diff options
Diffstat (limited to 'docs/users_guide/9.4.1-notes.rst')
| -rw-r--r-- | docs/users_guide/9.4.1-notes.rst | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/docs/users_guide/9.4.1-notes.rst b/docs/users_guide/9.4.1-notes.rst index 594d1035c2..0f92ab6eb5 100644 --- a/docs/users_guide/9.4.1-notes.rst +++ b/docs/users_guide/9.4.1-notes.rst @@ -151,6 +151,10 @@ Compiler enabled with :ghc-flag:`-Wall` (:ghc-ticket:`20531`), as a part of long-term push towards Dependent Haskell. +- In GHCi, the :ghci-cmd:`:type` command no longer instantiates quantified + type variables when given a polymorphic type. (It used to instantiate + inferred type variables.) + ``base`` library ~~~~~~~~~~~~~~~~ @@ -240,13 +244,13 @@ Compiler For example, the full type of ``newMutVar#`` is now: :: newMutVar# - :: forall s {l :: Levity} (a :: TYPE (BoxedRep l)). + :: forall {l :: Levity} s (a :: TYPE (BoxedRep l)). a -> State# s -> (# State# s, MVar# s a #) and the full type of ``writeSmallArray#`` is: :: writeSmallArray# - :: forall s {l :: Levity} (a :: TYPE (BoxedRep l)). + :: forall {l :: Levity} s (a :: TYPE (BoxedRep l)). SmallMutableArray# s a -> Int# -> a -> State# s -> State# s - ``ArrayArray#` and ``MutableArrayArray#`` have been moved from ``GHC.Prim`` to ``GHC.Exts``. @@ -258,8 +262,9 @@ Compiler representation-polymorphic. For instance: :: mkWeakNoFinalizer# - :: forall {l :: Levity} (a :: TYPE (BoxedRep l)) - {k :: Levity} (b :: TYPE (BoxedRep k)). + :: forall {l :: Levity} {k :: Levity} + (a :: TYPE (BoxedRep l)) + (b :: TYPE (BoxedRep k)). a -> b -> State# RealWorld -> (# State# RealWorld, Weak# b #) That is, the type signature now quantifies over the ``GHC.Exts.Levity`` of ``a`` @@ -272,8 +277,9 @@ Compiler than before. For example, ``catch#`` now has type: :: catch# - :: forall {r :: RuntimeRep} (a :: TYPE r) - {l :: Levity} (b :: TYPE (BoxedRep l)). + :: forall {r :: RuntimeRep} {l :: Levity} + (a :: TYPE r) + (b :: TYPE (BoxedRep l)). ( State# RealWorld -> (# State# RealWorld, a #) ) -> ( b -> State# RealWorld -> (# State# RealWorld, a #) ) -> State# RealWorld -> (# State# RealWorld, a #) @@ -289,8 +295,9 @@ Compiler Note in particular that ``raise#`` is now both representation-polymorphic (with an inferred `RuntimeRep` argument) and levity-polymorphic, with type: :: - raise# :: forall {l :: Levity} (a :: TYPE (BoxedRep l)) - {r :: RuntimeRep} (b :: TYPE r). + raise# :: forall {l :: Levity} {r :: RuntimeRep} + (a :: TYPE (BoxedRep l)) + (b :: TYPE r). a -> b - ``fork#`` and ``forkOn#`` are now representation-polymorphic. For example, ``fork#`` @@ -304,8 +311,9 @@ Compiler both levity-polymorphic and heterogeneous: :: reallyUnsafePtrEquality# - :: forall {l :: Levity} (a :: TYPE (BoxedRep l)) - {k :: Levity} (b :: TYPE (BoxedRep k)) + :: forall {l :: Levity} {k :: Levity} + (a :: TYPE (BoxedRep l)) + (b :: TYPE (BoxedRep k)) . a -> b -> Int# This means that ``GHC.Exts.reallyUnsafePtrEquality#`` can be used |