Hash.Ftype state = Hash.statetype seed = Hash.seedval alloc : unit -> statetype hash_value = Hash.hash_valueval get_hash_value : state -> hash_valuemodule For_tests : sig ... endval of_fold : (state -> 'a -> state) -> 'a -> hash_valuemodule Builtin : sig ... endval run : ?seed:seed -> 'a folder -> 'a -> hash_value