first-commit

modules/container/filter.go

@@ -0,0 +1,21 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package container
+
+import "slices"
+
+// FilterSlice ranges over the slice and calls include() for each element.
+// If the second returned value is true, the first returned value will be included in the resulting
+// slice (after deduplication).
+func FilterSlice[E any, T comparable](s []E, include func(E) (T, bool)) []T {
+	filtered := make([]T, 0, len(s)) // slice will be clipped before returning
+	seen := make(map[T]bool, len(s))
+	for i := range s {
+		if v, ok := include(s[i]); ok && !seen[v] {
+			filtered = append(filtered, v)
+			seen[v] = true
+		}
+	}
+	return slices.Clip(filtered)
+}