-- Hoogle documentation, generated by Haddock -- See Hoogle, http://www.haskell.org/hoogle/ -- | Pretty BerkeleyDB v4 binding. -- -- This library attempts to provide a memory efficient alternative to -- Data.Map. The BerkeleyDB system is bound and exposed through an -- interface that mimics Data.Map as much as possible. -- -- Features include: pure interface with fairly efficient sharing and a -- very small memory footprint. -- -- Tested with libdb4.6 @package berkeleydb @version 2008.10.31 -- | An efficient implementation of maps from keys to values -- (dictionaries). -- -- Since many function names (but not the type name) clash with -- Prelude names, this module is usually imported -- qualified, e.g. -- --

--   import Data.BerkeleyDB (DB)
--   import qualified Data.BerkeleyDB as DB
--

-- -- The implementation of Db uses the berkeley db library. See -- http://en.wikipedia.org/wiki/Berkeley_DB and -- http://www.oracle.com/technology/products/berkeley-db/index.html -- -- Note that this implementation behaves exactly like a Data.Map.Map -- ByteString ByteString, with the key and value encoded by -- Data.Binary.encode/Data.Binary.decode. This means that keys -- aren't sorted according to Ord. Affected functions are: toList, -- assocs, elems. module Data.BerkeleyDB data Db key value -- | O(log n). Find the value at a key. Calls error when the -- element can not be found. (!) :: (Binary k, Binary v) => Db k v -> k -> v -- | O(1). Is the map empty? null :: Db key value -> Bool -- | O(1). The number of elements in the map. size :: Db key value -> Int -- | O(log n). Is the key a member of the map? member :: (Binary key, Binary value) => key -> Db key value -> Bool -- | O(log n). Is the key not a member of the map? notMember :: (Binary key, Binary value) => key -> Db key value -> Bool -- | O(log n). Lookup the value at a key in the database. -- -- The function will return the result in the monad or -- fail in it the key isn't in the database. Often, the monad to -- use is Maybe, so you get either (Just result) -- or Nothing. lookup :: (Binary key, Binary value, Monad m) => key -> Db key value -> m value -- | O(log n). The expression (findWithDefault def k -- db) returns the value at key k or returns def -- when the key is not in the database. findWithDefault :: (Binary k, Binary a) => a -> k -> Db k a -> a -- | O(1). The empty database. empty :: (Binary key, Binary value) => Db key value -- | O(1). A map with a single element. singleton :: (Binary k, Binary a) => k -> a -> Db k a -- | O(log n). Insert a new key and value in the database. If the -- key is already present in the database, the associated value is -- replaced with the supplied value, i.e. insert is equivalent to -- insertWith const. insert :: (Binary key, Binary value) => key -> value -> Db key value -> Db key value -- | O(log n). Insert with a combining function. -- insertWith f key value db will insert the pair (key, -- value) into db if key does not exist in the database. If the -- key does exist, the function will insert the pair (key, f -- new_value old_value). insertWith :: (Binary k, Binary a) => (a -> a -> a) -> k -> a -> Db k a -> Db k a -- | O(log n). Insert with a combining function. -- insertWithKey f key value db will insert the pair -- (key, value) into db if key does not exist in the database. -- If the key does exist, the function will insert the pair (key,f -- key new_value old_value). Note that the key passed to f is the -- same key passed to insertWithKey. insertWithKey :: (Binary k, Binary a) => (k -> a -> a -> a) -> k -> a -> Db k a -> Db k a -- | O(log n). Delete a key and its value from the database. When -- the key is not a member of the database, the original database is -- returned. delete :: (Binary key, Binary value) => key -> Db key value -> Db key value -- | O(log n). Adjust a value at a specific key. When the key is not -- a member of the map, the original map is returned. adjust :: (Binary k, Binary a) => (a -> a) -> k -> Db k a -> Db k a -- | O(log n). Adjust a value at a specific key. When the key is not -- a member of the map, the original map is returned. adjustWithKey :: (Binary k, Binary a) => (k -> a -> a) -> k -> Db k a -> Db k a -- | O(log n). The expression (update f k map) -- updates the value x at k (if it is in the map). If -- (f x) is Nothing, the element is deleted. If it is -- (Just y), the key k is bound to the new value -- y. update :: (Binary k, Binary a) => (a -> Maybe a) -> k -> Db k a -> Db k a -- | O(log n). The expression (updateWithKey f k db) -- updates the value x at k (if it is in the database). -- If (f k x) is Nothing, the element is deleted. If it -- is (Just y), the key k is bound to the new -- value y. updateWithKey :: (Binary k, Binary a) => (k -> a -> Maybe a) -> k -> Db k a -> Db k a -- | O(log n). The expression (updateWithKey f k db) -- updates the value x at k (if it is in the database). -- If (f k x) is Nothing, the element is deleted. If it -- is (Just y), the key k is bound to the new -- value y. updateLookupWithKey :: (Binary k, Binary a) => (k -> a -> Maybe a) -> k -> Db k a -> (Maybe a, Db k a) -- | O(log n). The expression (alter f k db) alters -- the value x at k, or absence thereof. alter -- can be used to insert, delete, or update a value in a Db. In -- short : lookup k (alter f k m) = f (lookup k -- m) alter :: (Binary k, Binary a) => (Maybe a -> Maybe a) -> k -> Db k a -> Db k a -- | O(log n*m). The expression (union t1 t2) takes -- the left-biased union of t1 and t2. It prefers -- t1 when duplicate keys are encountered, i.e. -- (union == unionWith const). union :: (Binary key, Binary value) => Db key value -> Db key value -> Db key value -- | O(log n*m). Union with a combining function. unionWith :: (Binary key, Binary value) => (value -> value -> value) -> Db key value -> Db key value -> Db key value -- | O(log n*m)). Union with a combining function. This function is -- most efficient on (bigset union smallset). unionWithKey :: (Binary key, Binary value) => (key -> value -> value -> value) -> Db key value -> Db key value -> Db key value -- | The union of a list of databases: (unions == foldl -- union empty). unions :: (Binary k, Binary a) => [Db k a] -> Db k a -- | The union of a list of databases, with a combining operation: -- (unionsWith f == foldl (unionWith f) -- empty). unionsWith :: (Binary k, Binary a) => (a -> a -> a) -> [Db k a] -> Db k a -- | O(n). Map a function over all values in the database. map :: (Binary a, Binary b, Binary k) => (a -> b) -> Db k a -> Db k b -- | O(n). Map a function over all values in the database. mapWithKey :: (Binary a, Binary b, Binary k) => (k -> a -> b) -> Db k a -> Db k b -- | O(n). Fold the values in the map, such that fold f z -- == foldr f z . elems. For example, -- --

--   elems map = fold (:) [] map
--

fold :: (Binary k, Binary a) => (a -> b -> b) -> b -> Db k a -> b -- | O(n). Return all elements of the database in the ascending -- order of their keys sorted by their binary representation. elems :: (Binary key, Binary value) => Db key value -> [value] -- | O(n). Return all keys of the database in ascending order sorted -- by their binary representation. keys :: (Binary key, Binary value) => Db key value -> [key] -- | O(n). Return all key/value pairs in the map in ascending key -- order. assocs :: (Binary key, Binary value) => Db key value -> [(key, value)] -- | O(n). Convert to a list of key/value pairs. toList :: (Binary key, Binary value) => Db key value -> [(key, value)] -- | O(n*log n). Build a database from a list of key/value pairs. -- See also fromAscList. fromList :: (Binary key, Binary value) => [(key, value)] -> Db key value -- | O(n*log n). Build a database from a list of key/value pairs -- with a combining function. fromListWith :: (Binary k, Binary a) => (a -> a -> a) -> [(k, a)] -> Db k a -- | O(n*log n). Build a database from a list of key/value pairs -- with a combining function. fromListWithKey :: (Binary k, Binary a) => (k -> a -> a -> a) -> [(k, a)] -> Db k a -- | O(n). Filter all values that satisfy the predicate. filter :: (Binary k, Binary a) => (a -> Bool) -> Db k a -> Db k a -- | O(n). Filter all keys/values that satisfy the predicate. filterWithKey :: (Binary k, Binary a) => (k -> a -> Bool) -> Db k a -> Db k a instance Typeable2 Db instance Show Range instance (Data k, Data a, Binary k, Binary a) => Data (Db k a) instance (Binary k, Binary a) => Monoid (Db k a) instance (Binary key, Binary value, Ord key, Ord value) => Ord (Db key value) instance (Binary key, Binary value, Eq key, Eq value) => Eq (Db key value) instance (Binary k, Binary a, Read k, Read a) => Read (Db k a) instance (Binary key, Binary value, Show key, Show value) => Show (Db key value) instance (Show key, Show value, Binary key, Binary value) => Binary (Db key value)