[project @ 2005-01-11 12:12:36 by ross]

[ghc-base.git] / System / FilePath.hs

diff --git a/System/FilePath.hs b/System/FilePath.hs
index b27dd4f..4ae4a88 100644 (file)
--- a/System/FilePath.hs
+++ b/System/FilePath.hs
@@ -1,3 +1,5 @@
+{-# OPTIONS -fno-implicit-prelude #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  System.FilePath
@@ -24,6 +26,7 @@ module System.FilePath
          , changeFileExt
          , isRootedPath
          , isAbsolutePath
+         , dropAbsolutePrefix
 
          , pathParents
          , commonParent
@@ -36,11 +39,22 @@ module System.FilePath
          , isPathSeparator
          , pathSeparator
          , searchPathSeparator
+
+        -- * Filename extensions
+        , exeExtension
+        , objExtension
+        , dllExtension
          ) where
 
+#ifdef __GLASGOW_HASKELL__
+import GHC.Base
+import GHC.IOBase(FilePath)
+import GHC.Num
+#else
 import Prelude -- necessary to get dependencies right
-
-import Data.List(intersperse)
+#endif
+import Data.Maybe
+import Data.List
 
 --------------------------------------------------------------
 -- * FilePath
@@ -215,6 +229,18 @@ isAbsolutePath (c:_)       | isPathSeparator c = True
 #endif
 isAbsolutePath _ = False
 
+-- | If the function is applied to an absolute path then it returns a
+-- local path obtained by dropping the absolute prefix from the path.
+-- Under Windows the prefix is @\"\\\"@, @\"c:\"@ or @\"c:\\\"@.
+-- Under Unix the prefix is always @\"\/\"@.
+dropAbsolutePrefix :: FilePath -> FilePath
+dropAbsolutePrefix (c:cs) | isPathSeparator c = cs
+#ifdef mingw32_TARGET_OS
+dropAbsolutePrefix (_:':':c:cs) | isPathSeparator c = cs  -- path with drive letter
+dropAbsolutePrefix (_:':':cs)                       = cs
+#endif
+dropAbsolutePrefix cs = cs
+
 -- | Gets this path and all its parents.
 -- The function is useful in case if you want to create 
 -- some file but you aren\'t sure whether all directories 
@@ -347,21 +373,21 @@ mkSearchPath paths = concat (intersperse [searchPathSeparator] paths)
 -- * Separators
 --------------------------------------------------------------
 
--- | Checks whether the character is a valid path separator for the host platform.
--- The valid character is a 'pathSeparator' but since the Windows operating system 
--- also accepts a backslash (\"\\\") the function also checks for \"\/\" on this platform.
+-- | Checks whether the character is a valid path separator for the host
+-- platform. The valid character is a 'pathSeparator' but since the Windows
+-- operating system also accepts a slash (\"\/\") since DOS 2, the function
+-- checks for it on this platform, too.
 isPathSeparator :: Char -> Bool
-isPathSeparator ch =
 #ifdef mingw32_TARGET_OS
-  ch == '/' || ch == '\\'
+isPathSeparator ch = ch == '/' || ch == '\\'
 #else
-  ch == '/'
+isPathSeparator ch = ch == '/'
 #endif
 
--- | Provides a platform-specific character used to separate directory levels in a 
--- path string that reflects a hierarchical file system organization.
--- The separator is a slash (\"\/\") on Unix and Macintosh, and a backslash (\"\\\") on the 
--- Windows operating system.
+-- | Provides a platform-specific character used to separate directory levels in
+-- a path string that reflects a hierarchical file system organization. The
+-- separator is a slash (@\"\/\"@) on Unix and Macintosh, and a backslash
+-- (@\"\\\"@) on the Windows operating system.
 pathSeparator :: Char
 #ifdef mingw32_TARGET_OS
 pathSeparator = '\\'
@@ -369,12 +395,41 @@ pathSeparator = '\\'
 pathSeparator = '/'
 #endif
 
--- | A platform-specific character used to separate search path strings in 
--- environment variables. The separator is a colon (\":\") on Unix and Macintosh, 
--- and a semicolon (\";\") on the Windows operating system.
+-- | A platform-specific character used to separate search path strings in
+-- environment variables. The separator is a colon (@\":\"@) on Unix and
+-- Macintosh, and a semicolon (@\";\"@) on the Windows operating system.
 searchPathSeparator :: Char
 #ifdef mingw32_TARGET_OS
 searchPathSeparator = ';'
 #else
 searchPathSeparator = ':'
 #endif
+
+-- ToDo: This should be determined via autoconf (AC_EXEEXT)
+-- | Extension for executable files
+-- (typically @\"\"@ on Unix and @\"exe\"@ on Windows or OS\/2)
+exeExtension :: String
+#ifdef mingw32_TARGET_OS
+exeExtension = "exe"
+#else
+exeExtension = ""
+#endif
+
+-- ToDo: This should be determined via autoconf (AC_OBJEXT)
+-- | Extension for object files
+-- (typically @\"o\"@ on Unix and @\"obj\"@ on Windows)
+objExtension :: String
+#ifdef mingw32_TARGET_OS
+objExtension = "obj"
+#else
+objExtension = "o"
+#endif
+
+-- | Extension for dynamically linked (or shared) libraries
+-- (typically @\"so\"@ on Unix and @\"dll\"@ on Windows)
+dllExtension :: String
+#ifdef mingw32_TARGET_OS
+dllExtension = "dll"
+#else
+dllExtension = "so"
+#endif