sdl2-gfx-0.2: src/SDL/ExceptionHelper.hs

module SDL.ExceptionHelper where

import Control.Exception       (throwIO)
import Control.Monad           (when)
import Control.Monad.IO.Class  (MonadIO, liftIO)
import Data.ByteString         (packCString)
import Data.Text               (Text)
import Data.Text.Encoding      (decodeUtf8)
import SDL                     (SDLException(SDLCallFailed))
import SDL.Raw                 (getError)

throwIfNeg_ :: (MonadIO m, Num a, Ord a) => Text -> Text -> m a -> m ()
throwIfNeg_ = throwIf_ (< 0)

throwIf_ :: MonadIO m => (a -> Bool) -> Text -> Text -> m a -> m ()
throwIf_ f caller rawf act = do
  result <- act
  liftIO $ when (f result) $ do
    err <- decodeUtf8 <$> (packCString =<< getError)
    throwIO $ SDLCallFailed caller rawf err
  return ()