Modulebase-4.20.2.0Haskell2010

Foreign.Marshal.Error

Routines for testing return values and raising a userError exception in case of values indicating an error state.

6 values

Packagebase-4.20.2.0
Exports6
LanguageHaskell2010
LicenceBSD-3-Clause
SourceError.hs

valuethrowIf

:: (a -> Bool)
error condition on the result of the IO action
-> (a -> String)
computes an error message from erroneous results of the IO action
-> IO a
the IO action to be executed
-> IO a

Execute an IO action, throwing a userError if the predicate yields True when applied to the result returned by the IO action. If no exception is raised, return the result of the computation.

valuethrowIf_ :: (a -> Bool) -> (a -> String) -> IO a -> IO ()

Like throwIf, but discarding the result

valuethrowIfNeg :: (Ord a, Num a) => (a -> String) -> IO a -> IO a

Guards against negative result values

valuethrowIfNeg_ :: (Ord a, Num a) => (a -> String) -> IO a -> IO ()

Like throwIfNeg, but discarding the result

valuethrowIfNull :: String -> IO (Ptr a) -> IO (Ptr a)

Guards against null pointers

valuevoid :: IO a -> IO ()

Deprecated. use void instead

Discard the return value of an IO action