Storage.Hashed.AnchoredPath

This module implements relative paths within a Tree. All paths are anchored at a certain root (this is usually the Tree root). They are represented by a list of Names (these are just strict bytestrings).

Documentation

newtype Name

Constructors

Name ByteString

Instances

Eq Name

Ord Name

Show Name

newtype AnchoredPath

This is a type of sane file paths. These are always canonic in the sense that there are no stray slashes, no .. components and similar. They are usually used to refer to a location within a Tree, but a relative filesystem path works just as well. These are either constructed from individual name components (using appendPath, catPaths and makeName), or converted from a FilePath (floatPath -- but take care when doing that) or .

Constructors

AnchoredPath [Name]

Instances

Eq AnchoredPath

Ord AnchoredPath

Show AnchoredPath

anchoredRoot :: AnchoredPath

appendPath :: AnchoredPath -> Name -> AnchoredPath

Append an element to the end of a path.

anchorPath :: FilePath -> AnchoredPath -> FilePath

Take a root directory and an anchored path and produce a full FilePath. Moreover, you can use anchorPath "" to get a relative FilePath.

isPrefix :: AnchoredPath -> AnchoredPath -> Bool

Check whether a path is a prefix of another path.

parent :: AnchoredPath -> AnchoredPath

Get parent (path) of a given path. foobarbaz -> foo/bar

parents :: AnchoredPath -> [AnchoredPath]

List all parents of a given path. foobarbaz -> [foo, foo/bar]

catPaths :: AnchoredPath -> AnchoredPath -> AnchoredPath

Catenate two paths together. Not very safe, but sometimes useful (e.g. when you are representing paths relative to a different point than a Tree root).

flatten :: AnchoredPath -> ByteString

makeName :: String -> Name

Unsafe functions.

floatBS :: ByteString -> AnchoredPath

Unsafe. Only ever use on bytestrings that came from flatten on a pre-existing AnchoredPath.

floatPath :: FilePath -> AnchoredPath

Take a relative FilePath and turn it into an AnchoredPath. The operation is (relatively) unsafe. Basically, by using floatPath, you are testifying that the argument is a path relative to some common root -- i.e. the root of the associated Tree object. Also, there are certain invariants about AnchoredPath that this function tries hard to preserve, but probably cannot guarantee (i.e. this is a best-effort thing). You should sanitize any FilePaths before you declare them good by converting into AnchoredPath (using this function).