| Portability | Windows |
|---|---|
| Stability | experimental |
| Maintainer | mikesteele81@gmail.com |
| Safe Haskell | Trustworthy |
System.Win32.Error
Description
This package assumes that you will be using strict Text values for string
handling. Consider using the following language pragma and import
statements:
{-# LANGUAGE OverloadedStrings #-}
module Main where
import Data.Text (Text)
import qualified Data.Text as T
import qualified Data.Text.Foreign as T
This module is intended to be imported qualified.
import System.Win32.Errors (ErrCode, Win32Exception) import qualified System.Win32.Errors as E
See the Win32Exception type's documentation for an instructions on
working with functions that may throw exceptions of this type.
- data Win32Exception = Win32Exception {}
- tryWin32 :: IO a -> IO (Either Win32Exception a)
- toDWORD :: ErrCode -> DWORD
- fromDWORD :: DWORD -> ErrCode
- data ErrCode
- = InvalidHandleValue
- | Success
- | FileNotFound
- | PathNotFound
- | AccessDenied
- | InvalidHandle
- | InvalidData
- | InvalidDrive
- | CurrentDirectory
- | NoMoreFiles
- | CallNotImplemented
- | MoreData
- | NoMoreItems
- | ServiceAlreadyRunning
- | ServiceDisabled
- | ServiceDoesNotExist
- | ServiceCannotAcceptCtrl
- | ServiceNotActive
- | FailedServiceControllerConnect
- | ExceptionInService
- | ServiceSpecificError
- | ServiceNotInExe
- | NotAReparsePoint
- | DhcpSubnetNotPresent
- | DhcpElementCantRemove
- | DhcpOptionNotPresent
- | DhcpJetError
- | DhcpNotReservedClient
- | DhcpInvalidRange
- | Other !DWORD
Documentation
data Win32Exception Source
Exception type for Win32 errors.
This type will be thrown as an extensible exception when a foreign call out
to part of the Win32 indicates that an error has occurred. In most cases you
should wrap an IO computation in a call to tryWin32.
The following example uses the custom createFile function described in
System.Win32.Error.Foreign:
eHandle <- do
h <- E.tryWin32 $ createFile "c:\\missing.txt" gENERIC_READ oPEN_EXISTING
-- perform other actions
return h
case eHandle of
Right handle -> do
-- do something with the file handle
Left w32Err -> do
case E.errCode w32Err of
E.InvalidHandle -> do
-- perform cleanup
-- handle other error codes.
T.putStrLn $ E.systemMessage w32Err
Constructors
| Win32Exception | |
tryWin32 :: IO a -> IO (Either Win32Exception a)Source
Actions calling out to Win32 may throw exceptions. Wrapping the action in
tryWin32 will catch Win32Exception exceptions, but will allow any other
exception type to pass through.
Win32 actions typically return an error code to indicate success or failure. These codes are intended to be globally unique, though there may be some overlap. MSDN documents which errors may be returned by any given action.
The naming of errors follows a convention. An error such as ERROR_SUCCESS
becomes Success, ERROR_FILE_NOT_FOUND becomes FileNotFound, and so
on. There are thousands of errors, so it would be impractical to add them
all. The Other constructor is used to represent error codes which are not
handled specifically.
User's of this library are encouraged to submit new error codes. Add new entries to System.Win32.Errors.Mapping. Send your pull requests along with a link to relevent documentation to https://github.com/mikesteele81/Win32-errors.git.
Constructors