fix: add WithTempFile to ReaderIOEither

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

context/readerioeither/file/file.go

@@ -25,6 +25,7 @@ import (
 	F "github.com/IBM/fp-go/function"
 	"github.com/IBM/fp-go/internal/file"
 	IOE "github.com/IBM/fp-go/ioeither"
+	IOEF "github.com/IBM/fp-go/ioeither/file"
 )
 
 var (
@@ -35,6 +36,12 @@ var (
 		RIOE.FromIOEither[*os.File],
 		RIOE.WithContext[*os.File],
 	)
+
+	// Remove removes a file by name
+	Remove = F.Flow2(
+		IOEF.Remove,
+		RIOE.FromIOEither[string],
+	)
 )
 
 // Close closes an object

context/readerioeither/file/tempfile.go

@@ -0,0 +1,53 @@
+// 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 file
+
+import (
+	"os"
+
+	RIOE "github.com/IBM/fp-go/context/readerioeither"
+	FL "github.com/IBM/fp-go/file"
+	F "github.com/IBM/fp-go/function"
+	IO "github.com/IBM/fp-go/io"
+	IOF "github.com/IBM/fp-go/io/file"
+	IOEF "github.com/IBM/fp-go/ioeither/file"
+)
+
+var (
+	// onCreateTempFile creates a temp file with sensible defaults
+	onCreateTempFile = CreateTemp("", "*")
+	// destroy handler
+	onReleaseTempFile = F.Flow4(
+		IOF.Close[*os.File],
+		IO.Map(FL.GetName),
+		RIOE.FromIO[string],
+		RIOE.Chain(Remove),
+	)
+)
+
+// CreateTemp created a temp file with proper parametrization
+func CreateTemp(dir, pattern string) RIOE.ReaderIOEither[*os.File] {
+	return F.Pipe2(
+		IOEF.CreateTemp(dir, pattern),
+		RIOE.FromIOEither[*os.File],
+		RIOE.WithContext[*os.File],
+	)
+}
+
+// WithTempFile creates a temporary file, then invokes a callback to create a resource based on the file, then close and remove the temp file
+func WithTempFile[A any](f func(*os.File) RIOE.ReaderIOEither[A]) RIOE.ReaderIOEither[A] {
+	return RIOE.WithResource[A](onCreateTempFile, onReleaseTempFile)(f)
+}

context/readerioeither/generic/reader.go

@@ -100,6 +100,28 @@ func Map[
 	return RIE.Map[GRA, GRB](f)
 }
 
+func MonadMapTo[
+	GRA ~func(context.Context) GIOA,
+	GRB ~func(context.Context) GIOB,
+
+	GIOA ~func() E.Either[error, A],
+	GIOB ~func() E.Either[error, B],
+
+	A, B any](fa GRA, b B) GRB {
+	return RIE.MonadMapTo[GRA, GRB](fa, b)
+}
+
+func MapTo[
+	GRA ~func(context.Context) GIOA,
+	GRB ~func(context.Context) GIOB,
+
+	GIOA ~func() E.Either[error, A],
+	GIOB ~func() E.Either[error, B],
+
+	A, B any](b B) func(GRA) GRB {
+	return RIE.MapTo[GRA, GRB](b)
+}
+
 func MonadChain[
 	GRA ~func(context.Context) GIOA,
 	GRB ~func(context.Context) GIOB,

context/readerioeither/reader.go

@@ -61,6 +61,14 @@ func Map[A, B any](f func(A) B) func(ReaderIOEither[A]) ReaderIOEither[B] {
 	return G.Map[ReaderIOEither[A], ReaderIOEither[B]](f)
 }
 
+func MonadMapTo[A, B any](fa ReaderIOEither[A], b B) ReaderIOEither[B] {
+	return G.MonadMapTo[ReaderIOEither[A], ReaderIOEither[B]](fa, b)
+}
+
+func MapTo[A, B any](b B) func(ReaderIOEither[A]) ReaderIOEither[B] {
+	return G.MapTo[ReaderIOEither[A], ReaderIOEither[B]](b)
+}
+
 func MonadChain[A, B any](ma ReaderIOEither[A], f func(A) ReaderIOEither[B]) ReaderIOEither[B] {
 	return G.MonadChain(ma, f)
 }

either/exec/exec.go

@@ -27,7 +27,7 @@ import (
 var (
 	// Command executes a command
 	// use this version if the command does not produce any side effect, i.e. if the output is uniquely determined by by the input
-	// typically you'd rather use the IOEither version of the command
+	// typically you'd rather use the [IOEither] version of the command
 	Command = F.Curry3(command)
 )
 

exec/exec.go

@@ -20,11 +20,14 @@ import (
 )
 
 type (
-	// command output
+	// CommandOutput represents the output of executing a command. The first field in the [Tuple2] is
+	// stdout, the second one is stderr. Use [StdOut] and [StdErr] to access these fields
 	CommandOutput = T.Tuple2[[]byte, []byte]
 )
 
 var (
+	// StdOut returns the field of a [CommandOutput] representing `stdout`
 	StdOut = T.First[[]byte, []byte]
+	// StdErr returns the field of a [CommandOutput] representing `stderr`
 	StdErr = T.Second[[]byte, []byte]
 )