Re: [Ocaml-lib-devel] Re: Re: Doubly LinkedList module, or Ordered Hashtbl module?

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

> >> Do you want me to slap together an OrdHashtbl module? Or do you want to
> >> finish it off yourself based on the work you posted to the beginners
list
> >> earlier today?
> >
> > IMHO, the ordered hashtable idea is too specialized for inclusion in the
> > standard library.  Generally, depending upon what order internally a
> > hashtable stores it's entries is a bad idea.
>
> Why is it a bad idea?
>
> I need to create a Hashtbl based on a file. I'd like to be able to write
> the file back out to disk in the same order I read it in. What's wrong
> with that? I'm sure there are other applications as well.

What you need then is not an ordered Hashtbl since your keys will not keep
your file ordered.
If I were you I would store the pair (keys,values) in an DynArray and build
an Hashtbl so I can retreive the index of the value in the array using only
the key. Only a list or an array can keep correctly the order you want.

Nicolas