darcs-2.10.2: a distributed, interactive, smart revision control system

Safe HaskellSafe




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).



newtype Name Source


Name ByteString 

newtype AnchoredPath Source

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 .


AnchoredPath [Name] 

appendPath :: AnchoredPath -> Name -> AnchoredPath Source

Append an element to the end of a path.

anchorPath :: FilePath -> AnchoredPath -> FilePath Source

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 Source

Check whether a path is a prefix of another path.

parent :: AnchoredPath -> AnchoredPath Source

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

parents :: AnchoredPath -> [AnchoredPath] Source

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

catPaths :: AnchoredPath -> AnchoredPath -> AnchoredPath Source

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).

appendToName :: AnchoredPath -> String -> AnchoredPath Source

Append a ByteString to the last Name of an AnchoredPath.

Unsafe functions.

floatBS :: ByteString -> AnchoredPath Source

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

floatPath :: FilePath -> AnchoredPath Source

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).

replacePrefixPath :: AnchoredPath -> AnchoredPath -> AnchoredPath -> AnchoredPath Source

Take a prefix path, the changed prefix path, and a path to change. Assumes the prefix path is a valid prefix. If prefix is wrong return AnchoredPath [].