Re: Mutually recursive modules and derived instances of Data

On Wed, 13 Oct 2004 13:21:26 +0100, Simon Peyton-Jones wrote:

1. Separate 'deriving' from the data type decl, so you can say derive( Data TA, Typeable TA ) anywhere. People sometimes ask for this for other reasons.

2. Allow instances in hi-boot files

You might say "both would be useful", but I'd be interested in people's opinions about which of (1) or (2) would be preferable if you could only have one or t'other.

1! As you say, people sometimes ask for this for other reasons. I'm one of them, though I'm not sure if I've actually asked about it on the list. Separating deriving from the declaration would be incredibly useful. /Martin