fix: refactor writer

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

identity/generic/identity.go

@@ -50,7 +50,11 @@ func MonadChainFirst[GAB ~func(A) B, A, B any](fa A, f GAB) A {
 }
 
 func ChainFirst[GAB ~func(A) B, A, B any](f GAB) func(A) A {
-	return C.ChainFirst(MonadChain[func(A) A, A, A], MonadMap[func(B) A, B, A], f)
+	return C.ChainFirst(
+		Chain[func(A) A, A, A],
+		Map[func(B) A, B, A],
+		f,
+	)
 }
 
 func MonadFlap[GAB ~func(A) B, A, B any](fab GAB, a A) B {

internal/chain/chain.go

@@ -43,11 +43,11 @@ func MonadChain[A, B, HKTA, HKTB any](
 // HKTA=HKT[A]
 // HKTB=HKT[B]
 func ChainFirst[A, B, HKTA, HKTB any](
-	mchain func(HKTA, func(A) HKTA) HKTA,
+	mchain func(func(A) HKTA) func(HKTA) HKTA,
-	mmap func(HKTB, func(B) A) HKTA,
+	mmap func(func(B) A) func(HKTB) HKTA,
 	f func(A) HKTB) func(HKTA) HKTA {
-	return F.Bind2nd(mchain, func(a A) HKTA {
+	return mchain(func(a A) HKTA {
-		return mmap(f(a), F.Constant1[B](a))
+		return mmap(F.Constant1[B](a))(f(a))
 	})
 }
 

internal/fromeither/either.go

@@ -85,8 +85,8 @@ func MonadChainFirstEitherK[A, E, B, HKTEA, HKTEB any](
 }
 
 func ChainFirstEitherK[A, E, B, HKTEA, HKTEB any](
-	mchain func(HKTEA, func(A) HKTEA) HKTEA,
+	mchain func(func(A) HKTEA) func(HKTEA) HKTEA,
-	mmap func(HKTEB, func(B) A) HKTEA,
+	mmap func(func(B) A) func(HKTEB) HKTEA,
 	fromEither func(ET.Either[E, B]) HKTEB,
 	f func(A) ET.Either[E, B]) func(HKTEA) HKTEA {
 	return C.ChainFirst(mchain, mmap, F.Flow2(f, fromEither))

internal/fromio/io.go

@@ -30,8 +30,8 @@ func MonadChainFirstIOK[A, B, HKTA, HKTB any, GIOB ~func() B](
 }
 
 func ChainFirstIOK[A, B, HKTA, HKTB any, GIOB ~func() B](
-	mchain func(HKTA, func(A) HKTA) HKTA,
+	mchain func(func(A) HKTA) func(HKTA) HKTA,
-	mmap func(HKTB, func(B) A) HKTA,
+	mmap func(func(B) A) func(HKTB) HKTA,
 	fromio func(GIOB) HKTB,
 	f func(A) GIOB) func(HKTA) HKTA {
 	// chain

internal/fromioeither/ioeither.go

@@ -31,8 +31,8 @@ func MonadChainFirstIOEitherK[GIOB ~func() ET.Either[E, B], E, A, B, HKTA, HKTB
 }
 
 func ChainFirstIOEitherK[GIOB ~func() ET.Either[E, B], E, A, B, HKTA, HKTB any](
-	mchain func(HKTA, func(A) HKTA) HKTA,
+	mchain func(func(A) HKTA) func(HKTA) HKTA,
-	mmap func(HKTB, func(B) A) HKTA,
+	mmap func(func(B) A) func(HKTB) HKTA,
 	fromio func(GIOB) HKTB,
 	f func(A) GIOB) func(HKTA) HKTA {
 	// chain

io/generic/io.go

@@ -100,7 +100,11 @@ func MonadChainFirst[GA ~func() A, GB ~func() B, A, B any](fa GA, f func(A) GB)
 // ChainFirst composes computations in sequence, using the return value of one computation to determine the next computation and
 // keeping only the result of the first.
 func ChainFirst[GA ~func() A, GB ~func() B, A, B any](f func(A) GB) func(GA) GA {
-	return C.ChainFirst(MonadChain[GA, GA, A, A], MonadMap[GB, GA, B, A], f)
+	return C.ChainFirst(
+		Chain[GA, GA, A, A],
+		Map[GB, GA, B, A],
+		f,
+	)
 }
 
 func ApSeq[GB ~func() B, GAB ~func() func(A) B, GA ~func() A, B, A any](ma GA) func(GAB) GB {

ioeither/generic/ioeither.go

@@ -257,8 +257,8 @@ func MonadChainFirst[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E,
 // ChainFirst runs the monad returned by the function but returns the result of the original monad
 func ChainFirst[GA ~func() ET.Either[E, A], GB ~func() ET.Either[E, B], E, A, B any](f func(A) GB) func(GA) GA {
 	return C.ChainFirst(
-		MonadChain[GA, GA, E, A, A],
+		Chain[GA, GA, E, A, A],
-		MonadMap[GB, GA, E, B, A],
+		Map[GB, GA, E, B, A],
 		f,
 	)
 }
@@ -277,8 +277,8 @@ func MonadChainFirstIOK[GA ~func() ET.Either[E, A], GIOB ~func() B, E, A, B any]
 // ChainFirstIOK runs the monad returned by the function but returns the result of the original monad
 func ChainFirstIOK[GA ~func() ET.Either[E, A], GIOB ~func() B, E, A, B any](f func(A) GIOB) func(GA) GA {
 	return FI.ChainFirstIOK(
-		MonadChain[GA, GA, E, A, A],
+		Chain[GA, GA, E, A, A],
-		MonadMap[func() ET.Either[E, B], GA, E, B, A],
+		Map[func() ET.Either[E, B], GA, E, B, A],
 		FromIO[func() ET.Either[E, B], GIOB, E, B],
 		f,
 	)
@@ -298,8 +298,8 @@ func MonadChainFirstEitherK[GA ~func() ET.Either[E, A], E, A, B any](first GA, f
 // ChainFirstEitherK runs the monad returned by the function but returns the result of the original monad
 func ChainFirstEitherK[GA ~func() ET.Either[E, A], E, A, B any](f func(A) ET.Either[E, B]) func(GA) GA {
 	return FE.ChainFirstEitherK(
-		MonadChain[GA, GA, E, A, A],
+		Chain[GA, GA, E, A, A],
-		MonadMap[func() ET.Either[E, B], GA, E, B, A],
+		Map[func() ET.Either[E, B], GA, E, B, A],
 		FromEither[func() ET.Either[E, B], E, B],
 		f,
 	)

iooption/generic/iooption.go

@@ -90,8 +90,8 @@ func MonadChainFirst[GA ~func() O.Option[A], GB ~func() O.Option[B], A, B any](m
 // ChainFirst runs the monad returned by the function but returns the result of the original monad
 func ChainFirst[GA ~func() O.Option[A], GB ~func() O.Option[B], A, B any](f func(A) GB) func(GA) GA {
 	return C.ChainFirst(
-		MonadChain[GA, GA, A, A],
+		Chain[GA, GA, A, A],
-		MonadMap[GB, GA, B, A],
+		Map[GB, GA, B, A],
 		f,
 	)
 }
@@ -110,8 +110,8 @@ func MonadChainFirstIOK[GA ~func() O.Option[A], GIOB ~func() B, A, B any](first
 // ChainFirstIOK runs the monad returned by the function but returns the result of the original monad
 func ChainFirstIOK[GA ~func() O.Option[A], GIOB ~func() B, A, B any](f func(A) GIOB) func(GA) GA {
 	return FI.ChainFirstIOK(
-		MonadChain[GA, GA, A, A],
+		Chain[GA, GA, A, A],
-		MonadMap[func() O.Option[B], GA, B, A],
+		Map[func() O.Option[B], GA, B, A],
 		FromIO[func() O.Option[B], GIOB, B],
 		f,
 	)

readerio/generic/reader.go

@@ -114,8 +114,8 @@ func MonadChainFirstIOK[GEA ~func(E) GIOA, GEB ~func(E) GIOB, GIOA ~func() A, GI
 
 func ChainFirstIOK[GEA ~func(E) GIOA, GEB ~func(E) GIOB, GIOA ~func() A, GIOB ~func() B, E, A, B any](f func(A) GIOB) func(GEA) GEA {
 	return FIO.ChainFirstIOK(
-		MonadChain[GEA, GEA],
+		Chain[GEA, GEA],
-		MonadMap[GEB, GEA],
+		Map[GEB, GEA],
 		FromIO[GEB],
 		f,
 	)

writer/bind.go

@@ -17,7 +17,6 @@ package writer
 
 import (
 	M "github.com/IBM/fp-go/monoid"
-	S "github.com/IBM/fp-go/semigroup"
 	G "github.com/IBM/fp-go/writer/generic"
 )
 
@@ -27,11 +26,11 @@ func Do[S, W any](m M.Monoid[W]) func(S) Writer[W, S] {
 }
 
 // Bind attaches the result of a computation to a context [S1] to produce a context [S2]
-func Bind[S1, S2, T, W any](s S.Semigroup[W]) func(
+func Bind[S1, S2, T, W any](
 	setter func(T) func(S1) S2,
 	f func(S1) Writer[W, T],
 ) func(Writer[W, S1]) Writer[W, S2] {
-	return G.Bind[Writer[W, S1], Writer[W, S2], Writer[W, T], W, S1, S2, T](s)
+	return G.Bind[Writer[W, S1], Writer[W, S2], Writer[W, T], W, S1, S2, T](setter, f)
 }
 
 // Let attaches the result of a computation to a context [S1] to produce a context [S2]
@@ -58,9 +57,9 @@ func BindTo[W, S1, T any](
 }
 
 // ApS attaches a value to a context [S1] to produce a context [S2] by considering the context and the value concurrently
-func ApS[S1, S2, T, W any](s S.Semigroup[W]) func(
+func ApS[S1, S2, T, W any](
 	setter func(T) func(S1) S2,
 	fa Writer[W, T],
 ) func(Writer[W, S1]) Writer[W, S2] {
-	return G.ApS[Writer[W, S1], Writer[W, S2], Writer[W, T], W, S1, S2, T](s)
+	return G.ApS[Writer[W, S1], Writer[W, S2], Writer[W, T], W, S1, S2, T](setter, fa)
 }

writer/bind_test.go

@@ -42,8 +42,8 @@ func TestBind(t *testing.T) {
 
 	res := F.Pipe3(
 		Do[utils.Initial](monoid)(utils.Empty),
-		Bind[utils.Initial, utils.WithLastName, string](sg)(utils.SetLastName, getLastName),
+		Bind(utils.SetLastName, getLastName),
-		Bind[utils.WithLastName, utils.WithGivenName, string](sg)(utils.SetGivenName, getGivenName),
+		Bind(utils.SetGivenName, getGivenName),
 		Map[[]string](utils.GetFullName),
 	)
 
@@ -54,8 +54,8 @@ func TestApS(t *testing.T) {
 
 	res := F.Pipe3(
 		Do[utils.Initial](monoid)(utils.Empty),
-		ApS[utils.Initial, utils.WithLastName, string](sg)(utils.SetLastName, Of[string](monoid)("Doe")),
+		ApS(utils.SetLastName, Of[string](monoid)("Doe")),
-		ApS[utils.WithLastName, utils.WithGivenName, string](sg)(utils.SetGivenName, Of[string](monoid)("John")),
+		ApS(utils.SetGivenName, Of[string](monoid)("John")),
 		Map[[]string](utils.GetFullName),
 	)
 

writer/generic/bind.go

@@ -20,36 +20,30 @@ import (
 	C "github.com/IBM/fp-go/internal/chain"
 	F "github.com/IBM/fp-go/internal/functor"
 	M "github.com/IBM/fp-go/monoid"
-	S "github.com/IBM/fp-go/semigroup"
+	SG "github.com/IBM/fp-go/semigroup"
 	T "github.com/IBM/fp-go/tuple"
 )
 
 // Bind creates an empty context of type [S] to be used with the [Bind] operation
-func Do[GS ~func() T.Tuple2[S, W], W, S any](m M.Monoid[W]) func(S) GS {
+func Do[GS ~func() T.Tuple3[S, W, SG.Semigroup[W]], W, S any](m M.Monoid[W]) func(S) GS {
 	return Of[GS, W, S](m)
 }
 
 // Bind attaches the result of a computation to a context [S1] to produce a context [S2]
-func Bind[GS1 ~func() T.Tuple2[S1, W], GS2 ~func() T.Tuple2[S2, W], GT ~func() T.Tuple2[A, W], W, S1, S2, A any](s S.Semigroup[W]) func(
+func Bind[GS1 ~func() T.Tuple3[S1, W, SG.Semigroup[W]], GS2 ~func() T.Tuple3[S2, W, SG.Semigroup[W]], GT ~func() T.Tuple3[A, W, SG.Semigroup[W]], W, S1, S2, A any](
 	setter func(A) func(S1) S2,
 	f func(S1) GT,
 ) func(GS1) GS2 {
-	ch := Chain[GS2, GS1, func(S1) GS2, W, S1, S2](s)
+	return C.Bind(
-	return func(
+		Chain[GS2, GS1, func(S1) GS2, W, S1, S2],
-		setter func(A) func(S1) S2,
+		Map[GS2, GT, func(A) S2, W, A, S2],
-		f func(S1) GT,
+		setter,
-	) func(GS1) GS2 {
+		f,
-		return C.Bind(
+	)
-			ch,
-			Map[GS2, GT, func(A) S2, W, A, S2],
-			setter,
-			f,
-		)
-	}
 }
 
 // Let attaches the result of a computation to a context [S1] to produce a context [S2]
-func Let[GS1 ~func() T.Tuple2[S1, W], GS2 ~func() T.Tuple2[S2, W], W, S1, S2, A any](
+func Let[GS1 ~func() T.Tuple3[S1, W, SG.Semigroup[W]], GS2 ~func() T.Tuple3[S2, W, SG.Semigroup[W]], W, S1, S2, A any](
 	key func(A) func(S1) S2,
 	f func(S1) A,
 ) func(GS1) GS2 {
@@ -61,7 +55,7 @@ func Let[GS1 ~func() T.Tuple2[S1, W], GS2 ~func() T.Tuple2[S2, W], W, S1, S2, A
 }
 
 // LetTo attaches the a value to a context [S1] to produce a context [S2]
-func LetTo[GS1 ~func() T.Tuple2[S1, W], GS2 ~func() T.Tuple2[S2, W], W, S1, S2, B any](
+func LetTo[GS1 ~func() T.Tuple3[S1, W, SG.Semigroup[W]], GS2 ~func() T.Tuple3[S2, W, SG.Semigroup[W]], W, S1, S2, B any](
 	key func(B) func(S1) S2,
 	b B,
 ) func(GS1) GS2 {
@@ -73,7 +67,7 @@ func LetTo[GS1 ~func() T.Tuple2[S1, W], GS2 ~func() T.Tuple2[S2, W], W, S1, S2,
 }
 
 // BindTo initializes a new state [S1] from a value [T]
-func BindTo[GS1 ~func() T.Tuple2[S1, W], GT ~func() T.Tuple2[A, W], W, S1, A any](
+func BindTo[GS1 ~func() T.Tuple3[S1, W, SG.Semigroup[W]], GT ~func() T.Tuple3[A, W, SG.Semigroup[W]], W, S1, A any](
 	setter func(A) S1,
 ) func(GT) GS1 {
 	return C.BindTo(
@@ -83,20 +77,14 @@ func BindTo[GS1 ~func() T.Tuple2[S1, W], GT ~func() T.Tuple2[A, W], W, S1, A any
 }
 
 // ApS attaches a value to a context [S1] to produce a context [S2] by considering the context and the value concurrently
-func ApS[GS1 ~func() T.Tuple2[S1, W], GS2 ~func() T.Tuple2[S2, W], GT ~func() T.Tuple2[A, W], W, S1, S2, A any](s S.Semigroup[W]) func(
+func ApS[GS1 ~func() T.Tuple3[S1, W, SG.Semigroup[W]], GS2 ~func() T.Tuple3[S2, W, SG.Semigroup[W]], GT ~func() T.Tuple3[A, W, SG.Semigroup[W]], W, S1, S2, A any](
 	setter func(A) func(S1) S2,
 	fa GT,
 ) func(GS1) GS2 {
-	ap := Ap[GS2, func() T.Tuple2[func(A) S2, W], GT, W, A, S2](s)
+	return apply.ApS(
-	return func(
+		Ap[GS2, func() T.Tuple3[func(A) S2, W, SG.Semigroup[W]], GT, W, A, S2],
-		setter func(A) func(S1) S2,
+		Map[func() T.Tuple3[func(A) S2, W, SG.Semigroup[W]], GS1, func(S1) func(A) S2],
-		fa GT,
+		setter,
-	) func(GS1) GS2 {
+		fa,
-		return apply.ApS(
+	)
-			ap,
-			Map[func() T.Tuple2[func(A) S2, W], GS1, func(S1) func(A) S2],
-			setter,
-			fa,
-		)
-	}
 }

writer/generic/eq.go

@@ -17,11 +17,12 @@ package generic
 
 import (
 	EQ "github.com/IBM/fp-go/eq"
+	SG "github.com/IBM/fp-go/semigroup"
 	T "github.com/IBM/fp-go/tuple"
 )
 
 // Constructs an equal predicate for a [Writer]
-func Eq[GA ~func() T.Tuple2[A, W], W, A any](w EQ.Eq[W], a EQ.Eq[A]) EQ.Eq[GA] {
+func Eq[GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], W, A any](w EQ.Eq[W], a EQ.Eq[A]) EQ.Eq[GA] {
 	return EQ.FromEquals(func(l, r GA) bool {
 		ll := l()
 		rr := r()
@@ -31,6 +32,6 @@ func Eq[GA ~func() T.Tuple2[A, W], W, A any](w EQ.Eq[W], a EQ.Eq[A]) EQ.Eq[GA] {
 }
 
 // FromStrictEquals constructs an [EQ.Eq] from the canonical comparison function
-func FromStrictEquals[GA ~func() T.Tuple2[A, W], W, A comparable]() EQ.Eq[GA] {
+func FromStrictEquals[GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], W, A comparable]() EQ.Eq[GA] {
 	return Eq[GA](EQ.FromStrictEquals[W](), EQ.FromStrictEquals[A]())
 }

writer/generic/writer.go

@@ -17,121 +17,118 @@ package generic
 
 import (
 	F "github.com/IBM/fp-go/function"
+	C "github.com/IBM/fp-go/internal/chain"
 	IO "github.com/IBM/fp-go/io/generic"
 	M "github.com/IBM/fp-go/monoid"
-	S "github.com/IBM/fp-go/semigroup"
+	SG "github.com/IBM/fp-go/semigroup"
 	T "github.com/IBM/fp-go/tuple"
 )
 
-func Of[GA ~func() T.Tuple2[A, W], W, A any](m M.Monoid[W]) func(A) GA {
+func Of[GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], W, A any](m M.Monoid[W]) func(A) GA {
 	return F.Flow2(
-		F.Bind2nd(T.MakeTuple2[A, W], m.Empty()),
+		F.Bind23of3(T.MakeTuple3[A, W, SG.Semigroup[W]])(m.Empty(), M.ToSemigroup(m)),
 		IO.Of[GA],
 	)
 }
 
 // Listen modifies the result to include the changes to the accumulator
-func Listen[GA ~func() T.Tuple2[A, W], GTA ~func() T.Tuple2[T.Tuple2[A, W], W], W, A any](fa GA) GTA {
+func Listen[GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], GTA ~func() T.Tuple3[T.Tuple2[A, W], W, SG.Semigroup[W]], W, A any](fa GA) GTA {
-	return func() T.Tuple2[T.Tuple2[A, W], W] {
+	return func() T.Tuple3[T.Tuple2[A, W], W, SG.Semigroup[W]] {
 		t := fa()
-		return T.MakeTuple2(T.MakeTuple2(t.F1, t.F2), t.F2)
+		return T.MakeTuple3(T.MakeTuple2(t.F1, t.F2), t.F2, t.F3)
 	}
 }
 
 // Pass applies the returned function to the accumulator
-func Pass[GFA ~func() T.Tuple2[T.Tuple2[A, FCT], W], GA ~func() T.Tuple2[A, W], FCT ~func(W) W, W, A any](fa GFA) GA {
+func Pass[GFA ~func() T.Tuple3[T.Tuple2[A, FCT], W, SG.Semigroup[W]], GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], FCT ~func(W) W, W, A any](fa GFA) GA {
-	return func() T.Tuple2[A, W] {
+	return func() T.Tuple3[A, W, SG.Semigroup[W]] {
 		t := fa()
-		return T.MakeTuple2(t.F1.F1, t.F1.F2(t.F2))
+		return T.MakeTuple3(t.F1.F1, t.F1.F2(t.F2), t.F3)
 	}
 }
 
-func MonadMap[GB ~func() T.Tuple2[B, W], GA ~func() T.Tuple2[A, W], FCT ~func(A) B, W, A, B any](fa GA, f FCT) GB {
+func MonadMap[GB ~func() T.Tuple3[B, W, SG.Semigroup[W]], GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], FCT ~func(A) B, W, A, B any](fa GA, f FCT) GB {
-	return IO.MonadMap[GA, GB](fa, T.Map2(f, F.Identity[W]))
+	return IO.MonadMap[GA, GB](fa, T.Map3(f, F.Identity[W], F.Identity[SG.Semigroup[W]]))
 }
 
-func Map[GB ~func() T.Tuple2[B, W], GA ~func() T.Tuple2[A, W], FCT ~func(A) B, W, A, B any](f FCT) func(GA) GB {
+func Map[GB ~func() T.Tuple3[B, W, SG.Semigroup[W]], GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], FCT ~func(A) B, W, A, B any](f FCT) func(GA) GB {
-	return IO.Map[GA, GB](T.Map2(f, F.Identity[W]))
+	return IO.Map[GA, GB](T.Map3(f, F.Identity[W], F.Identity[SG.Semigroup[W]]))
 }
 
-func MonadChain[GB ~func() T.Tuple2[B, W], GA ~func() T.Tuple2[A, W], FCT ~func(A) GB, W, A, B any](s S.Semigroup[W]) func(GA, FCT) GB {
+func MonadChain[GB ~func() T.Tuple3[B, W, SG.Semigroup[W]], GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], FCT ~func(A) GB, W, A, B any](fa GA, f FCT) GB {
-	return func(fa GA, f FCT) GB {
+	return func() T.Tuple3[B, W, SG.Semigroup[W]] {
+		a := fa()
+		b := f(a.F1)()
 
-		return func() T.Tuple2[B, W] {
+		return T.MakeTuple3(b.F1, b.F3.Concat(a.F2, b.F2), b.F3)
-			a := fa()
-			b := f(a.F1)()
-
-			return T.MakeTuple2(b.F1, s.Concat(a.F2, b.F2))
-		}
 	}
 }
 
-func Chain[GB ~func() T.Tuple2[B, W], GA ~func() T.Tuple2[A, W], FCT ~func(A) GB, W, A, B any](s S.Semigroup[W]) func(FCT) func(GA) GB {
+func Chain[GB ~func() T.Tuple3[B, W, SG.Semigroup[W]], GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], FCT ~func(A) GB, W, A, B any](f FCT) func(GA) GB {
-	return F.Curry2(F.Swap(MonadChain[GB, GA, FCT](s)))
+	return F.Bind2nd(MonadChain[GB, GA, FCT, W, A, B], f)
 }
 
-func MonadAp[GB ~func() T.Tuple2[B, W], GAB ~func() T.Tuple2[func(A) B, W], GA ~func() T.Tuple2[A, W], W, A, B any](s S.Semigroup[W]) func(GAB, GA) GB {
+func MonadAp[GB ~func() T.Tuple3[B, W, SG.Semigroup[W]], GAB ~func() T.Tuple3[func(A) B, W, SG.Semigroup[W]], GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], W, A, B any](fab GAB, fa GA) GB {
-	return func(fab GAB, fa GA) GB {
+	return func() T.Tuple3[B, W, SG.Semigroup[W]] {
-		return func() T.Tuple2[B, W] {
+		f := fab()
-			f := fab()
+		a := fa()
-			a := fa()
 
-			return T.MakeTuple2(f.F1(a.F1), s.Concat(f.F2, a.F2))
+		return T.MakeTuple3(f.F1(a.F1), f.F3.Concat(f.F2, a.F2), f.F3)
-		}
 	}
 }
 
-func Ap[GB ~func() T.Tuple2[B, W], GAB ~func() T.Tuple2[func(A) B, W], GA ~func() T.Tuple2[A, W], W, A, B any](s S.Semigroup[W]) func(GA) func(GAB) GB {
+func Ap[GB ~func() T.Tuple3[B, W, SG.Semigroup[W]], GAB ~func() T.Tuple3[func(A) B, W, SG.Semigroup[W]], GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], W, A, B any](ga GA) func(GAB) GB {
-	return F.Curry2(F.Swap(MonadAp[GB, GAB, GA](s)))
+	return F.Bind2nd(MonadAp[GB, GAB, GA], ga)
 }
 
-func MonadChainFirst[GB ~func() T.Tuple2[B, W], GA ~func() T.Tuple2[A, W], FCT ~func(A) GB, W, A, B any](s S.Semigroup[W]) func(GA, FCT) GA {
+func MonadChainFirst[GB ~func() T.Tuple3[B, W, SG.Semigroup[W]], GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], FCT ~func(A) GB, W, A, B any](ma GA, f FCT) GA {
-	chain := MonadChain[GA, GA, func(A) GA](s)
+	return C.MonadChainFirst(
-	return func(ma GA, f FCT) GA {
+		MonadChain[GA, GA, func(A) GA],
-		return chain(ma, func(a A) GA {
+		MonadMap[GA, GB, func(B) A],
-			return MonadMap[GA](f(a), F.Constant1[B](a))
+		ma,
-		})
+		f,
-	}
+	)
 }
 
-func ChainFirst[GB ~func() T.Tuple2[B, W], GA ~func() T.Tuple2[A, W], FCT ~func(A) GB, W, A, B any](s S.Semigroup[W]) func(FCT) func(GA) GA {
+func ChainFirst[GB ~func() T.Tuple3[B, W, SG.Semigroup[W]], GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], FCT ~func(A) GB, W, A, B any](f FCT) func(GA) GA {
-	return F.Curry2(F.Swap(MonadChainFirst[GB, GA, FCT](s)))
+	return C.ChainFirst(
+		Chain[GA, GA, func(A) GA],
+		Map[GA, GB, func(B) A],
+		f,
+	)
 }
 
-func Flatten[GAA ~func() T.Tuple2[GA, W], GA ~func() T.Tuple2[A, W], W, A any](s S.Semigroup[W]) func(GAA) GA {
+func Flatten[GAA ~func() T.Tuple3[GA, W, SG.Semigroup[W]], GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], W, A any](mma GAA) GA {
-	chain := MonadChain[GA, GAA, func(GA) GA](s)
+	return MonadChain[GA, GAA, func(GA) GA](mma, F.Identity[GA])
-	return func(mma GAA) GA {
-		return chain(mma, F.Identity[GA])
-	}
 }
 
-func Execute[GA ~func() T.Tuple2[A, W], W, A any](fa GA) W {
+func Execute[GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], W, A any](fa GA) W {
-	return T.Second(fa())
+	return fa().F2
 }
 
-func Evaluate[GA ~func() T.Tuple2[A, W], W, A any](fa GA) A {
+func Evaluate[GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], W, A any](fa GA) A {
-	return T.First(fa())
+	return fa().F1
 }
 
 // MonadCensor modifies the final accumulator value by applying a function
-func MonadCensor[GA ~func() T.Tuple2[A, W], FCT ~func(W) W, W, A any](fa GA, f FCT) GA {
+func MonadCensor[GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], FCT ~func(W) W, W, A any](fa GA, f FCT) GA {
-	return IO.MonadMap[GA, GA](fa, T.Map2(F.Identity[A], f))
+	return IO.MonadMap[GA, GA](fa, T.Map3(F.Identity[A], f, F.Identity[SG.Semigroup[W]]))
 }
 
 // Censor modifies the final accumulator value by applying a function
-func Censor[GA ~func() T.Tuple2[A, W], FCT ~func(W) W, W, A any](f FCT) func(GA) GA {
+func Censor[GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], FCT ~func(W) W, W, A any](f FCT) func(GA) GA {
-	return IO.Map[GA, GA](T.Map2(F.Identity[A], f))
+	return IO.Map[GA, GA](T.Map3(F.Identity[A], f, F.Identity[SG.Semigroup[W]]))
 }
 
 // MonadListens projects a value from modifications made to the accumulator during an action
-func MonadListens[GA ~func() T.Tuple2[A, W], GAB ~func() T.Tuple2[T.Tuple2[A, B], W], FCT ~func(W) B, W, A, B any](fa GA, f FCT) GAB {
+func MonadListens[GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], GAB ~func() T.Tuple3[T.Tuple2[A, B], W, SG.Semigroup[W]], FCT ~func(W) B, W, A, B any](fa GA, f FCT) GAB {
-	return func() T.Tuple2[T.Tuple2[A, B], W] {
+	return func() T.Tuple3[T.Tuple2[A, B], W, SG.Semigroup[W]] {
 		a := fa()
-		return T.MakeTuple2(T.MakeTuple2(a.F1, f(a.F2)), a.F2)
+		return T.MakeTuple3(T.MakeTuple2(a.F1, f(a.F2)), a.F2, a.F3)
 	}
 }
 
 // Listens projects a value from modifications made to the accumulator during an action
-func Listens[GA ~func() T.Tuple2[A, W], GAB ~func() T.Tuple2[T.Tuple2[A, B], W], FCT ~func(W) B, W, A, B any](f FCT) func(GA) GAB {
+func Listens[GA ~func() T.Tuple3[A, W, SG.Semigroup[W]], GAB ~func() T.Tuple3[T.Tuple2[A, B], W, SG.Semigroup[W]], FCT ~func(W) B, W, A, B any](f FCT) func(GA) GAB {
 	return F.Bind2nd(MonadListens[GA, GAB, FCT], f)
 }

writer/testing/laws.go

@@ -37,8 +37,6 @@ func AssertLaws[W, A, B, C any](t *testing.T,
 	bc func(B) C,
 ) func(a A) bool {
 
-	s := M.ToSemigroup(m)
-
 	return L.AssertLaws(t,
 		WRT.Eq(eqw, eqa),
 		WRT.Eq(eqw, eqb),
@@ -60,18 +58,18 @@ func AssertLaws[W, A, B, C any](t *testing.T,
 
 		WRT.MonadMap[func(func(B) C) func(func(A) B) func(A) C, W, func(B) C, func(func(A) B) func(A) C],
 
-		WRT.MonadChain[func(A) WRT.Writer[W, A], W, A, A](m),
+		WRT.MonadChain[func(A) WRT.Writer[W, A], W, A, A],
-		WRT.MonadChain[func(A) WRT.Writer[W, B], W, A, B](m),
+		WRT.MonadChain[func(A) WRT.Writer[W, B], W, A, B],
-		WRT.MonadChain[func(A) WRT.Writer[W, C], W, A, C](m),
+		WRT.MonadChain[func(A) WRT.Writer[W, C], W, A, C],
-		WRT.MonadChain[func(B) WRT.Writer[W, C], W, B, C](m),
+		WRT.MonadChain[func(B) WRT.Writer[W, C], W, B, C],
 
-		WRT.MonadAp[A, A](s),
+		WRT.MonadAp[A, A, W],
-		WRT.MonadAp[B, A](s),
+		WRT.MonadAp[B, A, W],
-		WRT.MonadAp[C, B](s),
+		WRT.MonadAp[C, B, W],
-		WRT.MonadAp[C, A](s),
+		WRT.MonadAp[C, A, W],
 
-		WRT.MonadAp[B, func(A) B](s),
+		WRT.MonadAp[B, func(A) B, W],
-		WRT.MonadAp[func(A) C, func(A) B](s),
+		WRT.MonadAp[func(A) C, func(A) B, W],
 
 		ab,
 		bc,

writer/writer.go

@@ -24,7 +24,7 @@ import (
 	G "github.com/IBM/fp-go/writer/generic"
 )
 
-type Writer[W, A any] IO.IO[T.Tuple2[A, W]]
+type Writer[W, A any] IO.IO[T.Tuple3[A, W, S.Semigroup[W]]]
 
 func Of[A, W any](m M.Monoid[W]) func(A) Writer[W, A] {
 	return G.Of[Writer[W, A]](m)
@@ -48,32 +48,32 @@ func Map[W any, FCT ~func(A) B, A, B any](f FCT) func(Writer[W, A]) Writer[W, B]
 	return G.Map[Writer[W, B], Writer[W, A]](f)
 }
 
-func MonadChain[FCT ~func(A) Writer[W, B], W, A, B any](s S.Semigroup[W]) func(Writer[W, A], FCT) Writer[W, B] {
+func MonadChain[FCT ~func(A) Writer[W, B], W, A, B any](fa Writer[W, A], fct FCT) Writer[W, B] {
-	return G.MonadChain[Writer[W, B], Writer[W, A], FCT](s)
+	return G.MonadChain[Writer[W, B], Writer[W, A], FCT](fa, fct)
 }
 
-func Chain[A, B, W any](s S.Semigroup[W]) func(func(A) Writer[W, B]) func(Writer[W, A]) Writer[W, B] {
+func Chain[A, B, W any](fa func(A) Writer[W, B]) func(Writer[W, A]) Writer[W, B] {
-	return G.Chain[Writer[W, B], Writer[W, A], func(A) Writer[W, B]](s)
+	return G.Chain[Writer[W, B], Writer[W, A], func(A) Writer[W, B]](fa)
 }
 
-func MonadAp[B, A, W any](s S.Semigroup[W]) func(Writer[W, func(A) B], Writer[W, A]) Writer[W, B] {
+func MonadAp[B, A, W any](fab Writer[W, func(A) B], fa Writer[W, A]) Writer[W, B] {
-	return G.MonadAp[Writer[W, B], Writer[W, func(A) B], Writer[W, A]](s)
+	return G.MonadAp[Writer[W, B], Writer[W, func(A) B], Writer[W, A]](fab, fa)
 }
 
-func Ap[B, A, W any](s S.Semigroup[W]) func(Writer[W, A]) func(Writer[W, func(A) B]) Writer[W, B] {
+func Ap[B, A, W any](fa Writer[W, A]) func(Writer[W, func(A) B]) Writer[W, B] {
-	return G.Ap[Writer[W, B], Writer[W, func(A) B], Writer[W, A]](s)
+	return G.Ap[Writer[W, B], Writer[W, func(A) B], Writer[W, A]](fa)
 }
 
-func MonadChainFirst[FCT ~func(A) Writer[W, B], W, A, B any](s S.Semigroup[W]) func(Writer[W, A], FCT) Writer[W, A] {
+func MonadChainFirst[FCT ~func(A) Writer[W, B], W, A, B any](fa Writer[W, A], fct FCT) Writer[W, A] {
-	return G.MonadChainFirst[Writer[W, B], Writer[W, A], FCT](s)
+	return G.MonadChainFirst[Writer[W, B], Writer[W, A], FCT](fa, fct)
 }
 
-func ChainFirst[FCT ~func(A) Writer[W, B], W, A, B any](s S.Semigroup[W]) func(FCT) func(Writer[W, A]) Writer[W, A] {
+func ChainFirst[FCT ~func(A) Writer[W, B], W, A, B any](fct FCT) func(Writer[W, A]) Writer[W, A] {
-	return G.ChainFirst[Writer[W, B], Writer[W, A], FCT](s)
+	return G.ChainFirst[Writer[W, B], Writer[W, A], FCT](fct)
 }
 
-func Flatten[W, A any](s S.Semigroup[W]) func(Writer[W, Writer[W, A]]) Writer[W, A] {
+func Flatten[W, A any](mma Writer[W, Writer[W, A]]) Writer[W, A] {
-	return G.Flatten[Writer[W, Writer[W, A]], Writer[W, A]](s)
+	return G.Flatten[Writer[W, Writer[W, A]], Writer[W, A]](mma)
 }
 
 // Execute extracts the accumulator

writer/writer_test.go

@@ -20,30 +20,28 @@ import (
 
 	A "github.com/IBM/fp-go/array"
 	F "github.com/IBM/fp-go/function"
-	M "github.com/IBM/fp-go/monoid"
+	S "github.com/IBM/fp-go/semigroup"
 	T "github.com/IBM/fp-go/tuple"
 )
 
 func doubleAndLog(data int) Writer[[]string, int] {
-	return func() T.Tuple2[int, []string] {
+	return func() T.Tuple3[int, []string, S.Semigroup[[]string]] {
 		result := data * 2
-		return T.MakeTuple2(result, A.Of(fmt.Sprintf("Doubled %d -> %d", data, result)))
+		return T.MakeTuple3(result, A.Of(fmt.Sprintf("Doubled %d -> %d", data, result)), sg)
 	}
 }
 
 func ExampleWriter_logging() {
 
-	m := A.Monoid[string]()
+	res := F.Pipe4(
-	s := M.ToSemigroup(m)
-
-	res := F.Pipe3(
 		10,
-		Of[int](m),
+		Of[int](monoid),
-		Chain[int, int](s)(doubleAndLog),
+		Chain(doubleAndLog),
-		Chain[int, int](s)(doubleAndLog),
+		Chain(doubleAndLog),
+		Execute[[]string, int],
 	)
 
-	fmt.Println(res())
+	fmt.Println(res)
 
-	// Output: Tuple2[int, []string](40, [Doubled 10 -> 20 Doubled 20 -> 40])
+	// Output: [Doubled 10 -> 20 Doubled 20 -> 40]
 }