initial

1 files changed, 27 insertions, 0 deletions

diff --git a/map.go b/map.go
new file mode 100644
index 0000000..065a6a6
--- /dev/null
+++ b/map.go
@@ -0,0 +1,27 @@
+package collection
+
+import "sync"
+
+func MapSync[T any, R any](collection []T, cb func(item T, idx int) R) []R {
+	result := make([]R, len(collection))
+	for i, v := range collection {
+		result[i] = cb(v, i)
+	}
+	return result
+}
+
+func Map[T any, R any](collection []T, cb func(item T, idx int) R) []R {
+	result := make([]R, len(collection))
+	wg := sync.WaitGroup{}
+	wg.Add(len(collection))
+	for i, v := range collection {
+		func(v T, i int) {
+			go func() {
+				defer wg.Done()
+				result[i] = cb(v, i)
+			}()
+		}(v, i)
+	}
+	wg.Wait()
+	return result
+}