIOBS, GIOB ~func() ET.Either
 	)
 }
 
+// TraverseRecordWithIndex transforms a record
+func TraverseRecordWithIndex[GB ~func(C) GIOB, GBS ~func(C) GIOBS, GIOB ~func() ET.Either[E, B], GIOBS ~func() ET.Either[E, BBS], AAS ~map[K]A, BBS ~map[K]B, K comparable, C, E, A, B any](f func(K, A) GB) func(AAS) GBS {
+	return RR.TraverseWithIndex[AAS](
+		Of[GBS, GIOBS, C, E, BBS],
+		Map[GBS, func(C) func() ET.Either[E, func(B) BBS], GIOBS, func() ET.Either[E, func(B) BBS], C, E, BBS, func(B) BBS],
+		Ap[GB, GBS, func(C) func() ET.Either[E, func(B) BBS], GIOB, GIOBS, func() ET.Either[E, func(B) BBS], C, E, B, BBS],
+
+		f,
+	)
+}
+
 // SequenceRecord converts a homogeneous sequence of either into an either of sequence
 func SequenceRecord[GA ~func(C) GIOA, GAS ~func(C) GIOAS, GIOA ~func() ET.Either[E, A], GIOAS ~func() ET.Either[E, AAS], AAS ~map[K]A, GAAS ~map[K]GA, K comparable, C, E, A any](tas GAAS) GAS {
 	return MonadTraverseRecord[GA, GAS](tas, F.Identity[GA])

readerioeither/traverse.go

@@ -25,6 +25,11 @@ func TraverseArray[R, E, A, B any](f func(A) ReaderIOEither[R, E, B]) func([]A)
 	return G.TraverseArray[ReaderIOEither[R, E, B], ReaderIOEither[R, E, []B], IOE.IOEither[E, B], IOE.IOEither[E, []B], []A](f)
 }
 
+// TraverseArrayWithIndex transforms an array
+func TraverseArrayWithIndex[R, E, A, B any](f func(int, A) ReaderIOEither[R, E, B]) func([]A) ReaderIOEither[R, E, []B] {
+	return G.TraverseArrayWithIndex[ReaderIOEither[R, E, B], ReaderIOEither[R, E, []B], IOE.IOEither[E, B], IOE.IOEither[E, []B], []A](f)
+}
+
 // SequenceArray converts a homogeneous sequence of Readers into a Reader of a sequence
 func SequenceArray[R, E, A any](ma []ReaderIOEither[R, E, A]) ReaderIOEither[R, E, []A] {
 	return G.SequenceArray[ReaderIOEither[R, E, A], ReaderIOEither[R, E, []A]](ma)
@@ -35,6 +40,11 @@ func TraverseRecord[R any, K comparable, E, A, B any](f func(A) ReaderIOEither[R
 	return G.TraverseRecord[ReaderIOEither[R, E, B], ReaderIOEither[R, E, map[K]B], IOE.IOEither[E, B], IOE.IOEither[E, map[K]B], map[K]A](f)
 }
 
+// TraverseRecordWithIndex transforms an array
+func TraverseRecordWithIndex[R any, K comparable, E, A, B any](f func(K, A) ReaderIOEither[R, E, B]) func(map[K]A) ReaderIOEither[R, E, map[K]B] {
+	return G.TraverseRecordWithIndex[ReaderIOEither[R, E, B], ReaderIOEither[R, E, map[K]B], IOE.IOEither[E, B], IOE.IOEither[E, map[K]B], map[K]A](f)
+}
+
 // SequenceRecord converts a homogeneous sequence of Readers into a Reader of a sequence
 func SequenceRecord[R any, K comparable, E, A any](ma map[K]ReaderIOEither[R, E, A]) ReaderIOEither[R, E, map[K]A] {
 	return G.SequenceRecord[ReaderIOEither[R, E, A], ReaderIOEither[R, E, map[K]A]](ma)