module System.TimeIt(timeIt, timeItShow, timeItNamed, timeItT) where
import System.CPUTime
import Text.Printf
import Control.Monad.IO.Class (MonadIO(liftIO))

-- | Wrap a 'MonadIO' computation so that it prints out the execution time.
timeIt :: MonadIO m => m a -> m a
timeIt :: forall (m :: * -> *) a. MonadIO m => m a -> m a
timeIt = String -> m a -> m a
forall (m :: * -> *) a. MonadIO m => String -> m a -> m a
timeItNamed String
"CPU time"

-- | Like 'timeIt', but uses the 'show' rendering of @a@ as label for the
-- timing.
--
-- @since 2.0
timeItShow :: (MonadIO m, Show a) => m a -> m a
timeItShow :: forall (m :: * -> *) a. (MonadIO m, Show a) => m a -> m a
timeItShow m a
ioa = do
    (Double
t, a
a) <- m a -> m (Double, a)
forall (m :: * -> *) a. MonadIO m => m a -> m (Double, a)
timeItT m a
ioa
    IO () -> m ()
forall a. IO a -> m a
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> IO () -> m ()
forall a b. (a -> b) -> a -> b
$ String -> Double -> IO ()
forall r. PrintfType r => String -> r
printf (a -> String
forall a. Show a => a -> String
show a
a String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
": %6.2fs\n") Double
t
    a -> m a
forall a. a -> m a
forall (m :: * -> *) a. Monad m => a -> m a
return a
a

-- | Like 'timeIt', but uses the 'String' as label for the timing.
--
-- @since 2.0
timeItNamed :: MonadIO m => String -> m a -> m a
timeItNamed :: forall (m :: * -> *) a. MonadIO m => String -> m a -> m a
timeItNamed String
name m a
ioa = do
    (Double
t, a
a) <- m a -> m (Double, a)
forall (m :: * -> *) a. MonadIO m => m a -> m (Double, a)
timeItT m a
ioa
    IO () -> m ()
forall a. IO a -> m a
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> IO () -> m ()
forall a b. (a -> b) -> a -> b
$ String -> Double -> IO ()
forall r. PrintfType r => String -> r
printf (String
name String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
": %6.2fs\n") Double
t
    a -> m a
forall a. a -> m a
forall (m :: * -> *) a. Monad m => a -> m a
return a
a

-- | Wrap a 'MonadIO' computation so that it returns execution time in seconds,
-- as well as the result value.
timeItT :: MonadIO m => m a -> m (Double, a)
timeItT :: forall (m :: * -> *) a. MonadIO m => m a -> m (Double, a)
timeItT m a
ioa = do
    Integer
t1 <- IO Integer -> m Integer
forall a. IO a -> m a
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO IO Integer
getCPUTime
    a
a <- m a
ioa
    Integer
t2 <- IO Integer -> m Integer
forall a. IO a -> m a
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO IO Integer
getCPUTime
    let t :: Double
        t :: Double
t = Integer -> Double
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Integer
t2Integer -> Integer -> Integer
forall a. Num a => a -> a -> a
-Integer
t1) Double -> Double -> Double
forall a. Num a => a -> a -> a
* Double
1e-12
    (Double, a) -> m (Double, a)
forall a. a -> m a
forall (m :: * -> *) a. Monad m => a -> m a
return (Double
t, a
a)