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| author | Herbert Valerio Riedel <hvr@gnu.org> | 2017-09-09 16:29:23 +0200 |
|---|---|---|
| committer | Herbert Valerio Riedel <hvr@gnu.org> | 2017-09-09 16:43:36 +0200 |
| commit | 346e562adffd44edd8c31328c0280543d7dd75c1 (patch) | |
| tree | e10042e1640a8ad944c86d8590c45bb02254d2f6 /compiler/parser | |
| parent | dab0e515eadecaee3e9e9f5f8eee3159fa39bb27 (diff) | |
| download | haskell-346e562adffd44edd8c31328c0280543d7dd75c1.tar.gz | |
Canonicalise MonoidFail instances in GHC
IOW, code compiles -Wnoncanonical-monoidfail-instances clean now
This is easy now since we require GHC 8.0/base-4.9 or later
for bootstrapping.
Note that we can easily enable `MonadFail` via
default-extensions: MonadFailDesugaring
in compiler/ghc.cabal.in
which currently would point out that NatM doesn't have
a proper `fail` method, even though failable patterns
are made use of:
compiler/nativeGen/SPARC/CodeGen.hs:425:25: error:
* No instance for (Control.Monad.Fail.MonadFail NatM)
arising from a do statement
with the failable pattern ‘(dyn_c, [dyn_r])’
Diffstat (limited to 'compiler/parser')
| -rw-r--r-- | compiler/parser/Lexer.x | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/compiler/parser/Lexer.x b/compiler/parser/Lexer.x index c5332fbe2f..5d3d65d035 100644 --- a/compiler/parser/Lexer.x +++ b/compiler/parser/Lexer.x @@ -77,7 +77,7 @@ module Lexer ( -- base import Control.Monad -import Control.Monad.Fail +import Control.Monad.Fail as MonadFail import Data.Bits import Data.Char import Data.List @@ -1890,7 +1890,7 @@ instance Applicative P where instance Monad P where (>>=) = thenP - fail = failP + fail = MonadFail.fail instance MonadFail P where fail = failP |