-- Copyright 2020 United States Government as represented by the Administrator -- of the National Aeronautics and Space Administration. All Rights Reserved. -- -- Disclaimers -- -- No Warranty: THE SUBJECT SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY -- OF ANY KIND, EITHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT -- LIMITED TO, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL CONFORM TO -- SPECIFICATIONS, ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A -- PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, ANY WARRANTY THAT THE -- SUBJECT SOFTWARE WILL BE ERROR FREE, OR ANY WARRANTY THAT DOCUMENTATION, IF -- PROVIDED, WILL CONFORM TO THE SUBJECT SOFTWARE. THIS AGREEMENT DOES NOT, IN -- ANY MANNER, CONSTITUTE AN ENDORSEMENT BY GOVERNMENT AGENCY OR ANY PRIOR -- RECIPIENT OF ANY RESULTS, RESULTING DESIGNS, HARDWARE, SOFTWARE PRODUCTS OR -- ANY OTHER APPLICATIONS RESULTING FROM USE OF THE SUBJECT SOFTWARE. FURTHER, -- GOVERNMENT AGENCY DISCLAIMS ALL WARRANTIES AND LIABILITIES REGARDING -- THIRD-PARTY SOFTWARE, IF PRESENT IN THE ORIGINAL SOFTWARE, AND DISTRIBUTES -- IT "AS IS." -- -- Waiver and Indemnity: RECIPIENT AGREES TO WAIVE ANY AND ALL CLAIMS AGAINST -- THE UNITED STATES GOVERNMENT, ITS CONTRACTORS AND SUBCONTRACTORS, AS WELL AS -- ANY PRIOR RECIPIENT. IF RECIPIENT'S USE OF THE SUBJECT SOFTWARE RESULTS IN -- ANY LIABILITIES, DEMANDS, DAMAGES, EXPENSES OR LOSSES ARISING FROM SUCH USE, -- INCLUDING ANY DAMAGES FROM PRODUCTS BASED ON, OR RESULTING FROM, RECIPIENT'S -- USE OF THE SUBJECT SOFTWARE, RECIPIENT SHALL INDEMNIFY AND HOLD HARMLESS THE -- UNITED STATES GOVERNMENT, ITS CONTRACTORS AND SUBCONTRACTORS, AS WELL AS ANY -- PRIOR RECIPIENT, TO THE EXTENT PERMITTED BY LAW. RECIPIENT'S SOLE REMEDY -- FOR ANY SUCH MATTER SHALL BE THE IMMEDIATE, UNILATERAL TERMINATION OF THIS -- AGREEMENT. -- -- | Auxiliary functions for working with values of type 'ByteString'. module Data.ByteString.Extra where import Control.Exception ( catch ) import qualified Data.ByteString.Lazy as B import System.IO.Error ( isDoesNotExistError ) -- * Safe I/O -- | Safely read a file into a lazy 'ByteString', returning a 'Left' error -- message if the file cannot be opened. safeReadFile :: FilePath -> IO (Either String B.ByteString) safeReadFile :: String -> IO (Either String ByteString) safeReadFile String fp = forall e a. Exception e => IO a -> (e -> IO a) -> IO a catch (forall (m :: * -> *) a. Monad m => a -> m a return forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b <$> String -> IO ByteString B.readFile String fp) forall a b. (a -> b) -> a -> b $ \IOError e -> if IOError -> Bool isDoesNotExistError IOError e then forall (m :: * -> *) a. Monad m => a -> m a return forall a b. (a -> b) -> a -> b $ forall a b. a -> Either a b Left forall a b. (a -> b) -> a -> b $ String -> String strByteStringFileNotFound String fp else forall (m :: * -> *) a. Monad m => a -> m a return forall a b. (a -> b) -> a -> b $ forall a b. a -> Either a b Left forall a b. (a -> b) -> a -> b $ String -> String strByteStringCannotOpenFile String fp -- ** Error messages -- | File-not-found message. strByteStringFileNotFound :: FilePath -> String strByteStringFileNotFound :: String -> String strByteStringFileNotFound String fp = String "File not found: " forall a. [a] -> [a] -> [a] ++ String fp -- | Cannot-open-file message. strByteStringCannotOpenFile :: FilePath -> String strByteStringCannotOpenFile :: String -> String strByteStringCannotOpenFile String fp = String "Error opening file " forall a. [a] -> [a] -> [a] ++ String fp