Add presentation to sample section (#76)

* doc: add presentation Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> * fix: add some more examples Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> * doc: update presentation Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> * fix: update presentation Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> * fix: add presentation and samples Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> * fix: benchmarks Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> * fix: upload presentation Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> * doc: add presentation Signed-off-by: Carsten Leue <carsten.leue@de.ibm.com> * doc: add link to video Signed-off-by: Carsten Leue <carsten.leue@de.ibm.com> --------- Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com> Signed-off-by: Carsten Leue <carsten.leue@de.ibm.com>
2025-08-10 22:31:32 +02:00 · 2023-11-08 09:58:23 +01:00
parent 57d507c1ba
commit d43fbeb375
23 changed files with 1036 additions and 13 deletions
--- a/samples/presentation/examples/example_either_test.go
+++ b/samples/presentation/examples/example_either_test.go
@@ -0,0 +1,103 @@
+// 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 examples
+
+import (
+	"fmt"
+	"strconv"
+
+	E "github.com/IBM/fp-go/either"
+	F "github.com/IBM/fp-go/function"
+	S "github.com/IBM/fp-go/string"
+)
+
+func validatePort(port int) (int, error) {
+	if port > 0 {
+		return port, nil
+	}
+	return 0, fmt.Errorf("Value %d is not a valid port number", port)
+}
+
+func Example_either_monad() {
+
+	// func(string) E.Either[error, int]
+	atoi := E.Eitherize1(strconv.Atoi)
+	// func(int) E.Either[error, int]
+	valPort := E.Eitherize1(validatePort)
+
+	// func(string) E.Either[error, string]
+	makeUrl := F.Flow3(
+		atoi,
+		E.Chain(valPort),
+		E.Map[error](S.Format[int]("http://localhost:%d")),
+	)
+
+	fmt.Println(makeUrl("8080"))
+
+	// Output:
+	// Right[<nil>, string](http://localhost:8080)
+}
+
+func Example_either_idiomatic() {
+
+	makeUrl := func(port string) (string, error) {
+		parsed, err := strconv.Atoi(port)
+		if err != nil {
+			return "", err
+		}
+		valid, err := validatePort(parsed)
+		if err != nil {
+			return "", err
+		}
+		return fmt.Sprintf("http://localhost:%d", valid), nil
+	}
+
+	url, err := makeUrl("8080")
+	if err != nil {
+		panic(err)
+	}
+	fmt.Println(url)
+
+	// Output:
+	// http://localhost:8080
+}
+
+func Example_either_worlds() {
+
+	// func(string) E.Either[error, int]
+	atoi := E.Eitherize1(strconv.Atoi)
+	// func(int) E.Either[error, int]
+	valPort := E.Eitherize1(validatePort)
+
+	// func(string) E.Either[error, string]
+	makeUrl := F.Flow3(
+		atoi,
+		E.Chain(valPort),
+		E.Map[error](S.Format[int]("http://localhost:%d")),
+	)
+
+	// func(string) (string, error)
+	makeUrlGo := E.Uneitherize1(makeUrl)
+
+	url, err := makeUrlGo("8080")
+	if err != nil {
+		panic(err)
+	}
+	fmt.Println(url)
+
+	// Output:
+	// http://localhost:8080
+}