NAME

       Hashtbl.HashedType - The input signature of the functor Hashtbl.Make.

Module type

       Module type   Hashtbl.HashedType

Documentation

       Module type HashedType
        = sig end

       The input signature of the functor Hashtbl.Make .

       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.HashedType.hash ) for comparing objects by structure (provided
       objects do not contain floats)

       -        ( (fun x y -> compare x y = 0) , Hashtbl.HashedType.hash ) for comparing  objects
       by structure and handling nan correctly

       -         (  (==)  ,  Hashtbl.HashedType.hash ) for comparing objects by physical equality
       (e.g. for mutable or cyclic objects).