Control.Lens.Internal.Exception

Methods

• handler :: Typeable a => Getting (First a) e a -> (a -> m r) -> h r

  This builds a Handler for just the targets of a given Prism (or any Getter, really).

  catches ... [ handler _AssertionFailed (s -> print $ "Assertion Failed\n" ++ s)
              , handler _ErrorCall (s -> print $ "Error\n" ++ s)
              ]
  

  This works ith both the Handler type provided by Control.Exception:

  handler :: Getter     SomeException a -> (a -> IO r) -> Handler r
  handler :: Fold       SomeException a -> (a -> IO r) -> Handler r
  handler :: Control.Lens.Prism.Prism'     SomeException a -> (a -> IO r) -> Handler r
  handler :: Control.Lens.Lens.Lens'      SomeException a -> (a -> IO r) -> Handler r
  handler :: Control.Lens.Traversal.Traversal' SomeException a -> (a -> IO r) -> Handler r
  

  and with the Handler type provided by Control.Monad.Catch:

  handler :: Getter     SomeException a -> (a -> m r) -> Handler m r
  handler :: Fold       SomeException a -> (a -> m r) -> Handler m r
  handler :: Control.Lens.Prism.Prism'     SomeException a -> (a -> m r) -> Handler m r
  handler :: Control.Lens.Lens.Lens'      SomeException a -> (a -> m r) -> Handler m r
  handler :: Control.Lens.Traversal.Traversal' SomeException a -> (a -> m r) -> Handler m r
  

  and with the Handler type provided by Control.Monad.Error.Lens:

  handler :: Getter     e a -> (a -> m r) -> Handler e m r
  handler :: Fold       e a -> (a -> m r) -> Handler e m r
  handler :: Control.Lens.Prism.Prism'     e a -> (a -> m r) -> Handler e m r
  handler :: Control.Lens.Lens.Lens'      e a -> (a -> m r) -> Handler e m r
  handler :: Control.Lens.Traversal.Traversal' e a -> (a -> m r) -> Handler e m r
  

• handler_ :: Typeable a => Getting (First a) e a -> m r -> h r

  This builds a Handler for just the targets of a given Control.Lens.Prism.Prism (or any Getter, really). that ignores its input and just recovers with the stated monadic action.

  catches ... [ handler_ _NonTermination (return "looped")
              , handler_ _StackOverflow (return "overflow")
              ]
  

  This works with the Handler type provided by Control.Exception:

  handler_ :: Getter     SomeException a -> IO r -> Handler r
  handler_ :: Fold       SomeException a -> IO r -> Handler r
  handler_ :: Control.Lens.Prism.Prism'     SomeException a -> IO r -> Handler r
  handler_ :: Control.Lens.Lens.Lens'      SomeException a -> IO r -> Handler r
  handler_ :: Control.Lens.Traversal.Traversal' SomeException a -> IO r -> Handler r
  

  and with the Handler type provided by Control.Monad.Catch:

  handler_ :: Getter     SomeException a -> m r -> Handler m r
  handler_ :: Fold       SomeException a -> m r -> Handler m r
  handler_ :: Control.Lens.Prism.Prism'     SomeException a -> m r -> Handler m r
  handler_ :: Control.Lens.Lens.Lens'      SomeException a -> m r -> Handler m r
  handler_ :: Control.Lens.Traversal.Traversal' SomeException a -> m r -> Handler m r
  

  and with the Handler type provided by Control.Monad.Error.Lens:

  handler_ :: Getter     e a -> m r -> Handler e m r
  handler_ :: Fold       e a -> m r -> Handler e m r
  handler_ :: Control.Lens.Prism.Prism'     e a -> m r -> Handler e m r
  handler_ :: Control.Lens.Lens.Lens'      e a -> m r -> Handler e m r
  handler_ :: Control.Lens.Traversal.Traversal' e a -> m r -> Handler e m r