Added FilterMap

moslice/filter.go

@@ -16,3 +16,22 @@ func Filter[T any](ts []T, predicate func(t T) bool) []T {
 	}
 	return filteredTs
 }
+
+// FilterMap returns a mapped slice containing all the elements of ts for which the passed in
+// predicate returns true.  If no items match the predicate, the function will return
+// an empty slice.  If ts is nil, the function will also return nil.
+func FilterMap[T, U any](ts []T, predicate func(t T) (U, bool)) []U {
+	if ts == nil {
+		return nil
+	}
+
+	filteredUs := make([]U, 0)
+	for _, t := range ts {
+		u, ok := predicate(t)
+		if !ok {
+			continue
+		}
+		filteredUs = append(filteredUs, u)
+	}
+	return filteredUs
+}