base: Remove `Monad(fail)` method and reexport `MonadFail(fail)` instead

As per https://prime.haskell.org/wiki/Libraries/Proposals/MonadFail

Coauthored-by: Ben Gamari <ben@well-typed.com>

5 files changed, 0 insertions, 146 deletions

diff --git a/testsuite/tests/warnings/should_compile/T11128.hs b/testsuite/tests/warnings/should_compile/T11128.hs
deleted file mode 100644
index 23725c1e4b..0000000000
--- a/testsuite/tests/warnings/should_compile/T11128.hs
+++ /dev/null
@@ -1,50 +0,0 @@
-{-# LANGUAGE DeriveFunctor #-}
-{-# OPTIONS_GHC -fwarn-noncanonical-monad-instances  #-}
-
--- | Test noncanonical-monad-instances warnings
-module T11128 where
-
-import Control.Applicative as A
-import Control.Monad as M
-
-----------------------------------------------------------------------------
--- minimal definition
-
-data T0 a  = T0 a deriving Functor
-
-instance A.Applicative T0 where
-    pure   = T0
-    (<*>)  = M.ap
-
-instance M.Monad T0 where
-    (>>=)  = undefined
-
-----------------------------------------------------------------------------
--- trigger all 4 warnings
-
-data T1 a  = T1 a deriving Functor
-
-instance A.Applicative T1 where
-    pure   = return
-    (<*>)  = M.ap
-    (*>)   = (M.>>)
-
-instance M.Monad T1 where
-    (>>=)  = undefined
-    return = T1
-    (>>)   = undefined
-
-----------------------------------------------------------------------------
--- backward compat canonical definition
-
-data T2 a  = T2 a deriving Functor
-
-instance Applicative T2 where
-    pure   = T2
-    (<*>)  = ap
-    (*>)   = undefined
-
-instance M.Monad T2 where
-    (>>=)  = undefined
-    return = pure
-    (>>)   = (*>)
diff --git a/testsuite/tests/warnings/should_compile/T11128.stderr b/testsuite/tests/warnings/should_compile/T11128.stderr
deleted file mode 100644
index b8d788236c..0000000000
--- a/testsuite/tests/warnings/should_compile/T11128.stderr
+++ /dev/null
@@ -1,20 +0,0 @@
-
-T11128.hs:28:5: warning: [-Wnoncanonical-monad-instances]
-    Noncanonical ‘pure = return’ definition detected
-    in the instance declaration for ‘Applicative T1’.
-    Move definition from ‘return’ to ‘pure’
-
-T11128.hs:30:5: warning: [-Wnoncanonical-monad-instances]
-    Noncanonical ‘(*>) = (>>)’ definition detected
-    in the instance declaration for ‘Applicative T1’.
-    Move definition from ‘(>>)’ to ‘(*>)’
-
-T11128.hs:34:5: warning: [-Wnoncanonical-monad-instances]
-    Noncanonical ‘return’ definition detected
-    in the instance declaration for ‘Monad T1’.
-    Either remove definition for ‘return’ or define as ‘return = pure’
-
-T11128.hs:35:5: warning: [-Wnoncanonical-monad-instances]
-    Noncanonical ‘(>>)’ definition detected
-    in the instance declaration for ‘Monad T1’.
-    Either remove definition for ‘(>>)’ or define as ‘(>>) = (*>)’
diff --git a/testsuite/tests/warnings/should_compile/T11128b.hs b/testsuite/tests/warnings/should_compile/T11128b.hs
deleted file mode 100644
index 497927716c..0000000000
--- a/testsuite/tests/warnings/should_compile/T11128b.hs
+++ /dev/null
@@ -1,64 +0,0 @@
-{-# LANGUAGE DeriveFunctor #-}
-{-# OPTIONS_GHC -Wnoncanonical-monadfail-instances  #-}
-
--- | Test noncanonical-monadfail-instances warnings
-module T11128b where
-
-import Control.Applicative as A
-import Control.Monad as M
-import Control.Monad.Fail as MF
-
-----------------------------------------------------------------------------
--- minimal definition
-
-data T0 a  = T0 a deriving Functor
-
-instance A.Applicative T0 where
-    pure   = T0
-    (<*>)  = M.ap
-
-instance M.Monad T0 where
-    (>>=)  = undefined
-
-instance MF.MonadFail T0 where
-    fail   = error "fail"
-
-----------------------------------------------------------------------------
--- trigger all 2 warnings
-
-data T1 a  = T1 a deriving Functor
-
-instance A.Applicative T1 where
-    pure   = return
-    (<*>)  = M.ap
-    (*>)   = (M.>>)
-
-instance M.Monad T1 where
-    (>>=)  = undefined
-    return = T1
-    (>>)   = undefined
-    fail   = error "fail"
-
-instance MF.MonadFail T1 where
-    fail   = M.fail
-
-----------------------------------------------------------------------------
--- backward compat canonical definition
-
-data T2 a  = T2 a deriving Functor
-
-instance Applicative T2 where
-    pure   = T2
-    (<*>)  = ap
-    (*>)   = undefined
-
-instance M.Monad T2 where
-    (>>=)  = undefined
-    return = pure
-    (>>)   = (*>)
-    fail   = MF.fail
-
-instance MF.MonadFail T2 where
-    fail   = error "fail"
-
-----------------------------------------------------------------------------
diff --git a/testsuite/tests/warnings/should_compile/T11128b.stderr b/testsuite/tests/warnings/should_compile/T11128b.stderr
deleted file mode 100644
index e3fd3e83dc..0000000000
--- a/testsuite/tests/warnings/should_compile/T11128b.stderr
+++ /dev/null
@@ -1,10 +0,0 @@
-
-T11128b.hs:40:5: warning: [-Wnoncanonical-monadfail-instances]
-    Noncanonical ‘fail’ definition detected
-    in the instance declaration for ‘Monad T1’.
-    Either remove definition for ‘fail’ or define as ‘fail = Control.Monad.Fail.fail’
-
-T11128b.hs:43:5: warning: [-Wnoncanonical-monadfail-instances]
-    Noncanonical ‘fail = Control.Monad.fail’ definition detected
-    in the instance declaration for ‘MonadFail T1’.
-    Move definition from ‘Control.Monad.fail’ to ‘fail’
diff --git a/testsuite/tests/warnings/should_compile/all.T b/testsuite/tests/warnings/should_compile/all.T
index 10a3ecf12c..36e6b1beeb 100644
--- a/testsuite/tests/warnings/should_compile/all.T
+++ b/testsuite/tests/warnings/should_compile/all.T
@@ -9,8 +9,6 @@ test('T10908', normal, compile, [''])
 test('T10930', normal, compile, [''])
 test('T10930b', normal, compile, [''])
 test('T11077', normal, compile, ['-fwarn-missing-exported-signatures'])
-test('T11128', normal, compile, [''])
-test('T11128b', normal, compile, [''])
 test('T13256', normal, compile, [''])
 test('T15460', normal, compile, [''])
 test('PluralS', normal, compile, [''])