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Changes between Version 4 and Version 5 of GhcKinds/KindsWithoutData

v4	v5
47	47
48	48
49		= ~~Notes~~ =
	49	= Defining datatypes without an associated kind =
50	50
51		* `data kind K ...`
	51	By extension, we might want to define a datatype that will never be promoted, even with `-XDataKinds`.
	52	For that we propose the syntax `data type D ...`.
52	53
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
	56	Currently GHC does not promote type synonyms. We propose to change this, and make GHC promote
	57	type synonyms to kind synonyms by default with `-XDataKinds`. For instance, `type String = [Char]`
	58	should give rise to a kind `String`.
	59
	60	'''Question:''' are there dangerous interactions with `-XLiberalTypeSynonyms`? E.g. what's the kind
	61	of ''type K a = forall b. b -> a`?
	62
	63	By extension, we might want to have kind synonyms that do not arise from promotion: `type kind K ...`.
	64	And perhaps even type synonyms that never give rise to a promoted kind: `type type T ...`.