module type HashedType = Hashtbl.HashedType
type t
The type of the hashtable keys.
val equal : t -> t -> bool
The equality predicate used to compare keys.
val hash : t -> int
A hashing function on keys. It must be such that if two keys are equal according to equal
, then they have identical hash values as computed by hash
. Examples: suitable (equal
, hash
) pairs for arbitrary key types include
(=)
, Hashtbl.hash
) for comparing objects by structure (provided objects do not contain floats)(fun x y -> compare x y = 0)
, Hashtbl.hash
) for comparing objects by structure and handling nan
correctly(==)
, Hashtbl.hash
) for comparing objects by physical equality (e.g. for mutable or cyclic objects).