:: String_ -> _ Int

Throw an error, escaping the current computation up to the nearest catchError (if any).

runThrow (throwError e >>= k) = runThrow (throwError e)

Like throwEnvelopeErr but without providing a message.

>>> import Control.Monad.Except (runExcept)

>>> throwEnvelopeErr "BAD_ERROR" "a very bad error occurred!" :: Either (Err String) Int
Left (Err {errErr = "BAD_ERROR", errExtra = Just "a very bad error occurred!"})

A higher-order generalisation of replicate. For example

foo :: IO (String, String, String)
foo = replicateT getLine

> foo
Hello
world
!
("Hello","world","!")

Use sequenceT instead. It has a better name.

A higher-order generalisation of sequenceA. For example

> sequenceT (print 3110, putStrLn World) :: IO ((), ())
3110
World
((),())

Return the value of the variable or throw an error.