Copyright | Copyright (c) 2008--2015 wren gayle romano |
---|---|
License | BSD3 |
Maintainer | wren@community.haskell.org |
Stability | provisional |
Portability | portable (with CPP) |
Safe Haskell | None |
Language | Haskell98 |
- data Trie a
- showTrie :: Show a => Trie a -> String
- breakMaximalPrefix :: ByteString -> ByteString -> (ByteString, ByteString, ByteString)
- empty :: Trie a
- null :: Trie a -> Bool
- singleton :: ByteString -> a -> Trie a
- size :: Trie a -> Int
- foldrWithKey :: (ByteString -> a -> b -> b) -> b -> Trie a -> b
- toListBy :: (ByteString -> a -> b) -> Trie a -> [b]
- lookupBy_ :: (Maybe a -> Trie a -> b) -> b -> (Trie a -> b) -> ByteString -> Trie a -> b
- submap :: ByteString -> Trie a -> Trie a
- match_ :: Trie a -> ByteString -> Maybe (Int, a)
- matches_ :: Trie a -> ByteString -> [(Int, a)]
- alterBy :: (ByteString -> a -> Maybe a -> Maybe a) -> ByteString -> a -> Trie a -> Trie a
- alterBy_ :: (ByteString -> a -> Maybe a -> Trie a -> (Maybe a, Trie a)) -> ByteString -> a -> Trie a -> Trie a
- adjustBy :: (ByteString -> a -> a -> a) -> ByteString -> a -> Trie a -> Trie a
- mergeBy :: (a -> a -> Maybe a) -> Trie a -> Trie a -> Trie a
- mapBy :: (ByteString -> a -> Maybe b) -> Trie a -> Trie b
- filterMap :: (a -> Maybe b) -> Trie a -> Trie b
- contextualMap :: (a -> Trie a -> b) -> Trie a -> Trie b
- contextualMap' :: (a -> Trie a -> b) -> Trie a -> Trie b
- contextualFilterMap :: (a -> Trie a -> Maybe b) -> Trie a -> Trie b
- contextualMapBy :: (ByteString -> a -> Trie a -> Maybe b) -> Trie a -> Trie b
- minAssoc :: Trie a -> Maybe (ByteString, a)
- maxAssoc :: Trie a -> Maybe (ByteString, a)
- updateMinViewBy :: (ByteString -> a -> Maybe a) -> Trie a -> Maybe (ByteString, a, Trie a)
- updateMaxViewBy :: (ByteString -> a -> Maybe a) -> Trie a -> Maybe (ByteString, a, Trie a)
Data types
A map from ByteString
s to a
. For all the generic functions,
note that tries are strict in the Maybe
but not in a
.
The Monad
instance is strange. If a key k1
is a prefix of
other keys, then results from binding the value at k1
will
override values from longer keys when they collide. If this is
useful for anything, or if there's a more sensible instance, I'd
be curious to know.
Functions for ByteString
s
breakMaximalPrefix :: ByteString -> ByteString -> (ByteString, ByteString, ByteString) Source
Returns the longest shared prefix and the two remaining suffixes for a pair of strings.
s == (\(pre,s',z') -> pre `append` s') (breakMaximalPrefix s z) z == (\(pre,s',z') -> pre `append` z') (breakMaximalPrefix s z)
Basic functions
singleton :: ByteString -> a -> Trie a Source
O(1), Construct a singleton trie.
Conversion and folding functions
foldrWithKey :: (ByteString -> a -> b -> b) -> b -> Trie a -> b Source
Convert a trie into a list (in key-sorted order) using a function, folding the list as we go.
toListBy :: (ByteString -> a -> b) -> Trie a -> [b] Source
Convert a trie into a list using a function. Resulting values are in key-sorted order.
Query functions
lookupBy_ :: (Maybe a -> Trie a -> b) -> b -> (Trie a -> b) -> ByteString -> Trie a -> b Source
Generic function to find a value (if it exists) and the subtrie rooted at the prefix. The first function argument is called if and only if a node is exactly reachable by the query; if no node is exactly reachable the default value is used; if the middle of an arc is reached, the second function argument is used.
This function is intended for internal use. For the public-facing
version, see lookupBy
in Data.Trie.
submap :: ByteString -> Trie a -> Trie a Source
Return the subtrie containing all keys beginning with a prefix.
match_ :: Trie a -> ByteString -> Maybe (Int, a) Source
Given a query, find the longest prefix with an associated value in the trie, returning the length of that prefix and the associated value.
This function may not have the most useful return type. For a
version that returns the prefix itself as well as the remaining
string, see match
in Data.Trie.
matches_ :: Trie a -> ByteString -> [(Int, a)] Source
Given a query, find all prefixes with associated values in the trie, returning their lengths and values. This function is a good producer for list fusion.
This function may not have the most useful return type. For a
version that returns the prefix itself as well as the remaining
string, see matches
in Data.Trie.
Single-value modification
alterBy :: (ByteString -> a -> Maybe a -> Maybe a) -> ByteString -> a -> Trie a -> Trie a Source
Generic function to alter a trie by one element with a function to resolve conflicts (or non-conflicts).
alterBy_ :: (ByteString -> a -> Maybe a -> Trie a -> (Maybe a, Trie a)) -> ByteString -> a -> Trie a -> Trie a Source
A variant of alterBy
which also allows modifying the sub-trie.
adjustBy :: (ByteString -> a -> a -> a) -> ByteString -> a -> Trie a -> Trie a Source
Alter the value associated with a given key. If the key is not
present, then the trie is returned unaltered. See alterBy
if
you are interested in inserting new keys or deleting old keys.
Because this function does not need to worry about changing the
trie structure, it is somewhat faster than alterBy
.
Combining tries
mergeBy :: (a -> a -> Maybe a) -> Trie a -> Trie a -> Trie a Source
Combine two tries, using a function to resolve collisions. This can only define the space of functions between union and symmetric difference but, with those two, all set operations can be defined (albeit inefficiently).
Mapping functions
filterMap :: (a -> Maybe b) -> Trie a -> Trie b Source
Apply a function to all values, potentially removing them.
contextualMap :: (a -> Trie a -> b) -> Trie a -> Trie b Source
A variant of fmap
which provides access to the subtrie rooted
at each value.
contextualMap' :: (a -> Trie a -> b) -> Trie a -> Trie b Source
A variant of contextualMap
which applies the function strictly.
contextualFilterMap :: (a -> Trie a -> Maybe b) -> Trie a -> Trie b Source
A contextual variant of filterMap
.
contextualMapBy :: (ByteString -> a -> Trie a -> Maybe b) -> Trie a -> Trie b Source
A contextual variant of mapBy
. Again note that this is
expensive since we must reconstruct the keys.
Priority-queue functions
minAssoc :: Trie a -> Maybe (ByteString, a) Source
maxAssoc :: Trie a -> Maybe (ByteString, a) Source
updateMinViewBy :: (ByteString -> a -> Maybe a) -> Trie a -> Maybe (ByteString, a, Trie a) Source
updateMaxViewBy :: (ByteString -> a -> Maybe a) -> Trie a -> Maybe (ByteString, a, Trie a) Source