{-# LANGUAGE CPP, GADTs, DataKinds, KindSignatures, StandaloneDeriving, RankNTypes, DeriveDataTypeable, FlexibleInstances, MagicHash #-}
module Data.FilePath
( Path(..)
, From(..)
, PathSegment
, segString
, mkPathSegment
, FilePath
, (</>)
, rootPath
, relativePath
, mkDirPath
, mkDirPathSeg
, mkFilePath
, mkFilePathSeg
, mkRootFilePathBase
, mkFullFilePath
, dirname
, basename
, basenameSeg
, showp
, segQ
, dirpathQ
, filepathQ
) where
import Prelude hiding (FilePath)
import Data.Data
import Data.Char
import Data.List.Split
import Data.Maybe (fromJust)
import Data.Semigroup ( Semigroup(..) )
import Language.Haskell.TH
import Language.Haskell.TH.Quote
import GHC.Types
-- | A PathSegment is any single element of a path...i.e. the stuff between
-- two \'\/\' characters. Valid path segments cannot contain \'\/\' or control
-- characters. PathSegments are also monoids to allow mappending with
-- prefixes/suffixes.
newtype PathSegment = PathSegment { _segString :: String }
deriving (Eq,Show,Typeable,Data)
instance Semigroup PathSegment where
(PathSegment a) <> (PathSegment b) = PathSegment $ a <> b
-- For the motivation behind taking the time and characters to write `segString` instead of just exporting `_segString` pls see <https://github.com/maxpow4h/data-filepath/pull/6>
-- |
-- Every `PathSegment` is a valid string
--
segString :: PathSegment -> String
segString = _segString
-- | Smart constructor for valid PathSegments. Valid path segments cannot
-- contain front slashes or control characters.
-- This function performs __all__ the checks up front.
--
-- * Is the string non-empty?
-- * Does the string contain forward slashes or control characters?
--
mkPathSegment :: String -> Maybe PathSegment
mkPathSegment s
| any (\x -> x == '/' || isControl x) s = Nothing
| null s = Nothing
| otherwise = Just $ PathSegment s
data Path = File | Directory
data From = Root | Relative
data FilePath (a :: From) (b :: Path) where
RootPath :: FilePath Root Directory
RelativePath :: FilePath Relative Directory
FilePath :: FilePath a Directory -> PathSegment -> FilePath a File
DirectoryPath :: FilePath a Directory -> PathSegment -> FilePath a Directory
-- Path API
rootPath :: FilePath Root Directory
rootPath = RootPath
relativePath :: FilePath Relative Directory
relativePath = RelativePath
infixr 5 </>
(</>) :: FilePath a Directory -> FilePath Relative b -> FilePath a b
p </> RelativePath = p
p </> (DirectoryPath u s) = DirectoryPath (p </> u) s
p </> (FilePath u s) = FilePath (p </> u) s
-- | Smart constructor for directories. Valid directories must be valid
-- PathSegments and also cannot be empty strings.
mkDirPath :: String -> Maybe (FilePath Relative Directory)
mkDirPath = fmap mkDirPathSeg . mkPathSegment
-- | This function basically defines what the `PathSegment` type is semantically.
-- It is string like thing which you can safely create a path from.
-- See `mkPathSegment`, `mkFilePathSeg`
--
mkDirPathSeg :: PathSegment -> FilePath Relative Directory
mkDirPathSeg = DirectoryPath relativePath
-- | Smart constructor for files. Valid files must be valid PathSegments and
-- also cannot be empty strings.
mkFilePath :: String -> Maybe (FilePath Relative File)
mkFilePath = fmap mkFilePathSeg . mkPathSegment
mkFilePathSeg :: PathSegment -> FilePath Relative File
mkFilePathSeg = FilePath relativePath
mkRootFilePathBase :: String -> Maybe (FilePath Root Directory)
mkRootFilePathBase ('/':s) = do
ys <- xs
return $ foldl (</>) RootPath ys
where
ss = splitOn "/" s
xs = mapM mkDirPath $ filter (not . null) ss
mkRootFilePathBase _ = Nothing -- all full file paths must start from /
mkFullFilePath :: String -> Maybe (FilePath Root File)
mkFullFilePath ('/':s) = do
y <- x
ys <- xs
return $ foldl (</>) RootPath ys </> y
where
ss = splitOn "/" s
xs = mapM mkDirPath $ init ss
x = mkFilePath $ last ss
mkFullFilePath _ = Nothing -- all full file paths must start from /
dirname :: FilePath a File -> FilePath a Directory
dirname (FilePath dir _) = dir
basename :: FilePath a File -> String
basename (FilePath _ (PathSegment bname)) = bname
basenameSeg :: FilePath a File -> PathSegment
basenameSeg (FilePath _ bname) = bname
showp :: FilePath a b -> String
showp RootPath = ""
showp RelativePath = "."
showp (DirectoryPath u (PathSegment s)) = showp u ++ "/" ++ s
showp (FilePath u (PathSegment s)) = showp u ++ "/" ++ s
-- TODO: could it split the delimiters?
segQ :: QuasiQuoter
segQ = QuasiQuoter qExp qPat (error "path segments are not types") (error "path segments are not decs")
where
qExp :: String -> ExpQ
qExp s = dataToExpQ (const Nothing) (fromJust (mkPathSegment s) :: PathSegment)
qPat = undefined
-- TODO: could it split the delimiters?
dirpathQ :: QuasiQuoter
dirpathQ = QuasiQuoter qExp qPat (error "dir paths are not types") (error "dir paths are not decs")
where
qExp :: String -> ExpQ
qExp s = dataToExpQ (const Nothing) (fromJust (mkDirPath s) :: FilePath Relative Directory)
qPat = undefined
filepathQ :: QuasiQuoter
filepathQ = QuasiQuoter qExp qPat (error "file paths are not types") (error "file paths are not decs")
where
qExp :: String -> ExpQ
qExp s = dataToExpQ (const Nothing) (fromJust (mkFilePath s) :: FilePath Relative File)
qPat = undefined
-- data / typeable
-- deriving instance Show (FilePath a b)
instance Show (FilePath a b) where
show = showp
instance Data
(FilePath
Relative Directory) where
gfoldl _k_aFi z_aFj RelativePath
= z_aFj RelativePath
gfoldl
k_aFo
z_aFp
(DirectoryPath a1_aFq a2_aFr)
= (z_aFp DirectoryPath `k_aFo` a1_aFq)
`k_aFo` a2_aFr
gunfold k_aFs z_aFt c_aFu
= case constrIndex c_aFu of
GHC.Types.I# 2# -> z_aFt RelativePath
GHC.Types.I# 4# -> k_aFs (k_aFs (z_aFt DirectoryPath))
_ -> error "impossible"
toConstr RelativePath
= cRelativePath
toConstr (DirectoryPath _ _)
= cDirectoryPath
dataTypeOf _ = tFilePath
instance Data
(FilePath
Root Directory) where
gfoldl _k_aFv z_aFw RootPath
= z_aFw RootPath
gfoldl
k_aFD
z_aFE
(DirectoryPath a1_aFF a2_aFG)
= (z_aFE DirectoryPath `k_aFD` a1_aFF)
`k_aFD` a2_aFG
gunfold k_aFH z_aFI c_aFJ
= case constrIndex c_aFJ of
GHC.Types.I# 1# -> z_aFI RootPath
GHC.Types.I# 4# -> k_aFH (k_aFH (z_aFI DirectoryPath))
_ -> error "impossible"
toConstr RootPath
= cRootPath
toConstr (DirectoryPath _ _)
= cDirectoryPath
dataTypeOf _ = tFilePath
instance Data
(FilePath
Relative File) where
gfoldl k_aFO z_aFP (FilePath a1_aFQ a2_aFR)
= (z_aFP FilePath `k_aFO` a1_aFQ) `k_aFO` a2_aFR
gunfold k_aFW z_aFX c_aFY
= case constrIndex c_aFY of
GHC.Types.I# 3# -> k_aFW (k_aFW (z_aFX FilePath))
_ -> error "impossible"
toConstr (FilePath _ _)
= cFilePath
dataTypeOf _ = tFilePath
instance Data
(FilePath Root File) where
gfoldl k_aG3 z_aG4 (FilePath a1_aG5 a2_aG6)
= (z_aG4 FilePath `k_aG3` a1_aG5) `k_aG3` a2_aG6
gunfold k_aGb z_aGc c_aGd
= case constrIndex c_aGd of
GHC.Types.I# 3# -> k_aGb (k_aGb (z_aGc FilePath))
_ -> error "impossible"
toConstr (FilePath _ _)
= cFilePath
dataTypeOf _ = tFilePath
tFilePath :: DataType
cRootPath :: Constr
cRelativePath :: Constr
cFilePath :: Constr
cDirectoryPath :: Constr
tFilePath
= mkDataType
"FilePath"
[cRootPath, cRelativePath,
cFilePath, cDirectoryPath]
cRootPath
= mkConstr
tFilePath "RootPath" [] Prefix
cRelativePath
= mkConstr
tFilePath "RelativePath" [] Prefix
cFilePath
= mkConstr
tFilePath "FilePath" [] Prefix
cDirectoryPath
= mkConstr
tFilePath "DirectoryPath" [] Prefix
#if __GLASGOW_HASKELL__ == 706
{-# NOINLINE fTyCon #-}
fTyCon :: TyCon
fTyCon = mkTyCon3 "main" "Data.FilePath" "FilePath"
instance Typeable (FilePath Relative Directory) where
typeOf _ = mkTyConApp fTyCon []
instance Typeable (FilePath Root Directory) where
typeOf _ = mkTyConApp fTyCon []
instance Typeable (FilePath Relative File) where
typeOf _ = mkTyConApp fTyCon []
instance Typeable (FilePath Root File) where
typeOf _ = mkTyConApp fTyCon []
#endif
#if __GLASGOW_HASKELL__ == 708 || __GLASGOW_HASKELL__ == 710
deriving instance Typeable Directory
deriving instance Typeable Relative
deriving instance Typeable Root
deriving instance Typeable File
deriving instance Typeable FilePath
#endif