Hashtbl.HashedType

Section: OCaml library (3)
Updated: 2009-07-27
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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.hash ) for comparing objects by structure, ( (fun x y -> compare x y = 0) , Hashtbl.hash ) for comparing objects by structure and handling Pervasives.nan correctly, and ( (==) , Hashtbl.hash ) for comparing objects by addresses (e.g. for cyclic keys).