[Git][ghc/ghc][master] Update kinds in comments in GHC.Core.TyCon
Marge Bot (@marge-bot)
gitlab at gitlab.haskell.org
Tue Feb 7 15:52:31 UTC 2023
Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC
Commits:
5dce04ee by romes at 2023-02-07T10:52:10-05:00
Update kinds in comments in GHC.Core.TyCon
Use `Type` instead of star kind (*)
Fix comment with incorrect kind * to have kind `Constraint`
- - - - -
1 changed file:
- compiler/GHC/Core/TyCon.hs
Changes:
=====================================
compiler/GHC/Core/TyCon.hs
=====================================
@@ -194,7 +194,7 @@ Note [Type synonym families]
* Type synonym families, also known as "type functions", map directly
onto the type functions in FC:
- type family F a :: *
+ type family F a :: Type
type instance F Int = Bool
..etc...
@@ -210,11 +210,11 @@ Note [Type synonym families]
type instance F (F Int) = ... -- BAD!
* Translation of type family decl:
- type family F a :: *
+ type family F a :: Type
translates to
a FamilyTyCon 'F', whose FamTyConFlav is OpenSynFamilyTyCon
- type family G a :: * where
+ type family G a :: Type where
G Int = Bool
G Bool = Char
G a = ()
@@ -229,7 +229,7 @@ Note [Data type families]
See also Note [Wrappers for data instance tycons] in GHC.Types.Id.Make
* Data type families are declared thus
- data family T a :: *
+ data family T a :: Type
data instance T Int = T1 | T2 Bool
Here T is the "family TyCon".
@@ -321,7 +321,7 @@ See also Note [Wrappers for data instance tycons] in GHC.Types.Id.Make
should not think of a data family T as a *type function* at all, not
even an injective one! We can't allow even injective type functions
on the LHS of a type function:
- type family injective G a :: *
+ type family injective G a :: Type
type instance F (G Int) = Bool
is no good, even if G is injective, because consider
type instance G Int = Bool
@@ -572,21 +572,21 @@ Since they are user-callable we must get their type-argument visibility
information right; and that info is in the TyConBinders.
Here is an example:
- data App a b = MkApp (a b) -- App :: forall {k}. (k->*) -> k -> *
+ data App a b = MkApp (a b) -- App :: forall {k}. (k->Type) -> k -> Type
The TyCon has
- tyConTyBinders = [ Named (Bndr (k :: *) Inferred), Anon (k->*), Anon k ]
+ tyConTyBinders = [ Named (Bndr (k :: Type) Inferred), Anon (k->Type), Anon k ]
The TyConBinders for App line up with App's kind, given above.
But the DataCon MkApp has the type
- MkApp :: forall {k} (a:k->*) (b:k). a b -> App k a b
+ MkApp :: forall {k} (a:k->Type) (b:k). a b -> App k a b
That is, its ForAllTyBinders should be
- dataConUnivTyVarBinders = [ Bndr (k:*) Inferred
- , Bndr (a:k->*) Specified
+ dataConUnivTyVarBinders = [ Bndr (k:Type) Inferred
+ , Bndr (a:k->Type) Specified
, Bndr (b:k) Specified ]
So tyConTyVarBinders converts TyCon's TyConBinders into TyVarBinders:
@@ -620,8 +620,8 @@ They fit together like so:
type App a (b :: k) = a b
- tyConBinders = [ Bndr (k::*) (NamedTCB Inferred)
- , Bndr (a:k->*) AnonTCB
+ tyConBinders = [ Bndr (k::Type) (NamedTCB Inferred)
+ , Bndr (a:k->Type) AnonTCB
, Bndr (b:k) AnonTCB ]
Note that there are three binders here, including the
@@ -636,13 +636,13 @@ They fit together like so:
that TyVar may scope over some other part of the TyCon's definition. Eg
type T a = a -> a
we have
- tyConBinders = [ Bndr (a:*) AnonTCB ]
+ tyConBinders = [ Bndr (a:Type) AnonTCB ]
synTcRhs = a -> a
So the 'a' scopes over the synTcRhs
* From the tyConBinders and tyConResKind we can get the tyConKind
E.g for our App example:
- App :: forall k. (k->*) -> k -> *
+ App :: forall k. (k->Type) -> k -> Type
We get a 'forall' in the kind for each NamedTCB, and an arrow
for each AnonTCB
@@ -725,15 +725,15 @@ instance Binary TyConBndrVis where
-- things such as:
--
-- 1) Data declarations: @data Foo = ...@ creates the @Foo@ type constructor of
--- kind @*@
+-- kind @Type@
--
-- 2) Type synonyms: @type Foo = ...@ creates the @Foo@ type constructor
--
-- 3) Newtypes: @newtype Foo a = MkFoo ...@ creates the @Foo@ type constructor
--- of kind @* -> *@
+-- of kind @Type -> Type@
--
-- 4) Class declarations: @class Foo where@ creates the @Foo@ type constructor
--- of kind @*@
+-- of kind @Constraint@
--
-- This data type also encodes a number of primitive, built in type constructors
-- such as those for function and tuple types.
@@ -1252,16 +1252,16 @@ data FamTyConFlav
--
-- These are introduced by either a top level declaration:
--
- -- > data family T a :: *
+ -- > data family T a :: Type
--
-- Or an associated data type declaration, within a class declaration:
--
-- > class C a b where
- -- > data T b :: *
+ -- > data T b :: Type
DataFamilyTyCon
TyConRepName
- -- | An open type synonym family e.g. @type family F x y :: * -> *@
+ -- | An open type synonym family e.g. @type family F x y :: Type -> Type@
| OpenSynFamilyTyCon
-- | A closed type synonym family e.g.
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/5dce04ee039ff24c403ac451d920b1eb22488505
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/5dce04ee039ff24c403ac451d920b1eb22488505
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