Module type MoreLabels.Hashtbl.HashedType
Module type HashedType
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).