Treat kind/type variables identically in 'forall'wip/no-kind-vars

1 files changed, 0 insertions, 53 deletions

diff --git a/docs/users_guide/using-warnings.rst b/docs/users_guide/using-warnings.rst
index 03ca184531..27efd9f899 100644
--- a/docs/users_guide/using-warnings.rst
+++ b/docs/users_guide/using-warnings.rst
@@ -123,7 +123,6 @@ The following flags are simple ways to select standard "packages" of warnings:
         * :ghc-flag:`-Wmissing-monadfail-instances`
         * :ghc-flag:`-Wsemigroup`
         * :ghc-flag:`-Wnoncanonical-monoid-instances`
-        * :ghc-flag:`-Wimplicit-kind-vars`
         * :ghc-flag:`-Wstar-is-type`
 
 .. ghc-flag:: -Wno-compat
@@ -776,58 +775,6 @@ of ``-W(no-)*``.
 
     This warning is off by default.
 
-.. ghc-flag:: -Wimplicit-kind-vars
-    :shortdesc: warn when kind variables are brought into scope implicitly despite
-        the "forall-or-nothing" rule
-    :type: dynamic
-    :reverse: -Wno-implicit-kind-vars
-    :category:
-
-    :since: 8.6
-
-    `GHC proposal #24
-    <https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0024-no-kind-vars.rst>`__
-    prescribes to treat kind variables and type variables identically in
-    ``forall``, removing the legacy distinction between them.
-
-    Consider the following examples: ::
-
-        f :: Proxy a -> Proxy b -> ()
-        g :: forall a b. Proxy a -> Proxy b -> ()
-
-    ``f`` does not use an explicit ``forall``, so type variables ``a`` and ``b``
-    are brought into scope implicitly. ``g`` quantifies both ``a`` and ``b``
-    explicitly. Both ``f`` and ``g`` work today and will continue to work in the
-    future because they adhere to the "forall-or-nothing" rule: either all type
-    variables in a function definition are introduced explicitly or implicitly,
-    there is no middle ground.
-
-    A violation of the "forall-or-nothing" rule looks like this: ::
-
-        m :: forall a. Proxy a -> Proxy b -> ()
-
-    ``m`` does not introduce one of the variables, ``b``, and thus is rejected.
-
-    However, consider the following example: ::
-
-        n :: forall a. Proxy (a :: k) -> ()
-
-    While ``n`` uses ``k`` without introducing it and thus violates the rule, it
-    is currently accepted. This is because ``k`` in ``n`` is considered a kind
-    variable, as it occurs in a kind signature. In reality, the line between
-    type variables and kind variables is blurry, as the following example
-    demonstrates: ::
-
-        kindOf :: forall a. Proxy (a :: k) -> Proxy k
-
-    In ``kindOf``, the ``k`` variable is used both in a kind position and a type
-    position. Currently, ``kindOf`` happens to be accepted as well.
-
-    In a future release of GHC, both ``n`` and ``kindOf`` will be rejected per
-    the "forall-or-nothing" rule. This warning, being part of the
-    :ghc-flag:`-Wcompat` option group, allows to detect this before the actual
-    breaking change takes place.
-
 .. ghc-flag:: -Wincomplete-patterns
     :shortdesc: warn when a pattern match could fail
     :type: dynamic