diff options
Diffstat (limited to 'docs/users_guide')
| -rw-r--r-- | docs/users_guide/9.4.1-notes.rst | 22 | ||||
| -rw-r--r-- | docs/users_guide/release-notes.rst | 1 |
2 files changed, 23 insertions, 0 deletions
diff --git a/docs/users_guide/9.4.1-notes.rst b/docs/users_guide/9.4.1-notes.rst new file mode 100644 index 0000000000..188593872e --- /dev/null +++ b/docs/users_guide/9.4.1-notes.rst @@ -0,0 +1,22 @@ +.. _release-9-4-1: + +Version 9.4.1 +============== + +``base`` library +~~~~~~~~~~~~~~~~ + +- ``GHC.Exts.magicDict`` now has the type: :: + + magicDict :: forall {rr :: RuntimeRep} dt st (r :: TYPE rr). (dt => r) -> st -> r + + ``magicDict`` can now be used without defining an intermediate data type. For + example, the ``withTypeable`` function from the ``Data.Typeable`` module can + now be defined as: :: + + withTypeable :: forall k (a :: k) rep (r :: TYPE rep). () + => TypeRep a -> (Typeable a => r) -> r + withTypeable rep k = magicDict @(Typeable a) k rep + + Note that the explicit type application is required, as the call to + ``magicDict`` would be ambiguous otherwise. diff --git a/docs/users_guide/release-notes.rst b/docs/users_guide/release-notes.rst index 92d4277a67..8b1313d8fe 100644 --- a/docs/users_guide/release-notes.rst +++ b/docs/users_guide/release-notes.rst @@ -6,3 +6,4 @@ Release notes 9.0.1-notes 9.2.1-notes + 9.4.1-notes |