refactor variable system to be the responsibility of effect enforcer.

internal/gentools/maps.go

@@ -14,3 +14,12 @@ func OneItemMap[K comparable, V any](key K, value V) map[K]V {
 	m[key] = value
 	return m
 }
+
+func MapKeys[K comparable, V any](m map[K]V) []K {
+	keys := make([]K, 0, len(m))
+	for key := range m {
+		keys = append(keys, key)
+	}
+
+	return keys
+}