Foreign.Marshal.Error
| Copyright | (c) The FFI task force 2001 |
|---|---|
| License | BSD-style (see the file libraries/base/LICENSE) |
| Maintainer | [email protected] |
| Stability | provisional |
| Portability | portable |
| Safe Haskell | Trustworthy |
| Language | Haskell2010 |
Description
Routines for testing return values and raising a userError exception in case of values indicating an error state.
Arguments
| :: (a -> Bool) | error condition on the result of the |
| -> (a -> String) | computes an error message from erroneous results of the |
| -> IO a | the |
| -> 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.
throwIf_ :: (a -> Bool) -> (a -> String) -> IO a -> IO () Source
Like throwIf, but discarding the result
throwIfNeg :: (Ord a, Num a) => (a -> String) -> IO a -> IO a Source
Guards against negative result values
throwIfNeg_ :: (Ord a, Num a) => (a -> String) -> IO a -> IO () Source
Like throwIfNeg, but discarding the result
throwIfNull :: String -> IO (Ptr a) -> IO (Ptr a) Source
Guards against null pointers
Deprecated: use void instead
Discard the return value of an IO action
© The University of Glasgow and others
Licensed under a BSD-style license (see top of the page).
https://downloads.haskell.org/~ghc/8.10.2/docs/html/libraries/base-4.14.1.0/Foreign-Marshal-Error.html