Data.Conduit.VFS.InMemory

This is intended to demonstrate how a VFS can be defined, but is also entirely usable in code if you find its functionality useful.

This VFS implementation stores its values in a lazy in-memory map, which is itself persisted into an MVar and captured in the monadic state. This requires the monad to be in the class MonadUnliftIO, but that allows the state to be shared throughout the application, maintaining value consistency across threads and even across invocations.

Individual read and write operations are atomic.

The FilePath values used in this VFS are split using splitPath and joined using </>, but are otherwise used directly: there is no concept of paths being "relative" or "absolute" for this VFS. It is also possible for a file and a directory to have the same name, since directories names are appended with /, as per splitPath. (This implementation detail is up for debate and may be changed in a future major release: please file an issue if you want to have a discussion around it.)

Documentation

data InMemoryVFS m a

The basic implementation of the VFS.

Instances

MonadTrans InMemoryVFS

Defined in Data.Conduit.VFS.InMemory

Methods

lift :: Monad m => m a -> InMemoryVFS m a

Monad m => MonadReader InMemoryVFSRoot (InMemoryVFS m)

Defined in Data.Conduit.VFS.InMemory

Methods

ask :: InMemoryVFS m InMemoryVFSRoot

local :: (InMemoryVFSRoot -> InMemoryVFSRoot) -> InMemoryVFS m a -> InMemoryVFS m a

reader :: (InMemoryVFSRoot -> a) -> InMemoryVFS m a

Monad m => Monad (InMemoryVFS m)

Defined in Data.Conduit.VFS.InMemory

Methods

(>>=) :: InMemoryVFS m a -> (a -> InMemoryVFS m b) -> InMemoryVFS m b

(>>) :: InMemoryVFS m a -> InMemoryVFS m b -> InMemoryVFS m b

return :: a -> InMemoryVFS m a

fail :: String -> InMemoryVFS m a

Functor m => Functor (InMemoryVFS m)

Defined in Data.Conduit.VFS.InMemory

Methods

fmap :: (a -> b) -> InMemoryVFS m a -> InMemoryVFS m b

(<$) :: a -> InMemoryVFS m b -> InMemoryVFS m a

MonadFail m => MonadFail (InMemoryVFS m)

Defined in Data.Conduit.VFS.InMemory

Methods

fail :: String -> InMemoryVFS m a

Applicative m => Applicative (InMemoryVFS m)

Defined in Data.Conduit.VFS.InMemory

Methods

pure :: a -> InMemoryVFS m a

(<*>) :: InMemoryVFS m (a -> b) -> InMemoryVFS m a -> InMemoryVFS m b

liftA2 :: (a -> b -> c) -> InMemoryVFS m a -> InMemoryVFS m b -> InMemoryVFS m c

(*>) :: InMemoryVFS m a -> InMemoryVFS m b -> InMemoryVFS m b

(<*) :: InMemoryVFS m a -> InMemoryVFS m b -> InMemoryVFS m a

MonadIO m => MonadIO (InMemoryVFS m)

Defined in Data.Conduit.VFS.InMemory

Methods

liftIO :: IO a -> InMemoryVFS m a

MonadUnliftIO m => VFSC (InMemoryVFS m)

Defined in Data.Conduit.VFS.InMemory

Methods

vfsTouchSink :: ConduitT (VFileType, FilePath) Void (InMemoryVFS m) ()

MonadUnliftIO m => WriteVFSC (InMemoryVFS m)

A class denoting that the type is usable as VFS conduits for writing.

Defined in Data.Conduit.VFS.InMemory

Methods

vfsWriteSink :: ConduitT (FilePath, ByteString) Void (InMemoryVFS m) ()

vfsWriteEitherSink :: ConduitT (Either FilePath ByteString) Void (InMemoryVFS m) ()

vfsRemoveSink :: VFSSink (InMemoryVFS m) ()

MonadUnliftIO m => ReadVFSC (InMemoryVFS m)

Defined in Data.Conduit.VFS.InMemory

Methods

vfsTypeC :: ConduitT FilePath (FilePath, Maybe VFileType) (InMemoryVFS m) ()

vfsContentsC :: ConduitT FilePath (FilePath, ByteString) (InMemoryVFS m) ()

vfsContentsEitherC :: ConduitT FilePath (Either FilePath ByteString) (InMemoryVFS m) ()

vfsChildrenC :: VFSPipe (InMemoryVFS m)

vfsChildFilesC :: VFSPipe (InMemoryVFS m)

vfsChildDirsC :: VFSPipe (InMemoryVFS m)

vfsDescendentsC :: VFSPipe (InMemoryVFS m)

vfsDescFilesC :: VFSPipe (InMemoryVFS m)

vfsDescDirsC :: VFSPipe (InMemoryVFS m)

data InMemoryVFSRoot

The root of the VFS.

Instances

Monad m => MonadReader InMemoryVFSRoot (InMemoryVFS m)

Defined in Data.Conduit.VFS.InMemory

Methods

ask :: InMemoryVFS m InMemoryVFSRoot

local :: (InMemoryVFSRoot -> InMemoryVFSRoot) -> InMemoryVFS m a -> InMemoryVFS m a

reader :: (InMemoryVFSRoot -> a) -> InMemoryVFS m a

runInMemoryVFS :: MonadUnliftIO m => InMemoryVFS m a -> m a

Given an InMemoryVFS, run it in the local monad.

runInMemoryVFS' :: InMemoryVFSRoot -> InMemoryVFS m a -> m a

Runs an InMemoryVFS using a provided InMemoryVFSRoot.

mkInMemoryVFSRoot :: MonadIO m => m InMemoryVFSRoot

Creates an InMemoryVFSRoot that can be shared among many InMemoryVFS invocations.