{- |

   Module      :  System.Win32.String

   Copyright   :  2013 shelarcy

   License     :  BSD-style



   Maintainer  :  shelarcy@gmail.com

   Stability   :  Provisional

   Portability :  Non-portable (Win32 API)



   Utilities for primitive marshalling of Windows' C strings.

-}

module System.Win32.String

  ( LPSTR, LPCSTR, LPWSTR, LPCWSTR

  , TCHAR, LPTSTR, LPCTSTR, LPCTSTR_

  , withTString, withTStringLen, peekTString, peekTStringLen

  , newTString

  , withTStringBuffer, withTStringBufferLen

  ) where

import System.Win32.Types



-- | Marshal a dummy Haskell string into a NUL terminated C wide string

-- using temporary storage.

--

-- * the Haskell string is created by length parameter. And the Haskell

--   string contains /only/ NUL characters.

--

-- * the memory is freed when the subcomputation terminates (either

--   normally or via an exception), so the pointer to the temporary

--   storage must /not/ be used after this.

--

withTStringBuffer :: Int -> (LPTSTR -> IO a) -> IO a

withTStringBuffer maxLength

  = let dummyBuffer = replicate maxLength '\0'

    in  withTString dummyBuffer



-- | Marshal a dummy Haskell string into a C wide string (i.e. wide

-- character array) in temporary storage, with explicit length

-- information.

--

-- * the Haskell string is created by length parameter. And the Haskell

--   string contains /only/ NUL characters.

--

-- * the memory is freed when the subcomputation terminates (either

--   normally or via an exception), so the pointer to the temporary

--   storage must /not/ be used after this.

--

withTStringBufferLen :: Int -> ((LPTSTR, Int) -> IO a) -> IO a

withTStringBufferLen maxLength

  = let dummyBuffer = replicate maxLength '\0'

    in  withTStringLen dummyBuffer