Control.Eff.Log

Documentation

data Log l v

Simple log effect, useful in pure code

Instances

(MonadBase m m, Lifted m r, MonadBaseControl m (Eff r)) => MonadBaseControl m (Eff ((:) (* -> *) (Log l) r))

Associated Types

type StM (Eff (((* -> *) ': Log l) r) :: * -> *) a :: *

Methods

liftBaseWith :: (RunInBase (Eff (((* -> *) ': Log l) r)) m -> m a) -> Eff (((* -> *) ': Log l) r) a

restoreM :: StM (Eff (((* -> *) ': Log l) r)) a -> Eff (((* -> *) ': Log l) r) a

type StM (Eff ((:) (* -> *) (Log l) r)) a

type StM (Eff ((:) (* -> *) (Log l) r)) a = StM (Eff r) (a, [l])

data LogM m l v

A more advanced version of Log. Adds an ability to log from multiple threads.

Instances

(MonadBase m m, Lifted m r, MonadBaseControl m (Eff r)) => MonadBaseControl m (Eff ((:) (* -> *) (LogM m l) r))

Associated Types

type StM (Eff (((* -> *) ': LogM m l) r) :: * -> *) a :: *

Methods

liftBaseWith :: (RunInBase (Eff (((* -> *) ': LogM m l) r)) m -> m a) -> Eff (((* -> *) ': LogM m l) r) a

restoreM :: StM (Eff (((* -> *) ': LogM m l) r)) a -> Eff (((* -> *) ': LogM m l) r) a

type StM (Eff ((:) (* -> *) (LogM m l) r)) a

type StM (Eff ((:) (* -> *) (LogM m l) r)) a = StM (Eff r) a

type Logger m l = l -> m ()

Monadic action that does the real logging

stdoutLogger :: (LogMessage l, MonadBase IO m) => Logger m l

Logger that outputs messages to stdout

stderrLogger :: (LogMessage l, MonadBase IO m) => Logger m l

Logger that outputs messages to stderr

class LogMessage l where

Handy typeclass to convert log messages for output

Minimal complete definition

toMsg

Methods

toMsg :: l -> ByteString

Instances

LogMessage ByteString

Methods

toMsg :: ByteString -> ByteString

LogMessage Text

Methods

toMsg :: Text -> ByteString

LogMessage [Char]

Methods

toMsg :: [Char] -> ByteString

logE :: Member (Log l) r => l -> Eff r ()

Log something.

logM :: (Member (LogM m l) r, Lifted m r) => l -> Eff r ()

Log something using LogM effect

filterLog :: forall l r a. Member (Log l) r => (l -> Bool) -> Eff r a -> Eff r a

Filter Log entries with a predicate.

Note that, most of the time an explicit type signature for the predicate will be required.

filterLog' :: Member (Log l) r => (l -> Bool) -> proxy l -> Eff r a -> Eff r a

Filter Log entries with a predicate and a proxy.

This is the same as filterLog but with a proxy l for type inference.

runLogPure :: Eff (Log l ': r) a -> Eff r (a, [l])

Collect log messages in a list.

runLog :: Lifted m r => Logger m l -> Eff (Log l ': r) a -> Eff r a

Run the Logger action in the base monad for every log line.

runLogM :: Lifted m r => Logger m l -> Eff (LogM m l ': r) a -> Eff r a

Run the Logger action in the base monad for every log line.