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Diffstat (limited to 'docs/users_guide/exts/primitives.rst')
| -rw-r--r-- | docs/users_guide/exts/primitives.rst | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/docs/users_guide/exts/primitives.rst b/docs/users_guide/exts/primitives.rst index 2b8e88aa23..46c8dfb13b 100644 --- a/docs/users_guide/exts/primitives.rst +++ b/docs/users_guide/exts/primitives.rst @@ -83,11 +83,11 @@ The Haskell Report describes that ``*`` (spelled ``Type`` and imported from such as ``Int``. Furthermore, type constructors can have kinds with arrows; for example, ``Maybe`` has kind ``Type -> Type``. Unboxed types have a kind that specifies their runtime representation. For example, the type ``Int#`` has kind -``TYPE 'IntRep`` and ``Double#`` has kind ``TYPE 'DoubleRep``. These kinds say +``TYPE IntRep`` and ``Double#`` has kind ``TYPE DoubleRep``. These kinds say that the runtime representation of an ``Int#`` is a machine integer, and the runtime representation of a ``Double#`` is a machine double-precision floating point. In contrast, the kind ``Type`` is actually just a synonym for ``TYPE -'LiftedRep``. More details of the ``TYPE`` mechanisms appear in the `section +LiftedRep``. More details of the ``TYPE`` mechanisms appear in the `section on runtime representation polymorphism <#runtime-rep>`__. Given that ``Int#``'s kind is not ``Type``, then it follows that ``Maybe @@ -326,13 +326,13 @@ of a ``newtype``. For example, the type :: newtype A = MkA Int# is accepted when this extension is enabled. This creates a type -``A :: TYPE 'IntRep`` and a data constructor ``MkA :: Int# -> A``. +``A :: TYPE IntRep`` and a data constructor ``MkA :: Int# -> A``. Although the kind of ``A`` is inferred by GHC, there is nothing visually distinctive about this type that indicated that is it not of kind ``Type`` like newtypes typically are. `GADTSyntax <#gadt-style>`__ can be used to provide a kind signature for additional clarity :: - newtype A :: TYPE 'IntRep where + newtype A :: TYPE IntRep where MkA :: Int# -> A The ``Coercible`` machinery works with unlifted newtypes just like it does with @@ -362,14 +362,14 @@ instances. In particular, :extension:`UnliftedNewtypes` permits a permitted: :: class Foo a where - data FooKey a :: TYPE 'IntRep + data FooKey a :: TYPE IntRep class Bar (r :: RuntimeRep) where data BarType r :: TYPE r instance Foo Bool where newtype FooKey Bool = FooKeyBoolC Int# - instance Bar 'WordRep where - newtype BarType 'WordRep = BarTypeWordRepC Word# + instance Bar WordRep where + newtype BarType WordRep = BarTypeWordRepC Word# It is worth noting that :extension:`UnliftedNewtypes` is *not* required to give the data families themselves return kinds involving ``TYPE``, such as the |