Hello, I think that it'd be really useful to be able to just declare a `kind` without having to promote a datatype. When we discussed this last time (summarized by the link Pedro sent, I think) it came up that it might be nice to also have kind synonyms, which would be analogous to type synonyms, but one level up. The "natural" syntax for that would be to have a "type kind" declaration, but this seems a bit confusing... John, did you implement kind synonyms in jhc, and if so what syntax did you use? -Iavor On Sat, Jan 26, 2013 at 6:11 PM, John Meacham wrote:

On Fri, Jan 25, 2013 at 7:19 AM, Ross Paterson wrote:

...

GHC implements data kinds by promoting data declarations of a certain restricted form, but I wonder if it would be better to have a special syntax for kind definitions, say

data kind Nat = Zero | Succ Nat

This is exactly the syntax jhc uses for user defined kinds.

John

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This has the problem that kind is currently a valid function name, so it would take a new keyword, or at least on conditional on the DataKinds extension. -Edward On Sun, Jan 27, 2013 at 3:02 AM, Erik Hesselink wrote:

When we discussed this last time (summarized by the link Pedro sent, I

...

think) it came up that it might be nice to also have kind synonyms, which would be analogous to type synonyms, but one level up. The "natural" syntax for that would be to have a "type kind" declaration, but this seems a bit confusing...

What about just 'kind'? It's symmetric with 'type'.

Erik

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