The input signature of the functor
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
Examples: suitable (
hash ) pairs for arbitrary key
Hashtbl.hash ) for comparing objects by structure
(provided objects do not contain floats)
(fun x y -> compare x y = 0) ,
for comparing objects by structure
Hashtbl.hash ) for comparing objects by physical
equality (e.g. for mutable or cyclic objects).