[project @ 2003-08-22 23:44:40 by sof]

[haskell-directory.git] / System / Directory.hs

diff --git a/System/Directory.hs b/System/Directory.hs
index abccc68..0383b82 100644 (file)
--- a/System/Directory.hs
+++ b/System/Directory.hs
@@ -14,22 +14,10 @@
 
 module System.Directory 
    ( 
-     -- $intro
-
-     -- * Permissions
-
-     -- $permissions
-
-     Permissions(
-       Permissions,
-       readable,               -- :: Permissions -> Bool 
-       writable,               -- :: Permissions -> Bool
-       executable,             -- :: Permissions -> Bool
-       searchable              -- :: Permissions -> Bool
-     )
+    -- $intro
 
     -- * Actions on directories
-    , createDirectory          -- :: FilePath -> IO ()
+      createDirectory          -- :: FilePath -> IO ()
     , removeDirectory          -- :: FilePath -> IO ()
     , renameDirectory          -- :: FilePath -> FilePath -> IO ()
 
@@ -45,7 +33,17 @@ module System.Directory
     , doesFileExist            -- :: FilePath -> IO Bool
     , doesDirectoryExist        -- :: FilePath -> IO Bool
 
-    -- * Setting and retrieving permissions
+    -- * Permissions
+
+    -- $permissions
+
+    , Permissions(
+       Permissions,
+       readable,               -- :: Permissions -> Bool
+       writable,               -- :: Permissions -> Bool
+       executable,             -- :: Permissions -> Bool
+       searchable              -- :: Permissions -> Bool
+      )
 
     , getPermissions            -- :: FilePath -> IO Permissions
     , setPermissions           -- :: FilePath -> Permissions -> IO ()
@@ -120,13 +118,25 @@ data Permissions
     executable, searchable :: Bool 
    } deriving (Eq, Ord, Read, Show)
 
+{- |The 'getPermissions' operation returns the
+permissions for the file or directory.
+
+The operation may fail with:
+
+* 'isPermissionError' if the user is not permitted to access
+  the permissions; or
+
+* 'isDoesNotExistError' if the file or directory does not exist.
+
+-}
+
 getPermissions :: FilePath -> IO Permissions
 getPermissions name = do
   withCString name $ \s -> do
   read  <- c_access s r_OK
   write <- c_access s w_OK
   exec  <- c_access s x_OK
-  withFileStatus name $ \st -> do
+  withFileStatus "getPermissions" name $ \st -> do
   is_dir <- isDirectory st
   return (
     Permissions {
@@ -137,6 +147,18 @@ getPermissions name = do
     }
    )
 
+{- |The 'setPermissions' operation sets the
+permissions for the file or directory.
+
+The operation may fail with:
+
+* 'isPermissionError' if the user is not permitted to set
+  the permissions; or
+
+* 'isDoesNotExistError' if the file or directory does not exist.
+
+-}
+
 setPermissions :: FilePath -> Permissions -> IO ()
 setPermissions name (Permissions r w e s) = do
     let
@@ -333,7 +355,7 @@ Either path refers to an existing non-directory object.
 
 renameDirectory :: FilePath -> FilePath -> IO ()
 renameDirectory opath npath =
-   withFileStatus opath $ \st -> do
+   withFileStatus "renameDirectory" opath $ \st -> do
    is_dir <- isDirectory st
    if (not is_dir)
        then ioException (IOError Nothing InappropriateType "renameDirectory"
@@ -390,7 +412,7 @@ Either path refers to an existing directory.
 
 renameFile :: FilePath -> FilePath -> IO ()
 renameFile opath npath =
-   withFileOrSymlinkStatus opath $ \st -> do
+   withFileOrSymlinkStatus "renameFile" opath $ \st -> do
    is_dir <- isDirectory st
    if is_dir
        then ioException (IOError Nothing InappropriateType "renameFile"
@@ -549,43 +571,57 @@ setCurrentDirectory path = do
        throwErrnoIfMinus1Retry_ "setCurrentDirectory" (c_chdir s)
        -- ToDo: add path to error
 
-{- |To clarify, 'doesDirectoryExist' returns 'True' if a file system object
-exist, and it's a directory. 'doesFileExist' returns 'True' if the file
-system object exist, but it's not a directory (i.e., for every other 
-file system object that is not a directory.) 
+{- |The operation 'doesDirectoryExist' returns 'True' if the argument file
+exists and is a directory, and 'False' otherwise.
 -}
 
 doesDirectoryExist :: FilePath -> IO Bool
 doesDirectoryExist name = 
  catch
-   (withFileStatus name $ \st -> isDirectory st)
+   (withFileStatus "doesDirectoryExist" name $ \st -> isDirectory st)
    (\ _ -> return False)
 
+{- |The operation 'doesFileExist' returns 'True'
+if the argument file exists and is not a directory, and 'False' otherwise.
+-}
+
 doesFileExist :: FilePath -> IO Bool
 doesFileExist name = do 
  catch
-   (withFileStatus name $ \st -> do b <- isDirectory st; return (not b))
+   (withFileStatus "doesFileExist" name $ \st -> do b <- isDirectory st; return (not b))
    (\ _ -> return False)
 
+{- |The 'getModificationTime' operation returns the
+clock time at which the file or directory was last modified.
+
+The operation may fail with:
+
+* 'isPermissionError' if the user is not permitted to access
+  the modification time; or
+
+* 'isDoesNotExistError' if the file or directory does not exist.
+
+-}
+
 getModificationTime :: FilePath -> IO ClockTime
 getModificationTime name =
- withFileStatus name $ \ st ->
+ withFileStatus "getModificationTime" name $ \ st ->
  modificationTime st
 
-withFileStatus :: FilePath -> (Ptr CStat -> IO a) -> IO a
-withFileStatus name f = do
+withFileStatus :: String -> FilePath -> (Ptr CStat -> IO a) -> IO a
+withFileStatus loc name f = do
   modifyIOError (`ioeSetFileName` name) $
     allocaBytes sizeof_stat $ \p ->
       withCString (fileNameEndClean name) $ \s -> do
-        throwErrnoIfMinus1Retry_ "withFileStatus" (c_stat s p)
+        throwErrnoIfMinus1Retry_ loc (c_stat s p)
        f p
 
-withFileOrSymlinkStatus :: FilePath -> (Ptr CStat -> IO a) -> IO a
-withFileOrSymlinkStatus name f = do
+withFileOrSymlinkStatus :: String -> FilePath -> (Ptr CStat -> IO a) -> IO a
+withFileOrSymlinkStatus loc name f = do
   modifyIOError (`ioeSetFileName` name) $
     allocaBytes sizeof_stat $ \p ->
       withCString name $ \s -> do
-        throwErrnoIfMinus1Retry_ "withFileOrSymlinkStatus" (lstat s p)
+        throwErrnoIfMinus1Retry_ loc (lstat s p)
        f p
 
 modificationTime :: Ptr CStat -> IO ClockTime