----------------------------------------------------------------------------- -- | -- Module : System.FilePath.Lens -- Copyright : (C) 2012-14 Edward Kmett -- License : BSD-style (see the file LICENSE) -- Maintainer : Edward Kmett <ekmett@gmail.com> -- Stability : experimental -- Portability : Rank2Types -- ---------------------------------------------------------------------------- module System.FilePath.Lens ( -- * Operators (</>~), (<</>~), (<<</>~), (<.>~), (<<.>~), (<<<.>~) , (</>=), (<</>=), (<<</>=), (<.>=), (<<.>=), (<<<.>=) -- * Lenses , basename, directory, extension, filename ) where import Control.Applicative ((<$>)) import Control.Monad.State as State import System.FilePath ( (</>), (<.>), splitExtension , takeBaseName, takeDirectory , takeExtension, takeFileName ) import Control.Lens hiding ((<.>)) -- $setup -- >>> :set -XNoOverloadedStrings infixr 4 </>~, <</>~, <<</>~, <.>~, <<.>~, <<<.>~ infix 4 </>=, <</>=, <<</>=, <.>=, <<.>=, <<<.>= -- | Modify the path by adding another path. -- -- >>> both </>~ "bin" $ ("hello","world") -- ("hello/bin","world/bin") -- -- @ -- ('</>~') :: 'Setter' s a 'FilePath' 'FilePath' -> 'FilePath' -> s -> a -- ('</>~') :: 'Iso' s a 'FilePath' 'FilePath' -> 'FilePath' -> s -> a -- ('</>~') :: 'Lens' s a 'FilePath' 'FilePath' -> 'FilePath' -> s -> a -- ('</>~') :: 'Traversal' s a 'FilePath' 'FilePath' -> 'FilePath' -> s -> a -- @ (</>~) :: ASetter s t FilePath FilePath -> FilePath -> s -> t l </>~ n = over l (</> n) {-# INLINE (</>~) #-} -- | Modify the target(s) of a 'Simple' 'Lens', 'Iso', 'Setter' or 'Traversal' by adding a path. -- -- >>> execState (both </>= "bin") ("hello","world") -- ("hello/bin","world/bin") -- -- @ -- ('</>=') :: 'MonadState' s m => 'Setter'' s 'FilePath' -> 'FilePath' -> m () -- ('</>=') :: 'MonadState' s m => 'Iso'' s 'FilePath' -> 'FilePath' -> m () -- ('</>=') :: 'MonadState' s m => 'Lens'' s 'FilePath' -> 'FilePath' -> m () -- ('</>=') :: 'MonadState' s m => 'Traversal'' s 'FilePath' -> 'FilePath' -> m () -- @ (</>=) :: MonadState s m => ASetter' s FilePath -> FilePath -> m () l </>= b = State.modify (l </>~ b) {-# INLINE (</>=) #-} -- | Add a path onto the end of the target of a 'Lens' and return the result -- -- When you do not need the result of the operation, ('</>~') is more flexible. (<</>~) :: LensLike ((,)FilePath) s a FilePath FilePath -> FilePath -> s -> (FilePath, a) l <</>~ m = l <%~ (</> m) {-# INLINE (<</>~) #-} -- | Add a path onto the end of the target of a 'Lens' into -- your monad's state and return the result. -- -- When you do not need the result of the operation, ('</>=') is more flexible. (<</>=) :: MonadState s m => LensLike' ((,)FilePath) s FilePath -> FilePath -> m FilePath l <</>= r = l <%= (</> r) {-# INLINE (<</>=) #-} (<<</>~) :: Optical' (->) q ((,)FilePath) s FilePath -> FilePath -> q s (FilePath, s) l <<</>~ b = l $ \a -> (a, a </> b) {-# INLINE (<<</>~) #-} (<<</>=) :: MonadState s m => LensLike' ((,)FilePath) s FilePath -> FilePath -> m FilePath l <<</>= b = l %%= \a -> (a, a </> b) {-# INLINE (<<</>=) #-} -- | Modify the path by adding extension. -- -- >>> both <.>~ "txt" $ ("hello","world") -- ("hello.txt","world.txt") -- -- @ -- ('<.>~') :: 'Setter' s a 'FilePath' 'FilePath' -> 'String' -> s -> a -- ('<.>~') :: 'Iso' s a 'FilePath' 'FilePath' -> 'String' -> s -> a -- ('<.>~') :: 'Lens' s a 'FilePath' 'FilePath' -> 'String' -> s -> a -- ('<.>~') :: 'Traversal' s a 'FilePath' 'FilePath' -> 'String' -> s -> a -- @ (<.>~) :: ASetter s a FilePath FilePath -> String -> s -> a l <.>~ n = over l (<.> n) {-# INLINE (<.>~) #-} -- | Modify the target(s) of a 'Simple' 'Lens', 'Iso', 'Setter' or 'Traversal' by adding an extension. -- -- >>> execState (both <.>= "txt") ("hello","world") -- ("hello.txt","world.txt") -- -- @ -- ('<.>=') :: 'MonadState' s m => 'Setter'' s 'FilePath' -> 'String' -> m () -- ('<.>=') :: 'MonadState' s m => 'Iso'' s 'FilePath' -> 'String' -> m () -- ('<.>=') :: 'MonadState' s m => 'Lens'' s 'FilePath' -> 'String' -> m () -- ('<.>=') :: 'MonadState' s m => 'Traversal'' s 'FilePath' -> 'String' -> m () -- @ (<.>=) :: MonadState s m => ASetter' s FilePath -> String -> m () l <.>= b = State.modify (l <.>~ b) {-# INLINE (<.>=) #-} -- | Add an extension onto the end of the target of a 'Lens' and return the result -- -- >>> _1 <<.>~ "txt" $ ("hello","world") -- ("hello.txt",("hello.txt","world")) -- -- When you do not need the result of the operation, ('<.>~') is more flexible. (<<.>~) :: LensLike ((,)FilePath) s a FilePath FilePath -> String -> s -> (FilePath, a) l <<.>~ m = l <%~ (<.> m) {-# INLINE (<<.>~) #-} -- | Add an extension onto the end of the target of a 'Lens' into -- your monad's state and return the result. -- -- >>> evalState (_1 <<.>= "txt") ("hello","world") -- "hello.txt" -- -- When you do not need the result of the operation, ('<.>=') is more flexible. (<<.>=) :: MonadState s m => LensLike' ((,)FilePath) s FilePath -> String -> m FilePath l <<.>= r = l <%= (<.> r) {-# INLINE (<<.>=) #-} (<<<.>~) :: Optical' (->) q ((,)FilePath) s FilePath -> String -> q s (FilePath, s) l <<<.>~ b = l $ \a -> (a, a <.> b) {-# INLINE (<<<.>~) #-} (<<<.>=) :: MonadState s m => LensLike' ((,)FilePath) s FilePath -> String -> m FilePath l <<<.>= b = l %%= \a -> (a, a <.> b) {-# INLINE (<<<.>=) #-} -- | A 'Lens' for reading and writing to the basename -- -- Note: This is 'not' a legal 'Lens' unless the outer 'FilePath' has both a directory -- and filename component and the generated basenames are not null and contain no directory -- separators. -- -- >>> basename .~ "filename" $ "path/name.png" -- "path/filename.png" basename :: Lens' FilePath FilePath basename f p = (<.> takeExtension p) . (takeDirectory p </>) <$> f (takeBaseName p) {-# INLINE basename #-} -- | A 'Lens' for reading and writing to the directory -- -- Note: this is /not/ a legal 'Lens' unless the outer 'FilePath' already has a directory component, -- and generated directories are not null. -- -- >>> "long/path/name.txt" ^. directory -- "long/path" directory :: Lens' FilePath FilePath directory f p = (</> takeFileName p) <$> f (takeDirectory p) {-# INLINE directory #-} -- | A 'Lens' for reading and writing to the extension -- -- Note: This is /not/ a legal 'Lens', unless you are careful to ensure that generated -- extension 'FilePath' components are either null or start with 'System.FilePath.extSeparator' -- and do not contain any internal 'System.FilePath.extSeparator's. -- -- >>> extension .~ ".png" $ "path/name.txt" -- "path/name.png" extension :: Lens' FilePath FilePath extension f p = (n <.>) <$> f e where (n, e) = splitExtension p {-# INLINE extension #-} -- | A 'Lens' for reading and writing to the full filename -- -- Note: This is /not/ a legal 'Lens', unless you are careful to ensure that generated -- filename 'FilePath' components are not null and do not contain any -- elements of 'System.FilePath.pathSeparators's. -- -- >>> filename .~ "name.txt" $ "path/name.png" -- "path/name.txt" filename :: Lens' FilePath FilePath filename f p = (takeDirectory p </>) <$> f (takeFileName p) {-# INLINE filename #-}