Control.Monad.Trans.Trace

Documentation

data TraceT t e m α

A concrete monad transformer TraceT t e m where t is the type of tags/breadcrumbs, e is the type of errors, and m is the underlying monad.

Instances

MonadBase b m => MonadBase b (TraceT t e m)

MonadBaseControl b m => MonadBaseControl b (TraceT t e m)

Monad m => MonadError e (TraceT t e m)

Monad m => MonadTrace t (TraceT t e m)

MonadTrans (TraceT t e)

MonadTransControl (TraceT t e)

(Monad m, Monoid e) => Alternative (TraceT t e m)

Monad m => Monad (TraceT t e m)

Monad m => Functor (TraceT t e m)

Monad m => Applicative (TraceT t e m)

MonadIO m => MonadIO (TraceT t e m)

data StT (TraceT t e) = StTraceT {

• unStTraceT :: StT (StateT (Seq t)) (StT (EitherT e) α)

}

data StM (TraceT t e m) = StMTraceT {

• unStMTraceT :: ComposeSt (TraceT t e) m α

}

runTraceT :: (Functor m, Monad m) => TraceT t e m α -> EitherT (ErrorTrace t e) m α

Run a traced traced computation to get either its result, or an error and its provenience (ErrorTrace).

readTrace :: MonadTrace t m => m (Seq t)

Realize your own trace