 | directory-tree-0.2.0: A simple directory-like tree datatype, with useful IO functions | Contents | Index |
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| System.Directory.Tree | | Portability | portable | | Stability | experimental | | Maintainer | Brandon Simmons <brandon.m.simmons@gmail.com> |
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| Description |
Provides a simple data structure mirroring a directory tree on the
filesystem, as well as useful functions for reading and writing
file and directory structures in the IO monad.
Errors are caught in a special constructor in the DirTree type.
Defined instances of Functor, Traversable and Foldable allow for
easily operating on a directory of files. For example, you could use
Foldable.foldr to create a hash of the entire contents of a directory.
The AnchoredDirTree type is a simple wrapper for DirTree to keep track
of a base directory context for the DirTree.
Please send me any requests, bugs, or other feedback on this module!
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| Synopsis |
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| Data types for representing directory trees
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| data DirTree a |
| the String in the name field is always a file name, never a full path.
The free type variable is used in the File constructor and can hold Handles,
Strings representing a file's contents or anything else you can think of.
We catch any IO errors in the Failed constructor. an Exception can be
converted to a String with show.
| | Constructors | |  Instances | |
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| data AnchoredDirTree a |
| a simple wrapper to hold a base directory name, which can be either
an absolute or relative path. This lets us give the DirTree a context,
while still letting us store only directory and file NAMES (not full paths)
in the DirTree. (uses an infix constructor; don't be scared)
| | Constructors | | | Instances | |
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| type FileName = String |
| an element in a FilePath:
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| High level IO functions
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| readDirectory :: FilePath -> IO (AnchoredDirTree String) |
| build an AnchoredDirTree, given the path to a directory, opening the files
using readFile.
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| readDirectoryWith :: (FilePath -> IO a) -> FilePath -> IO (AnchoredDirTree a) |
| same as readDirectory but allows us to, for example, use
ByteString.readFile to return a tree of ByteStrings.
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| writeDirectory :: AnchoredDirTree String -> IO () |
| write a DirTree of strings to disk. clobbers files of the same name.
doesn't affect files in the directories (if any already exist) with
different names:
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| writeDirectoryWith :: (FilePath -> a -> IO ()) -> AnchoredDirTree a -> IO () |
| writes the directory structure to disc, then uses the provided function to
write the contents of Files to disc.
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| Lower level functions
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| zipPaths :: AnchoredDirTree a -> DirTree (FilePath, a) |
| tuple up the complete filename with the File contents, by building up the
path, trie-style, from the root. The filepath will be relative to the current
directory.
This allows us to, for example, mapM_ 'uncurry writeFile' over a DirTree of
strings.
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| build :: FilePath -> IO (AnchoredDirTree FilePath) |
| builds a DirTree from the contents of the directory passed to it, saving
the base directory in the Anchored* wrapper. Errors are caught in the tree in
the Failed constructor. The file fields initially are populated with full
paths to the files they are abstracting.
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| openDirectory :: FilePath -> IOMode -> IO (AnchoredDirTree Handle) |
| a simple application of readDirectoryWith openFile:
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| writeJustDirs :: AnchoredDirTree a -> IO () |
| writes the directory structure (not files) of a DirTree to the anchored
directory. can be preparation for writing files:
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| Utility functions
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| Handling failure
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| successful :: DirTree a -> Bool |
| True if there are no Failed constructors in the tree
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| anyFailed :: DirTree a -> Bool |
| True if any Failed constructors in the tree
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| failures :: DirTree a -> [DirTree a] |
| returns a list of Failed constructors only:
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| failedMap :: (FileName -> IOException -> DirTree a) -> DirTree a -> DirTree a |
| maps a function to convert Failed DirTrees to Files or Dirs
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| Misc.
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| free :: AnchoredDirTree a -> DirTree a |
| strips away base directory wrapper:
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| Produced by Haddock version 2.7.2 |