Control.Monad.Loc

This package defines a MonadLoc class for monads which support Monadic Call Traces. See http:pepeiborra.posterous.com/monadic-stack-traces-that-make-a-lot-of-sense

• Traces are only provided for explicitly annotated program points.
• This package installs the MonadLoc preprocessor for this purpose. To enable it include the following pragma at the top of your haskell source files:

     { -# OPTIONS_GHC -F -pgmF MonadLoc #- }

• There is also the TH macro withLocTH exported by Control.Monad.Loc.TH

Documentation

class Monad m => MonadLoc m where

Generating stack traces for failures

Methods

withLoc :: String -> m a -> m a

withLoc records the given source location in the failure trace if the underlying monad supports recording location traces

Instances

Monad m => MonadLoc m

MonadLoc m => MonadLoc (ListT m)

(Monoid w, MonadLoc m) => MonadLoc (WriterT w m)

(Monoid w, MonadLoc m) => MonadLoc (WriterT w m)

MonadLoc m => MonadLoc (StateT s m)

MonadLoc m => MonadLoc (StateT s m)

MonadLoc m => MonadLoc (ReaderT r m)

(Error e, MonadLoc m) => MonadLoc (ErrorT e m)

(Monoid w, MonadLoc m) => MonadLoc (RWST r w s m)

(Monoid w, MonadLoc m) => MonadLoc (RWST r w s m)