val is_empty : 'a t -> bool
val add : 'a t -> string -> 'a -> [ `New of 'a t | `Replaced of 'a * 'a t ]
val find :
legacy_prefixes:bool ->
'a t ->
string ->
('a, [ `Ambiguous | `Not_found ]) Stdlib.result
val ambiguities : 'a t -> string -> string list
val of_list : (string * 'a) list -> 'a t
val legacy_prefixes : env:(string -> string option) -> bool