Crytpo for nhc

[Dominic Steinitz]

Malcolm,

Thanks for this. I'm restructuring the Crypto libraries so that it will
contain Crypto.Modes, Crypto.DES, Crypto.Blowfish etc. The current Blowfish
should work with nhc. When I get the chance, I'll see if I can restructure
DES but it's not top of my priorities at the moment.

[Dominic Steinitz
----- Original Message -----
From: "Malcolm Wallace" <Malcolm.Wallace@cs.york.ac.uk>
To: "Dominic Steinitz" <dominic.steinitz@blueyonder.co.uk>
Cc: <nhc-users@haskell.org>; <libraries@haskell.org>
Sent: Tuesday, April 29, 2003 2:33 PM
Subject: Re: Crytpo for nhc


> "Dominic Steinitz" <dominic.steinitz@blueyonder.co.uk> writes:
>
> > I have been trying to write a Crypto library and so far it works with
ghc
> > and hugs.
> >
> > Am I right in thinking I am going to struggle with nhc? It uses Word8
and
> > Word64 heavily. For example, cipher block chaining relies on xoring
Word64.
>
> The things you mention are not a particular problem for nhc98.
> The only problem I encountered in the Crypto.hs code is that its use
> of the type class machinery is not Haskell'98 compliant.
>
>     instance Bits [Bool] where ...
>
> is illegal in Haskell'98, because an instance head must be either a
> simple type name, or a type constructor applied to only type variables.
> (See the Report section 4.3.2)  If ghc and Hugs permit this, then it is
> a non-standard extension to the language.
>
> Unfortunately, I don't immediately see an easy way to convert this
> construction into something more amenable.
>
> Regards,
>     Malcolm