Changes between Version 4 and Version 5 of GhcKinds/KindsWithoutData


Ignore:
Timestamp:
Jun 27, 2012 1:43:32 PM (22 months ago)
Author:
dreixel
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • GhcKinds/KindsWithoutData

    v4 v5  
    4747 
    4848 
    49 = Notes = 
     49= Defining datatypes without an associated kind = 
    5050 
    51  * `data kind K ...` 
     51By extension, we might want to define a datatype that will never be promoted, even with `-XDataKinds`. 
     52For that we propose the syntax `data type D ...`. 
    5253 
    53  * Allow `*` on `data kind`s? Or maybe `Type`, or `Star`. 
    54   
    55  * Perhaps also `data type D ...` 
    56   
    57  * Promote type synonyms by default 
    58   
    59  * What about `type kind K1 = K2`? 
    60   
    61  * Even worse: `type type T1 = T2`... 
     54= Kind synonyms (from type synonym promotion) = 
     55 
     56Currently GHC does not promote type synonyms. We propose to change this, and make GHC promote 
     57type synonyms to kind synonyms by default with `-XDataKinds`. For instance, `type String = [Char]` 
     58should give rise to a kind `String`. 
     59 
     60'''Question:''' are there dangerous interactions with `-XLiberalTypeSynonyms`? E.g. what's the kind 
     61of ''type K a = forall b. b -> a`? 
     62 
     63By extension, we might want to have kind synonyms that do not arise from promotion: `type kind K ...`. 
     64And perhaps even type synonyms that never give rise to a promoted kind: `type type T ...`.