diff options
Diffstat (limited to 'compiler/utils')
| -rw-r--r-- | compiler/utils/Util.hs | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/compiler/utils/Util.hs b/compiler/utils/Util.hs index c484ba90ea..e8d20e3208 100644 --- a/compiler/utils/Util.hs +++ b/compiler/utils/Util.hs @@ -49,6 +49,8 @@ module Util ( changeLast, + whenNonEmpty, + -- * Tuples fstOf3, sndOf3, thdOf3, firstM, first3M, secondM, @@ -137,6 +139,7 @@ import Data.Data import Data.IORef ( IORef, newIORef, atomicModifyIORef' ) import System.IO.Unsafe ( unsafePerformIO ) import Data.List hiding (group) +import Data.List.NonEmpty ( NonEmpty(..) ) import GHC.Exts import GHC.Stack (HasCallStack) @@ -610,6 +613,10 @@ changeLast [] _ = panic "changeLast" changeLast [_] x = [x] changeLast (x:xs) x' = x : changeLast xs x' +whenNonEmpty :: Applicative m => [a] -> (NonEmpty a -> m ()) -> m () +whenNonEmpty [] _ = pure () +whenNonEmpty (x:xs) f = f (x :| xs) + {- ************************************************************************ * * |