Proposal: ExplicitForall

Simon Peyton-Jones simonpj at microsoft.com
Wed Jun 24 04:09:52 EDT 2009


| I would thus like to propose the following formalisation of the
| ExplicitForall extension:

What you suggest would be fine with me. Presumably ExplicitForall would be implied by RankNTypes and the other extensions?

There is a danger of having too *many* choices. (http://www.joelonsoftware.com/items/2006/11/21.html)  In particular, you might consider making ScopedTypeVariables synonymous with ExplicitForAll.  Once you have given up the keyword, it seems a shame not to allow lexically scoped type variables!  

On ExistentialQuantification, I personally think we should deprecate the entire construct, suggesting GADT-style syntax instead.

If you can form a consensus, go for it.

Simon



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