diff options
Diffstat (limited to 'libraries/ghc-boot/GHC/Data/ShortText.hs')
| -rw-r--r-- | libraries/ghc-boot/GHC/Data/ShortText.hs | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/libraries/ghc-boot/GHC/Data/ShortText.hs b/libraries/ghc-boot/GHC/Data/ShortText.hs index 477d2b9a6d..9ea261435f 100644 --- a/libraries/ghc-boot/GHC/Data/ShortText.hs +++ b/libraries/ghc-boot/GHC/Data/ShortText.hs @@ -47,7 +47,6 @@ import Control.DeepSeq as DeepSeq import Data.Binary import qualified Data.ByteString.Char8 as B8 import qualified Data.ByteString.Short.Internal as SBS -import Data.List (uncons) import GHC.Exts import GHC.IO import GHC.Utils.Encoding @@ -101,9 +100,11 @@ splitFilePath st = DeepSeq.force $ map (ShortText . SBS.toShort) $ B8.splitWith -- question, this may or may not be the actual first character in the string due to Unicode -- non-printable characters. head :: ShortText -> Char -head st = case uncons (unpack st) of - Nothing -> error "head: Empty ShortText" - Just (hd, _) -> hd +head st + | hd:_ <- unpack st + = hd + | otherwise + = error "head: Empty ShortText" -- | /O(n)/ The 'stripPrefix' function takes two 'ShortText's and returns 'Just' the remainder of -- the second iff the first is its prefix, and otherwise Nothing. |