Safe Haskell	Safe-Inferred
Language	Haskell2010

Darcs.Util.Tree

Contents

Unfolding stubbed (lazy) Trees.
Tree access and lookup.
Files (Blobs).
Filtering trees.
Manipulating trees.
Properties

Description

The abstract representation of a Tree and useful abstract utilities to handle those.

Synopsis

data Tree m
data Blob m = Blob !(m ByteString) !(Maybe Hash)
data TreeItem m
- = File !(Blob m)
- | SubTree !(Tree m)
- | Stub !(m (Tree m)) !(Maybe Hash)
data ItemType
- = TreeType
- | BlobType
data Hash
makeTree :: [(Name, TreeItem m)] -> Tree m
makeTreeWithHash :: [(Name, TreeItem m)] -> Hash -> Tree m
emptyTree :: Tree m
emptyBlob :: Monad m => Blob m
makeBlob :: Monad m => ByteString -> Blob m
makeBlobBS :: Monad m => ByteString -> Blob m
expandUpdate :: Monad m => (AnchoredPath -> Tree m -> m (Tree m)) -> Tree m -> m (Tree m)
expand :: Monad m => Tree m -> m (Tree m)
expandPath :: Monad m => Tree m -> AnchoredPath -> m (Tree m)
checkExpand :: (TreeItem IO -> IO Hash) -> Tree IO -> IO (Either [(AnchoredPath, Maybe Hash, Maybe Hash)] (Tree IO))
items :: Tree m -> Map Name (TreeItem m)
list :: Tree m -> [(AnchoredPath, TreeItem m)]
listImmediate :: Tree m -> [(Name, TreeItem m)]
treeHash :: Tree m -> Maybe Hash
lookup :: Tree m -> Name -> Maybe (TreeItem m)
find :: Tree m -> AnchoredPath -> Maybe (TreeItem m)
findFile :: Tree m -> AnchoredPath -> Maybe (Blob m)
findTree :: Tree m -> AnchoredPath -> Maybe (Tree m)
itemHash :: TreeItem m -> Maybe Hash
itemType :: TreeItem m -> ItemType
zipCommonFiles :: (AnchoredPath -> Blob m -> Blob m -> a) -> Tree m -> Tree m -> [a]
zipFiles :: (AnchoredPath -> Maybe (Blob m) -> Maybe (Blob m) -> a) -> Tree m -> Tree m -> [a]
zipTrees :: (AnchoredPath -> Maybe (TreeItem m) -> Maybe (TreeItem m) -> a) -> Tree m -> Tree m -> [a]
diffTrees :: forall m. Monad m => Tree m -> Tree m -> m (Tree m, Tree m)
explodePath :: Tree m -> AnchoredPath -> [AnchoredPath]
explodePaths :: Tree IO -> [AnchoredPath] -> [AnchoredPath]
locate :: Monad m => Tree m -> AnchoredPath -> m (Maybe (TreeItem m))
isDir :: TreeItem m -> Bool
treeHas :: Monad m => Tree m -> AnchoredPath -> m Bool
treeHasDir :: Monad m => Tree m -> AnchoredPath -> m Bool
treeHasFile :: Monad m => Tree m -> AnchoredPath -> m Bool
treeHasAnycase :: Monad m => Tree m -> AnchoredPath -> m Bool
readBlob :: Blob m -> m ByteString
class Monad m => FilterTree a m where
- filter :: (AnchoredPath -> TreeItem m -> Bool) -> a m -> a m
restrict :: FilterTree t m => Tree n -> t m -> t m
modifyTree :: Monad m => Tree m -> AnchoredPath -> Maybe (TreeItem m) -> Tree m
updateTree :: Monad m => (TreeItem m -> m (TreeItem m)) -> Tree m -> m (Tree m)
partiallyUpdateTree :: Monad m => (TreeItem m -> m (TreeItem m)) -> (AnchoredPath -> TreeItem m -> Bool) -> Tree m -> m (Tree m)
updateSubtrees :: (Tree m -> Tree m) -> Tree m -> Tree m
overlay :: Applicative m => Tree m -> Tree m -> Tree m
addMissingHashes :: Monad m => (TreeItem m -> m Hash) -> Tree m -> m (Tree m)
prop_explodePath :: Tree m -> AnchoredPath -> Bool

Documentation

data Tree m Source #

Abstraction of a filesystem tree. Please note that the Tree returned by the respective read operations will have TreeStub items in it. To obtain a Tree without such stubs, call expand on it, eg.:

tree <- readDarcsPristine "." >>= expand

When a Tree is expanded, it becomes "final". All stubs are forced and the Tree can be traversed purely. Access to actual file contents stays in IO though.

A Tree may have a Hash associated with it. A pair of Tree's is identical whenever their hashes are (the reverse need not hold, since not all Trees come equipped with a hash).

Instances

Instances details

ApplyMonad Tree DefaultIO Source #
Instance details Defined in Darcs.Repository.ApplyPatches Methods readFilePS :: ObjectIdOf Tree -> DefaultIO ByteString Source #
MonadThrow m => ApplyMonadTrans Tree m Source #
Instance details Defined in Darcs.Patch.ApplyMonad Associated Types type ApplyMonadOver Tree m :: Type -> Type Source # Methods runApplyMonad :: ApplyMonadOver Tree m x -> Tree m -> m (x, Tree m) Source #
Monad m => FilterTree Tree m Source #
Instance details Defined in Darcs.Util.Tree Methods filter :: (AnchoredPath -> TreeItem m -> Bool) -> Tree m -> Tree m Source #
MonadThrow m => ApplyMonad Tree (TreeMonad m) Source #
Instance details Defined in Darcs.Patch.ApplyMonad Methods readFilePS :: ObjectIdOf Tree -> TreeMonad m ByteString Source #
type ApplyMonadOperations Tree Source #
Instance details Defined in Darcs.Patch.ApplyMonad type ApplyMonadOperations Tree = ApplyMonadTree
type ObjectIdOf Tree Source #
Instance details Defined in Darcs.Patch.Object type ObjectIdOf Tree = AnchoredPath
type ApplyMonadOver Tree m Source #
Instance details Defined in Darcs.Patch.ApplyMonad type ApplyMonadOver Tree m = TreeMonad m

data Blob m Source #

Constructors

Blob !(m ByteString) !(Maybe Hash)

data TreeItem m Source #

Constructors

File !(Blob m)
SubTree !(Tree m)
Stub !(m (Tree m)) !(Maybe Hash)

Instances

Instances details

MonadThrow m => ApplyMonad Tree (TreeMonad m) Source #
Instance details Defined in Darcs.Patch.ApplyMonad Methods readFilePS :: ObjectIdOf Tree -> TreeMonad m ByteString Source #
MonadThrow m => ApplyMonadTree (TreeMonad m) Source #
Instance details Defined in Darcs.Patch.ApplyMonad Methods mDoesDirectoryExist :: AnchoredPath -> TreeMonad m Bool Source # mDoesFileExist :: AnchoredPath -> TreeMonad m Bool Source # mReadFilePS :: AnchoredPath -> TreeMonad m ByteString Source # mCreateDirectory :: AnchoredPath -> TreeMonad m () Source # mRemoveDirectory :: AnchoredPath -> TreeMonad m () Source # mCreateFile :: AnchoredPath -> TreeMonad m () Source # mRemoveFile :: AnchoredPath -> TreeMonad m () Source # mRename :: AnchoredPath -> AnchoredPath -> TreeMonad m () Source # mModifyFilePS :: AnchoredPath -> (ByteString -> TreeMonad m ByteString) -> TreeMonad m () Source # mChangePref :: String -> String -> String -> TreeMonad m () Source #

data ItemType Source #

Constructors

TreeType
BlobType

Instances

Instances details

Show ItemType Source #
Instance details Defined in Darcs.Util.Tree Methods showsPrec :: Int -> ItemType -> ShowS # show :: ItemType -> String # showList :: [ItemType] -> ShowS #
Eq ItemType Source #
Instance details Defined in Darcs.Util.Tree Methods (==) :: ItemType -> ItemType -> Bool # (/=) :: ItemType -> ItemType -> Bool #
Ord ItemType Source #
Instance details Defined in Darcs.Util.Tree Methods compare :: ItemType -> ItemType -> Ordering # (<) :: ItemType -> ItemType -> Bool # (<=) :: ItemType -> ItemType -> Bool # (>) :: ItemType -> ItemType -> Bool # (>=) :: ItemType -> ItemType -> Bool # max :: ItemType -> ItemType -> ItemType # min :: ItemType -> ItemType -> ItemType #

data Hash Source #

Instances

Instances details

Read Hash Source #
Instance details Defined in Darcs.Util.Hash Methods readsPrec :: Int -> ReadS Hash # readList :: ReadS [Hash] # readPrec :: ReadPrec Hash # readListPrec :: ReadPrec [Hash] #
Show Hash Source #
Instance details Defined in Darcs.Util.Hash Methods showsPrec :: Int -> Hash -> ShowS # show :: Hash -> String # showList :: [Hash] -> ShowS #
Eq Hash Source #
Instance details Defined in Darcs.Util.Hash Methods (==) :: Hash -> Hash -> Bool # (/=) :: Hash -> Hash -> Bool #
Ord Hash Source #
Instance details Defined in Darcs.Util.Hash Methods compare :: Hash -> Hash -> Ordering # (<) :: Hash -> Hash -> Bool # (<=) :: Hash -> Hash -> Bool # (>) :: Hash -> Hash -> Bool # (>=) :: Hash -> Hash -> Bool # max :: Hash -> Hash -> Hash # min :: Hash -> Hash -> Hash #

makeTree :: [(Name, TreeItem m)] -> Tree m Source #

makeTreeWithHash :: [(Name, TreeItem m)] -> Hash -> Tree m Source #

emptyTree :: Tree m Source #

emptyBlob :: Monad m => Blob m Source #

makeBlob :: Monad m => ByteString -> Blob m Source #

makeBlobBS :: Monad m => ByteString -> Blob m Source #

Unfolding stubbed (lazy) Trees.

By default, Tree obtained by a read function is stubbed: it will contain Stub items that need to be executed in order to access the respective subtrees. expand will produce an unstubbed Tree.

expandUpdate :: Monad m => (AnchoredPath -> Tree m -> m (Tree m)) -> Tree m -> m (Tree m) Source #

expand :: Monad m => Tree m -> m (Tree m) Source #

Expand a stubbed Tree into a one with no stubs in it. You might want to filter the tree before expanding to save IO. This is the basic implementation, which may be overriden by some Tree instances (this is especially true of the Index case).

expandPath :: Monad m => Tree m -> AnchoredPath -> m (Tree m) Source #

Unfold a path in a (stubbed) Tree, such that the leaf node of the path is reachable without crossing any stubs. Moreover, the leaf ought not be a Stub in the resulting Tree. A non-existent path is expanded as far as it can be.

checkExpand :: (TreeItem IO -> IO Hash) -> Tree IO -> IO (Either [(AnchoredPath, Maybe Hash, Maybe Hash)] (Tree IO)) Source #

Check the disk version of a Tree: expands it, and checks each hash. Returns either the expanded tree or a list of AnchoredPaths where there are problems. The first argument is the hashing function used to create the tree.

Tree access and lookup.

items :: Tree m -> Map Name (TreeItem m) Source #

list :: Tree m -> [(AnchoredPath, TreeItem m)] Source #

List all contents of a Tree.

listImmediate :: Tree m -> [(Name, TreeItem m)] Source #

treeHash :: Tree m -> Maybe Hash Source #

Get hash of a Tree. This is guaranteed to uniquely identify the Tree (including any blob content), as far as cryptographic hashes are concerned. Sha256 is recommended.

lookup :: Tree m -> Name -> Maybe (TreeItem m) Source #

Look up a Tree item (an immediate subtree or blob).

find :: Tree m -> AnchoredPath -> Maybe (TreeItem m) Source #

Find a TreeItem by its path. Gives Nothing if the path is invalid.

findFile :: Tree m -> AnchoredPath -> Maybe (Blob m) Source #

Find a Blob by its path. Gives Nothing if the path is invalid, or does not point to a Blob.

findTree :: Tree m -> AnchoredPath -> Maybe (Tree m) Source #

Find a Tree by its path. Gives Nothing if the path is invalid, or does not point to a Tree.

itemHash :: TreeItem m -> Maybe Hash Source #

Get a hash of a TreeItem. May be Nothing.

itemType :: TreeItem m -> ItemType Source #

zipCommonFiles :: (AnchoredPath -> Blob m -> Blob m -> a) -> Tree m -> Tree m -> [a] Source #

For every pair of corresponding blobs from the two supplied trees, evaluate the supplied function and accumulate the results in a list. Hint: to get IO actions through, just use sequence on the resulting list. NB. This won't expand any stubs.

zipFiles :: (AnchoredPath -> Maybe (Blob m) -> Maybe (Blob m) -> a) -> Tree m -> Tree m -> [a] Source #

For each file in each of the two supplied trees, evaluate the supplied function (supplying the corresponding file from the other tree, or Nothing) and accumulate the results in a list. Hint: to get IO actions through, just use sequence on the resulting list. NB. This won't expand any stubs.

zipTrees :: (AnchoredPath -> Maybe (TreeItem m) -> Maybe (TreeItem m) -> a) -> Tree m -> Tree m -> [a] Source #

diffTrees :: forall m. Monad m => Tree m -> Tree m -> m (Tree m, Tree m) Source #

Cautiously extracts differing subtrees from a pair of Trees. It will never do any unneccessary expanding. Tree hashes are used to cut the comparison as high up the Tree branches as possible. The result is a pair of trees that do not share any identical subtrees. They are derived from the first and second parameters respectively and they are always fully expanded. It might be advantageous to feed the result into zipFiles or zipTrees.

explodePath :: Tree m -> AnchoredPath -> [AnchoredPath] Source #

All paths in the tree that that have the given path as prefix.

explodePath t p == Prelude.filter (p `isPrefix`) (map fst (list t))

explodePaths :: Tree IO -> [AnchoredPath] -> [AnchoredPath] Source #

Like explodePath but for multiple paths.

locate :: Monad m => Tree m -> AnchoredPath -> m (Maybe (TreeItem m)) Source #

Like find but monadic and thus able to expand Stubs on the way.

isDir :: TreeItem m -> Bool Source #

treeHas :: Monad m => Tree m -> AnchoredPath -> m Bool Source #

treeHasDir :: Monad m => Tree m -> AnchoredPath -> m Bool Source #

treeHasFile :: Monad m => Tree m -> AnchoredPath -> m Bool Source #

treeHasAnycase :: Monad m => Tree m -> AnchoredPath -> m Bool Source #

Files (Blobs).

readBlob :: Blob m -> m ByteString Source #

Read a Blob into a Lazy ByteString. Might be backed by an mmap, use with care.

Filtering trees.

class Monad m => FilterTree a m where Source #

Methods

filter :: (AnchoredPath -> TreeItem m -> Bool) -> a m -> a m Source #

Given pred tree, produce a Tree that only has items for which pred returns True. The tree might contain stubs. When expanded, these will be subject to filtering as well.

Instances

Instances details

Monad m => FilterTree Tree m Source #
Instance details Defined in Darcs.Util.Tree Methods filter :: (AnchoredPath -> TreeItem m -> Bool) -> Tree m -> Tree m Source #

restrict :: FilterTree t m => Tree n -> t m -> t m Source #

Given two Trees, a guide and a tree, produces a new Tree that is a identical to tree, but only has those items that are present in both tree and guide. The guide Tree may not contain any stubs.

Manipulating trees.

modifyTree :: Monad m => Tree m -> AnchoredPath -> Maybe (TreeItem m) -> Tree m Source #

Modify a Tree (by replacing, or removing or adding items).

updateTree :: Monad m => (TreeItem m -> m (TreeItem m)) -> Tree m -> m (Tree m) Source #

Does not expand the tree.

partiallyUpdateTree :: Monad m => (TreeItem m -> m (TreeItem m)) -> (AnchoredPath -> TreeItem m -> Bool) -> Tree m -> m (Tree m) Source #

Does not expand the tree.

updateSubtrees :: (Tree m -> Tree m) -> Tree m -> Tree m Source #

overlay :: Applicative m => Tree m -> Tree m -> Tree m Source #

Lay one tree over another. The resulting Tree will look like the base (1st parameter) Tree, although any items also present in the overlay Tree will be taken from the overlay. It is not allowed to overlay a different kind of an object, nor it is allowed for the overlay to add new objects to base. This means that the overlay Tree should be a subset of the base Tree (although any extraneous items will be ignored by the implementation).

addMissingHashes :: Monad m => (TreeItem m -> m Hash) -> Tree m -> m (Tree m) Source #

Calculate and insert hashes for all TreeItems contained in a Tree, including the argument Tree itself. If necessary, this expands Stubs.

Properties

prop_explodePath :: Tree m -> AnchoredPath -> Bool Source #

Specification of explodePath