:kind feature request in ghci

Simon Peyton-Jones simonpj at microsoft.com
Mon Apr 5 13:10:07 EDT 2004


Done!  In the HEAD anyway, and will therefore be in 6.4

Simon

Prelude> :k Int
Int :: *
Prelude> :k Maybe
Maybe :: * -> *
Prelude> :k Maybe Int
Maybe Int :: *
Prelude> :q

| -----Original Message-----
| From: glasgow-haskell-users-bounces at haskell.org
[mailto:glasgow-haskell-users-
| bounces at haskell.org] On Behalf Of S. Alexander Jacobson
| Sent: 27 March 2004 15:33
| To: GHC users
| Subject: :kind feature request in ghci
| 
| I keep running into kind errors (see my most
| recent post on Haskell cafe).  Would it be
| possible for ghci to expose a :kind function
| that operates on types the way :type operates on
| values?
| 
| Alternatively, is there another way to
| figure out how to create an instance of
| a class like this?
| 
|     class MyClass a b where emptyVal::a b
| 
| Here are one of the thing that don't work:
| 
|     type MyType a = [a]
|     instance MyClass (MyType a) a where emptyVal=[]
| 
| And I have no idea why...
| 
| -Alex-
| 
| _________________________________________________________________
| S. Alexander Jacobson                  mailto:me at alexjacobson.com
| tel:917-770-6565                       http://alexjacobson.com
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