Re: [Ocaml-lib-devel] Suggestion for a new module

[Nicolas C. <war...@fr...>]

> > Dear Ext-lib developers,
> >
> > This tiny module:
> > http://www.eleves.ens.fr/home/frisch/soft.html#memo
> >
> > implements memoization tables with bounded size. Such a table can be
> > used to memoize a function without using a lot of memory. A hash
> > function is used to retrieve a previously computed value for a given
> > key. The implementation uses a nice and simple heuristic to choose what
> > to do in case of collision on the hash value for two keys.
> >
> > Feel free to add this module to ext-lib if you think it can be useful.
>
> On a related topic: the Hashtbl module
> Would it be a good thing to add functions which do not require to
> recompute the hashed key (with Hashtbl.hash), for efficiency purposes:
>
> val unsafe_find : ('key, 'data) t -> int -> 'key -> 'data
> val unsafe_mem : ('key, 'data) t -> int -> 'key -> bool
> val unsafe_add : ('key, 'data) t -> int -> 'key -> 'data -> unit

This require a lot of "unsafe" functions, and actually they are not "unsafe"
at all :)
The best way to enforce that is to use a (int,'a) Hashtbl.t and hash your
values by hand when needed.

Nicolas