deriving...

MR K P SCHUPKE k.schupke at imperial.ac.uk
Wed Oct 13 09:05:56 EDT 2004


What is the situation with deriving?

Some instances can be derived automatically for both data/newtype (built in)?

Some instances cen be derived automatically for newtype (any)?

You used to be able to define functions useing {|+|} and {|*|} (or similar)
that could be derived for both data and newtype.

What is the current status, which methods are supported, and will be
supported going forward.

I ask this because looking at the code in the compiler it seems very
difficault to extend. It would be to specify how to derive new instances
once and for all...

	Keean.


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