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GHC 10.0.0.20260917 · lts/ghc-10.0.x · 2b27632 · 2026-10-31

Modulefilepath-1.5.5.0Haskell2010

System.OsPath.Windows

Contents
  1. Types
  2. Filepath construction
  3. Filepath deconstruction
  4. Word construction
  5. Word deconstruction
  6. Separator predicates
  7. $PATH methods
  8. Extension functions
  9. Filename/directory functions
  10. Drive functions
  11. Trailing slash functions
  12. File name manipulations
Synopsis
  • Packagefilepath-1.5.5.0
  • Exports66
  • LanguageHaskell2010
  • LicenceBSD-3-Clause
  • SourceTypes.hs

Types

newtypenewtype WindowsString
Source#

Commonly used windows string as wide character bytes.

Instances9Eq, Ord, Show, Generic, Semigroup, Monoid, …
newtypenewtype WindowsChar
Source#

This represents a "wide char" on windows.

A better name would maybe have been WindowsWord, since this is just Word16 in a UCS-2 sequence.

Instances7Eq, Ord, Show, Generic, NFData, Lift, …

Filepath construction

valuepack :: [WindowsChar] -> WindowsString
Source#

Pack a list of platform words to a platform string.

Note that using this in conjunction with unsafeFromChar to convert from [Char] to platform string is probably not what you want, because it will truncate unicode code points.

Additionally, a platform word is a byte (or wide char on windows) in an encoded byte sequence, so we're not operating on unicode code points or graphemes here.

Filepath deconstruction

Word construction

valueunsafeFromChar :: Char -> WindowsChar
Source#

Truncates to 2 octets.

Note that WindowsChar is a "wide char" in a UCS-2 encoded byte sequence and is not morally a unicode code point by any means, so this conversion is rarely what you want.

Consider using fromWord instead.

Word deconstruction

Separator predicates

$PATH methods

valuesplitSearchPath :: WindowsString -> [WindowsPath]
Source#

Take a string, split it on the searchPathSeparator character.

Blank items are ignored and path elements are stripped of quotes.

splitSearchPath "File1;File2;File3"  == ["File1","File2","File3"]
splitSearchPath "File1;;File2;File3" == ["File1","File2","File3"]
splitSearchPath "File1;\"File2\";File3" == ["File1","File2","File3"]

Extension functions

valuesplitExtension :: WindowsPath -> (WindowsPath, WindowsString)
Source#

Split on the extension. addExtension is the inverse.

splitExtension "/directory/path.ext" == ("/directory/path",".ext")
uncurry (<>) (splitExtension x) == x
Valid x => uncurry addExtension (splitExtension x) == x
splitExtension "file.txt" == ("file",".txt")
splitExtension "file" == ("file","")
splitExtension "file/file.txt" == ("file/file",".txt")
splitExtension "file.txt/boris" == ("file.txt/boris","")
splitExtension "file.txt/boris.ext" == ("file.txt/boris",".ext")
splitExtension "file/path.txt.bob.fred" == ("file/path.txt.bob",".fred")
splitExtension "file/path.txt/" == ("file/path.txt/","")
valuetakeExtension :: WindowsPath -> WindowsString
Source#

Get the extension of a file, returns "" for no extension, .ext otherwise.

takeExtension "/directory/path.ext" == ".ext"
takeExtension x == snd (splitExtension x)
Valid x => takeExtension (addExtension x "ext") == ".ext"
Valid x => takeExtension (replaceExtension x "ext") == ".ext"
valuereplaceExtension :: WindowsPath -> WindowsString -> WindowsPath
Source#

Set the extension of a file, overwriting one if already present, equivalent to -<.>.

replaceExtension "/directory/path.txt" "ext" == "/directory/path.ext"
replaceExtension "/directory/path.txt" ".ext" == "/directory/path.ext"
replaceExtension "file.txt" ".bob" == "file.bob"
replaceExtension "file.txt" "bob" == "file.bob"
replaceExtension "file" ".bob" == "file.bob"
replaceExtension "file.txt" "" == "file"
replaceExtension "file.fred.bob" "txt" == "file.fred.txt"
replaceExtension x y == addExtension (dropExtension x) y
valueaddExtension :: WindowsPath -> WindowsString -> WindowsPath
Source#

Add an extension, even if there is already one there, equivalent to <.>.

addExtension "/directory/path" "ext" == "/directory/path.ext"
addExtension "file.txt" "bib" == "file.txt.bib"
addExtension "file." ".bib" == "file..bib"
addExtension "file" ".bib" == "file.bib"
addExtension "/" "x" == "/.x"
addExtension x "" == x
Valid x => takeFileName (addExtension (addTrailingPathSeparator x) "ext") == ".ext"
Windows: addExtension "\\\\share" ".txt" == "\\\\share\\.txt"

Add an extension, even if there is already one there, equivalent to <.>.

addExtension "/directory/path" "ext" == "/directory/path.ext"
addExtension "file.txt" "bib" == "file.txt.bib"
addExtension "file." ".bib" == "file..bib"
addExtension "file" ".bib" == "file.bib"
addExtension "/" "x" == "/.x"
addExtension x "" == x
Valid x => takeFileName (addExtension (addTrailingPathSeparator x) "ext") == ".ext"
addExtension "\\\\share" ".txt" == "\\\\share\\.txt"
valuehasExtension :: WindowsPath -> Bool
Source#

Does the given filename have an extension?

hasExtension "/directory/path.ext" == True
hasExtension "/directory/path" == False
null (takeExtension x) == not (hasExtension x)
valuesplitExtensions :: WindowsPath -> (WindowsPath, WindowsString)
Source#

Split on all extensions.

splitExtensions "/directory/path.ext" == ("/directory/path",".ext")
splitExtensions "file.tar.gz" == ("file",".tar.gz")
uncurry (<>) (splitExtensions x) == x
Valid x => uncurry addExtension (splitExtensions x) == x
splitExtensions "file.tar.gz" == ("file",".tar.gz")
valuedropExtensions :: WindowsPath -> WindowsPath
Source#

Drop all extensions.

dropExtensions "/directory/path.ext" == "/directory/path"
dropExtensions "file.tar.gz" == "file"
not $ hasExtension $ dropExtensions x
not $ any isExtSeparator $ takeFileName $ dropExtensions x
valueisExtensionOf :: WindowsString -> WindowsPath -> Bool
Source#

Does the given filename have the specified extension?

"png" `isExtensionOf` "/directory/file.png" == True
".png" `isExtensionOf` "/directory/file.png" == True
".tar.gz" `isExtensionOf` "bar/foo.tar.gz" == True
"ar.gz" `isExtensionOf` "bar/foo.tar.gz" == False
"png" `isExtensionOf` "/directory/file.png.jpg" == False
"csv/table.csv" `isExtensionOf` "/data/csv/table.csv" == False
valuestripExtension :: WindowsString -> WindowsPath -> Maybe WindowsPath
Source#

Drop the given extension from a filepath, and the "." preceding it. Returns Nothing if the filepath does not have the given extension, or Just and the part before the extension if it does.

This function can be more predictable than dropExtensions, especially if the filename might itself contain . characters.

stripExtension "hs.o" "foo.x.hs.o" == Just "foo.x"
stripExtension "hi.o" "foo.x.hs.o" == Nothing
dropExtension x == fromJust (stripExtension (takeExtension x) x)
dropExtensions x == fromJust (stripExtension (takeExtensions x) x)
stripExtension ".c.d" "a.b.c.d"  == Just "a.b"
stripExtension ".c.d" "a.b..c.d" == Just "a.b."
stripExtension "baz"  "foo.bar"  == Nothing
stripExtension "bar"  "foobar"   == Nothing
stripExtension ""     x          == Just x

Filename/directory functions

valuesplitFileName :: WindowsPath -> (WindowsPath, WindowsPath)
Source#

Split a filename into directory and file. </> is the inverse. The first component will often end with a trailing slash.

splitFileName "/directory/file.ext" == ("/directory/","file.ext")
Valid x => uncurry (</>) (splitFileName x) == x || fst (splitFileName x) == "./"
Valid x => isValid (fst (splitFileName x))
splitFileName "file/bob.txt" == ("file/", "bob.txt")
splitFileName "file/" == ("file/", "")
splitFileName "bob" == ("./", "bob")
splitFileName "c:" == ("c:","")
valuetakeFileName :: WindowsPath -> WindowsPath
Source#

Get the file name.

takeFileName "/directory/file.ext" == "file.ext"
takeFileName "test/" == ""
takeFileName x `isSuffixOf` x
takeFileName x == snd (splitFileName x)
Valid x => takeFileName (replaceFileName x "fred") == "fred"
Valid x => takeFileName (x </> "fred") == "fred"
Valid x => isRelative (takeFileName x)
valuetakeBaseName :: WindowsPath -> WindowsPath
Source#

Get the base name, without an extension or path.

takeBaseName "/directory/file.ext" == "file"
takeBaseName "file/test.txt" == "test"
takeBaseName "dave.ext" == "dave"
takeBaseName "" == ""
takeBaseName "test" == "test"
takeBaseName (addTrailingPathSeparator x) == ""
takeBaseName "file/file.tar.gz" == "file.tar"
valuereplaceBaseName :: WindowsPath -> WindowsString -> WindowsPath
Source#

Set the base name.

replaceBaseName "/directory/other.ext" "file" == "/directory/file.ext"
replaceBaseName "file/test.txt" "bob" == "file/bob.txt"
replaceBaseName "fred" "bill" == "bill"
replaceBaseName "/dave/fred/bob.gz.tar" "new" == "/dave/fred/new.tar"
Valid x => replaceBaseName x (takeBaseName x) == x
valuetakeDirectory :: WindowsPath -> WindowsPath
Source#

Get the directory name, move up one level.

takeDirectory "/directory/other.ext" == "/directory"
takeDirectory x `isPrefixOf` x || takeDirectory x == "."
takeDirectory "foo" == "."
takeDirectory "/" == "/"
takeDirectory "/foo" == "/"
takeDirectory "/foo/bar/baz" == "/foo/bar"
takeDirectory "/foo/bar/baz/" == "/foo/bar/baz"
takeDirectory "foo/bar/baz" == "foo/bar"
takeDirectory "foo\\bar" == "foo"
takeDirectory "foo\\bar\\\\" == "foo\\bar"
takeDirectory "C:\\" == "C:\\"
value(</>) :: WindowsPath -> WindowsPath -> WindowsPath
Source#

Combine two paths with a path separator. If the second path starts with a path separator or a drive letter, then it returns the second. The intention is that readFile (dir </> file) will access the same file as setCurrentDirectory dir; readFile file.

"/directory" </> "file.ext" == "/directory\\file.ext"
"directory" </> "/file.ext" == "/file.ext"
Valid x => (takeDirectory x </> takeFileName x) `equalFilePath` x

Combined:

"C:\\foo" </> "bar" == "C:\\foo\\bar"
"home" </> "bob" == "home\\bob"

Not combined:

"home" </> "C:\\bob" == "C:\\bob"

Not combined (tricky):

If a filepath starts with a single slash, it is relative to the root of the current drive. In [1], this is (confusingly) referred to as an absolute path. The current behavior of </> is to never combine these forms.

"home" </> "/bob" == "/bob"
"home" </> "\\bob" == "\\bob"
"C:\\home" </> "\\bob" == "\\bob"

From [1]: "If a file name begins with only a disk designator but not the backslash after the colon, it is interpreted as a relative path to the current directory on the drive with the specified letter." The current behavior of </> is to never combine these forms.

"D:\\foo" </> "C:bar" == "C:bar"
"C:\\foo" </> "C:bar" == "C:bar"
valuesplitPath :: WindowsPath -> [WindowsPath]
Source#

Split a path by the directory separator.

splitPath "/directory/file.ext" == ["/","directory/","file.ext"]
concat (splitPath x) == x
splitPath "test//item/" == ["test//","item/"]
splitPath "test/item/file" == ["test/","item/","file"]
splitPath "" == []
splitPath "c:\\test\\path" == ["c:\\","test\\","path"]
valuejoinPath :: [WindowsPath] -> WindowsPath
Source#

Join path elements back together.

joinPath z == foldr (</>) "" z
joinPath ["/","directory/","file.ext"] == "/directory/file.ext"
Valid x => joinPath (splitPath x) == x
joinPath [] == ""
valuesplitDirectories :: WindowsPath -> [WindowsPath]
Source#

Just as splitPath, but don't add the trailing slashes to each element.

splitDirectories "/directory/file.ext" == ["/","directory","file.ext"]
splitDirectories "test/file" == ["test","file"]
splitDirectories "/test/file" == ["/","test","file"]
splitDirectories "C:\\test\\file" == ["C:\\", "test", "file"]
Valid x => joinPath (splitDirectories x) `equalFilePath` x
splitDirectories "" == []
splitDirectories "C:\\test\\\\\\file" == ["C:\\", "test", "file"]
splitDirectories "/test///file" == ["/","test","file"]

Drive functions

valuesplitDrive :: WindowsPath -> (WindowsPath, WindowsPath)
Source#

Split a path into a drive and a path.

uncurry (<>) (splitDrive x) == x
splitDrive "file" == ("","file")
splitDrive "c:/file" == ("c:/","file")
splitDrive "c:\\file" == ("c:\\","file")
splitDrive "\\\\shared\\test" == ("\\\\shared\\","test")
splitDrive "\\\\shared" == ("\\\\shared","")
splitDrive "\\\\?\\UNC\\shared\\file" == ("\\\\?\\UNC\\shared\\","file")
splitDrive "\\\\?\\UNCshared\\file" == ("\\\\?\\","UNCshared\\file")
splitDrive "\\\\?\\d:\\file" == ("\\\\?\\d:\\","file")
splitDrive "/d" == ("","/d")
valuejoinDrive :: WindowsPath -> WindowsPath -> WindowsPath
Source#

Join a drive and the rest of the path.

Valid x => uncurry joinDrive (splitDrive x) == x
Windows: joinDrive "C:" "foo" == "C:foo"
Windows: joinDrive "C:\\" "bar" == "C:\\bar"
Windows: joinDrive "\\\\share" "foo" == "\\\\share\\foo"
Windows: joinDrive "/:" "foo" == "/:\\foo"

Join a drive and the rest of the path.

Valid x => uncurry joinDrive (splitDrive x) == x
joinDrive "C:" "foo" == "C:foo"
joinDrive "C:\\" "bar" == "C:\\bar"
joinDrive "\\\\share" "foo" == "\\\\share\\foo"
joinDrive "/:" "foo" == "/:\\foo"
valuehasDrive :: WindowsPath -> Bool
Source#

Does a path have a drive.

not (hasDrive x) == null (takeDrive x)
hasDrive "C:\\foo" == True
hasDrive "C:foo" == True
hasDrive "foo" == False
hasDrive "" == False

Trailing slash functions

File name manipulations

valuenormalise :: WindowsPath -> WindowsPath
Source#

Normalise a file

  • // outside of the drive can be made blank

  • / -> pathSeparator

  • ./ -> ""

Does not remove "..", because of symlinks.

normalise "c:\\file/bob\\" == "C:\\file\\bob\\"
normalise "c:\\" == "C:\\"
normalise "C:.\\" == "C:"
normalise "\\\\server\\test" == "\\\\server\\test"
normalise "//server/test" == "\\\\server\\test"
normalise "c:/file" == "C:\\file"
normalise "/file" == "\\file"
normalise "\\" == "\\"
normalise "/./" == "\\"
normalise "." == "."
valueequalFilePath :: WindowsPath -> WindowsPath -> Bool
Source#

Equality of two filepaths. If you call System.Directory.canonicalizePath first this has a much better chance of working. Note that this doesn't follow symlinks or DOSNAM~1s.

Similar to normalise, this does not expand "..", because of symlinks.

x == y ==> equalFilePath x y
normalise x == normalise y ==> equalFilePath x y
equalFilePath "foo" "foo/"
not (equalFilePath "/a/../c" "/c")
not (equalFilePath "foo" "/foo")
equalFilePath "foo" "FOO"
not (equalFilePath "C:" "C:/")
valuemakeRelative :: WindowsPath -> WindowsPath -> WindowsPath
Source#

Contract a filename, based on a relative path. Note that the resulting path will never introduce .. paths, as the presence of symlinks means ../b may not reach a/b if it starts from a/c. For a worked example see this blog post.

The corresponding makeAbsolute function can be found in System.Directory.

makeRelative "/directory" "/directory/file.ext" == "file.ext"
Valid x => makeRelative (takeDirectory x) x `equalFilePath` takeFileName x
makeRelative x x == "."
Valid x y => equalFilePath x y || (isRelative x && makeRelative y x == x) || equalFilePath (y </> makeRelative y x) x
makeRelative "C:\\Home" "c:\\home\\bob" == "bob"
makeRelative "C:\\Home" "c:/home/bob" == "bob"
makeRelative "C:\\Home" "D:\\Home\\Bob" == "D:\\Home\\Bob"
makeRelative "C:\\Home" "C:Home\\Bob" == "C:Home\\Bob"
makeRelative "/Home" "/home/bob" == "bob"
makeRelative "/" "//" == "//"
valueisRelative :: WindowsPath -> Bool
Source#

Is a path relative, or is it fixed to the root?

isRelative "path\\test" == True
isRelative "c:\\test" == False
isRelative "c:test" == True
isRelative "c:\\" == False
isRelative "c:/" == False
isRelative "c:" == True
isRelative "\\\\foo" == False
isRelative "\\\\?\\foo" == False
isRelative "\\\\?\\UNC\\foo" == False
isRelative "/foo" == True
isRelative "\\foo" == True

According to [1]:

  • "A UNC name of any format [is never relative]."

  • "You cannot use the "\?" prefix with a relative path."

valueisValid :: WindowsPath -> Bool
Source#

Is a filepath valid, i.e. could you create a file like it? This function checks for invalid names, and invalid characters, but does not check if length limits are exceeded, as these are typically filesystem dependent.

isValid "" == False
isValid "\0" == False
isValid "c:\\test" == True
isValid "c:\\test:of_test" == False
isValid "test*" == False
isValid "c:\\test\\nul" == False
isValid "c:\\test\\prn.txt" == False
isValid "c:\\nul\\file" == False
isValid "\\\\" == False
isValid "\\\\\\foo" == False
isValid "\\\\?\\D:file" == False
isValid "foo\tbar" == False
isValid "nul .txt" == False
isValid " nul.txt" == True
valuemakeValid :: WindowsPath -> WindowsPath
Source#

Take a filepath and make it valid; does not change already valid filepaths.

isValid (makeValid x)
isValid x ==> makeValid x == x
makeValid "" == "_"
makeValid "file\0name" == "file_name"
makeValid "c:\\already\\/valid" == "c:\\already\\/valid"
makeValid "c:\\test:of_test" == "c:\\test_of_test"
makeValid "test*" == "test_"
makeValid "c:\\test\\nul" == "c:\\test\\nul_"
makeValid "c:\\test\\prn.txt" == "c:\\test\\prn_.txt"
makeValid "c:\\test/prn.txt" == "c:\\test/prn_.txt"
makeValid "c:\\nul\\file" == "c:\\nul_\\file"
makeValid "\\\\\\foo" == "\\\\drive"
makeValid "\\\\?\\D:file" == "\\\\?\\D:\\file"
makeValid "nul .txt" == "nul _.txt"