[Hugs-users] Network.CGI missing in Hugs

Ross Paterson ross at soi.city.ac.uk
Fri Jan 5 12:04:15 EST 2007


On Fri, Jan 05, 2007 at 03:51:31PM +0100, Sven Panne wrote:
> I've tested the new cgi package a few days ago and IIRC there were basically 
> two problems:
> 
>    * Hugs doesn't support System.Environment.getEnvironment yet, but I guess 
> that this could easily be fixed.

Indeed.
 
>    * Some instances in Network.CGI.Monad overlap, which is not supported in 
> Hugs. I don't know if the overlap is crucial and what the rationale behind 
> this is. Perhaps I've missed some discussions on the libraries list. Perhaps 
> we can simply #ifdef/remove the overlap. Ross?

One could expand MonadTrans in

	instance (MonadTrans t, MonadCGI m, Monad (t m)) => MonadCGI (t m)

replacing it with

	instance (MonadCGI m) => MonadCGI (ListT m)
	instance (MonadCGI m) => MonadCGI (ContT m)
	instance (Error e, MonadCGI m) => MonadCGI (ErrorT e m)
	instance (MonadCGI m) => MonadCGI (ReaderT r m)
	instance (MonadCGI m) => MonadCGI (StateT s m)
	instance (Monoid w, MonadCGI m) => MonadCGI (StateT w m)
	instance (Monoid w, MonadCGI m) => MonadCGI (RWST r w s m)



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