monads

commit 38d7ba562e6504dabcb4566bc898bb8104ee9323
parent d86519fe954cbeef88ccd1c96f611aeb908389d9
Author: Yongbin Kim <iam@yongbin.kim>
Date:   Mon, 10 Oct 2022 08:38:53 +0900

slices: Added MapWithError func

Signed-off-by: Yongbin Kim <iam@yongbin.kim>

Diffstat:
M
slices/map.go
 | 
23
+++++++++++++++++++++++

1 file changed, 23 insertions(+), 0 deletions(-)
diff --git a/slices/map.go b/slices/map.go
@@ -8,6 +8,17 @@ func Map[T any, R any](m []T, action func(T) R) (result []R) {
 	return
 }
 
+func MapWithError[T any, R any](m []T, action func(T) (R, error)) (result []R, err error) {
+	result = make([]R, len(m))
+	for i, item := range m {
+		result[i], err = action(item)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return
+}
+
 func FlatMap[T any, R any](m []T, action func(T) []R) (result []R) {
 	result = make([]R, 0, len(m))
 	for _, item := range m {
@@ -15,3 +26,15 @@ func FlatMap[T any, R any](m []T, action func(T) []R) (result []R) {
 	}
 	return
 }
+
+func FlatMapWithError[T any, R any](m []T, action func(T) ([]R, error)) (result []R, err error) {
+	result = make([]R, 0, len(m))
+	for _, item := range m {
+		items, err := action(item)
+		if err != nil {
+			return nil, err
+		}
+		result = append(result, items...)
+	}
+	return
+}