Rename MapMap and new map func

Renamed MapMap to MapSameKeys to increase clarity for usage
Added func MapNewKeys to allow making a map with new keys too

maputils/mapUtils.go

@@ -2,9 +2,10 @@ package maputils
 
 import "gitlab.com/mstarongitlab/goutils/sliceutils"
 
-// MapMap applies a given function to every key-value pair of a map.
+// MapSameKeys applies a given function to every key-value pair of a map.
-// The returned map's value type may be different from the type of the inital map's value.
+// The returned map's value type may be different from the type of the inital map's value
-func MapMap[K comparable, V any, R any](dic map[K]V, apply func(K, V) R) map[K]R {
+// But it will keep the same keys as the input map
+func MapSameKeys[K comparable, V any, R any](dic map[K]V, apply func(K, V) R) map[K]R {
 	n := make(map[K]R, len(dic))
 	for key, val := range dic {
 		n[key] = apply(key, val)
@@ -12,6 +13,21 @@ func MapMap[K comparable, V any, R any](dic map[K]V, apply func(K, V) R) map[K]R
 	return n
 }
 
+// MapNewKeys applies a given function to every key-value pair of a map.
+// The returned map's keys and values may be of different types as the input map
+// The first return value of the apply func will be used as new key, the second as the value
+func MapNewKeys[Kin comparable, Vin any, Kout comparable, Vout any](
+	in map[Kin]Vin,
+	apply func(Kin, Vin) (Kout, Vout),
+) map[Kout]Vout {
+	n := make(map[Kout]Vout, len(in))
+	for ki, vi := range in {
+		ko, vo := apply(ki, vi)
+		n[ko] = vo
+	}
+	return n
+}
+
 // FilterMap filters a map using a given function.
 // If the filter function returns true, the key-value pair stays, otherwise it gets removed.
 func FilterMap[K comparable, V any](dic map[K]V, filter func(K, V) bool) map[K]V {