diff options
Diffstat (limited to 'src/Utils.hs')
| -rw-r--r-- | src/Utils.hs | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/Utils.hs b/src/Utils.hs index 01ecb17..1eabd72 100644 --- a/src/Utils.hs +++ b/src/Utils.hs @@ -376,3 +376,9 @@ foldStackMessage (LException st) = case st of where fmtPos p = if useless p then "" else (" at " ++ p) useless p = "nonsense" `L.isPrefixOf` p || length p == 0 + +fold1M :: (Monad m) => (a -> a -> m a) -> [a] -> m a +fold1M _ (x:[]) = return x +fold1M f (x:y:xs) = do ret <- f x y + fold1M f (ret : xs) +fold1M _ [] = error $ "fold1M of empty list" |