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Diffstat (limited to 'src/CabalHelper/Compiletime/Log.hs')
-rw-r--r-- | src/CabalHelper/Compiletime/Log.hs | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/src/CabalHelper/Compiletime/Log.hs b/src/CabalHelper/Compiletime/Log.hs new file mode 100644 index 0000000..eefb30e --- /dev/null +++ b/src/CabalHelper/Compiletime/Log.hs @@ -0,0 +1,40 @@ +-- cabal-helper: Simple interface to Cabal's configuration state +-- Copyright (C) 2018 Daniel Gröber <cabal-helper@dxld.at> +-- +-- This program is free software: you can redistribute it and/or modify +-- it under the terms of the GNU General Public License as published by +-- the Free Software Foundation, either version 3 of the License, or +-- (at your option) any later version. +-- +-- This program is distributed in the hope that it will be useful, +-- but WITHOUT ANY WARRANTY; without even the implied warranty of +-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +-- GNU General Public License for more details. +-- +-- You should have received a copy of the GNU General Public License +-- along with this program. If not, see <http://www.gnu.org/licenses/>. + +{-| +Module : CabalHelper.Compiletime.Log +Description : Logging utilities +License : GPL-3 +-} + +module CabalHelper.Compiletime.Log where + +import Control.Monad.IO.Class +import System.IO +import System.IO.Error + +import CabalHelper.Compiletime.Types + +logIOError :: Verbose => String -> IO (Maybe a) -> IO (Maybe a) +logIOError label a = do + a `catchIOError` \ex -> do + vLog $ label ++ ": " ++ show ex + return Nothing + +vLog :: (MonadIO m, Verbose) => String -> m () +vLog msg + | ?verbose = liftIO $ hPutStrLn stderr msg + | otherwise = return () |