forester.prelude
Forester_prelude.Option_util
forester.compiler
forester.core
forester.frontend
forester.human_datetime
forester.language_server
forester.parser
forester.search
forester.server
forester.test
forester.xml_names
val override : 'a option -> 'a option -> 'a option
val guard : ('a -> bool) -> 'a -> 'a option