first commit

maps/base.go

@@ -0,0 +1,38 @@
+package maps
+
+import "maps"
+
+// InitMap initializes a map pointer if it is nil.
+// If the map is already initialized, this function does nothing.
+//
+// This is useful for ensuring a map is ready to use before adding entries,
+// preventing nil pointer dereferences.
+//
+// Example:
+//
+//	var m map[string]int
+//	InitMap(&m)
+//	m["key"] = 42 // safe to use
+func InitMap[K comparable, V any, T ~map[K]V](m *T) {
+	if *m == nil {
+		*m = make(T)
+	}
+}
+
+// UpdateMap merges entries from the new map into the old map.
+// If the old map is nil, it will be initialized first.
+// Existing keys in the old map will be overwritten with values from the new map.
+//
+// This function modifies the old map in place by copying all key-value pairs
+// from the new map into it.
+//
+// Example:
+//
+//	old := map[string]int{"a": 1, "b": 2}
+//	new := map[string]int{"b": 3, "c": 4}
+//	UpdateMap(&old, new)
+//	// old is now: {"a": 1, "b": 3, "c": 4}
+func UpdateMap[K comparable, V any, T ~map[K]V](oldMap *T, newMap T) {
+	InitMap(oldMap)
+	maps.Copy(*oldMap, newMap)
+}