val doesnt_exist : t -> 'adoesnt_exist path raises the Doesnt_exist exception
val getdomainpath : int -> tgetdomainpath domid returns the default directory for domid
create path default is the absolute path of path, where if path is relative then it is resolved relative to default
val to_string : t -> stringto_string t returns t as a '/'-separated path string
val to_string_list : t -> string listto_string_list t returns t as a list of path element strings
val of_string_list : string list -> tof_string_list l returns l as an instance of type t
get_common_prefix a b returns the largest common prefix of a and b
get_parent t returns the parent node of t. The parent of the root node is itself.