Proposal: Deprecate ExistentialQuantification

Wolfgang Jeltsch g9ks157k at
Fri Jul 10 05:03:00 EDT 2009

Am Samstag, 27. Juni 2009 12:44 schrieb Niklas Broberg:
> Hi all,
> Following the discussion on the use of 'forall' and extensions that
> use it [1], I would hereby like to propose that the
> ExistentialQuantification extension is deprecated.
> My rationale is as follows. With the introduction of GADTs, we now
> have two ways to write datatype declarations, the old simple way and
> the GADTs way.

Isn’t ExistentialQuantification more powerful than using GADTs for emulating 
existential quantification? To my knowledge, it is possible to use lazy 
patterns with existential types but not with GADTs.

Best wishes,

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