Assume you have a type like:
data Entry = Entry Author [Author] Updated Id Content newtype Updated = Updated EpochTime newtype Id = Id Int64 newtype Content = Content String newtype Author = Author Email type Email = String
- Decide what parts of your type you want indexed and make your type an instance of Indexable
instance Indexable Entry () where empty = ixSet [ Ix (Map.empty::Map Author (Set Entry)) -- out of order , Ix (Map.empty::Map Id (Set Entry)) , Ix (Map.empty::Map Updated (Set Entry)) , Ix (Map.empty::Map Test (Set Entry)) -- bogus index , Ix (Map.empty::Map Word (Set Entry)) -- text index ] calcs entry = () -- words for text indexing purposes
entries = foldr insert empty [e1,e2,e3,e4]
entries' = foldr delete entries [e1,e3]
entries'' = update e4 e5 entries
- Use the query functions below to grab data from it. e.g.
entries @< (Updated t1) @= (Author "john@doe.com")
will find all items in entries updated earlier than t1
by
john@doe.com
.
- Text Index
If you want to do add a text index extract the words in entry and pass
them in the calc
method of the Indexable
class. Then if you want
all entries with either word1 or word2, you change the instance to
getWords entry = let Just (Content s) = gGet entry in map Word $ words s
instance Indexable Entry [Word] where .... calcs entry = getWords entry
Now you can do this query to find entries with any of the words
entries @+ [Word "word1",Word "word2"]
And if you want all entries with both:
entries @* [Word "word1",Word "word2"]
- Find only the first author
If an Entry has multiple authors and you want to be able to query
on the first author, define a FirstAuthor
datatype and add it to the
result of calc. calc e = (toWords e, getFirstAuthor e)
and now you can
do
newtype FirstAuthor = FirstAuthor Email
getFirstAuthor = let Just (Author a) = gGet Entry in FirstAuthor a
instance Indexable Entry ([Word],FirstAuthor) ... empty = .... Ix (Map.empty::Map FirstAuthor (Set Entry))] calcs entry = (getWords Entry,getFirstAuthor entry) entries @= (FirstAuthor "john@doe.com") -- guess what this does
- module Ix
- data IxSet a
- class Data b => Indexable a b | a -> b where
- noCalcs :: t -> ()
- inferIxSet :: String -> Name -> Name -> [Name] -> Q [Dec]
- ixSet :: [Ix a] -> IxSet a
- type IndexOp = forall k a. (Ord k, Ord a) => k -> a -> Map k (Set a) -> Map k (Set a)
- change :: (Data a, Ord a, Data b, Indexable a b) => IndexOp -> a -> IxSet a -> IxSet a
- insert :: (Data a, Ord a, Data b, Indexable a b) => a -> IxSet a -> IxSet a
- delete :: (Data a, Ord a, Data b, Indexable a b) => a -> IxSet a -> IxSet a
- updateIx :: (Indexable a b, Ord a, Data a, Typeable k) => k -> a -> IxSet a -> IxSet a
- deleteIx :: (Indexable a b, Ord a, Data a, Typeable k) => k -> IxSet a -> IxSet a
- fromSet :: (Indexable a b, Ord a, Data a) => Set a -> IxSet a
- fromList :: (Indexable a b, Ord a, Data a) => [a] -> IxSet a
- toSet :: Ord a => IxSet a -> Set a
- toList :: Ord a => IxSet a -> [a]
- getOne :: Ord a => IxSet a -> Maybe a
- getOneOr :: Ord a => a -> IxSet a -> a
- size :: Ord a => IxSet a -> Int
- null :: IxSet a -> Bool
- (&&&) :: (Ord a, Data a, Indexable a b) => IxSet a -> IxSet a -> IxSet a
- (|||) :: (Ord a, Data a, Indexable a b) => IxSet a -> IxSet a -> IxSet a
- union :: (Ord a, Data a, Indexable a b) => IxSet a -> IxSet a -> IxSet a
- intersection :: (Ord a, Data a, Indexable a b) => IxSet a -> IxSet a -> IxSet a
- (@=) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> k -> IxSet a
- (@<) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> k -> IxSet a
- (@>) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> k -> IxSet a
- (@<=) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> k -> IxSet a
- (@>=) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> k -> IxSet a
- (@><) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> (k, k) -> IxSet a
- (@>=<) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> (k, k) -> IxSet a
- (@><=) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> (k, k) -> IxSet a
- (@>=<=) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> (k, k) -> IxSet a
- (@+) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> [k] -> IxSet a
- (@*) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> [k] -> IxSet a
- getEQ :: (Indexable a b, Data a, Ord a, Typeable k) => k -> IxSet a -> IxSet a
- getLT :: (Indexable a b, Data a, Ord a, Typeable k) => k -> IxSet a -> IxSet a
- getGT :: (Indexable a b, Data a, Ord a, Typeable k) => k -> IxSet a -> IxSet a
- getLTE :: (Indexable a b, Data a, Ord a, Typeable k) => k -> IxSet a -> IxSet a
- getGTE :: (Indexable a b, Data a, Ord a, Typeable k) => k -> IxSet a -> IxSet a
- getRange :: (Indexable a b, Typeable k, Ord a, Data a) => k -> k -> IxSet a -> IxSet a
- groupBy :: (Typeable k, Typeable t) => IxSet t -> [(k, [t])]
- getOrd :: (Indexable a b, Ord a, Data a, Typeable k) => Ordering -> k -> IxSet a -> IxSet a
- stats :: Ord a => IxSet a -> (Int, Int, Int, Int)
Documentation
module Ix
Set type
Typeable1 IxSet | |
(Data ctx a, Sat (ctx (IxSet a)), Sat (ctx [a]), Indexable a b, Data a, Ord a) => Data ctx (IxSet a) | |
(Eq a, Ord a, Typeable a) => Eq (IxSet a) | |
Data a => Data (IxSet a) | |
(Eq a, Ord a, Typeable a) => Ord (IxSet a) | |
(Ord a, Read a, Data a, Indexable a b) => Read (IxSet a) | |
(Ord a, Show a) => Show (IxSet a) | |
(Indexable a b, Data a, Ord a) => Monoid (IxSet a) | |
Version (IxSet a) | |
(Serialize a, Ord a, Data a, Indexable a b) => Serialize (IxSet a) | |
(Indexable a b, Data a, Ord a, Default a) => Default (IxSet a) |
class Data b => Indexable a b | a -> b whereSource
Indexable
class defines objects that can be members of IxSet
.
If you don't want calculated values use
.
Indexable
a ()
inferIxSet :: String -> Name -> Name -> [Name] -> Q [Dec]Source
Template Haskell helper function for automatically building an
Indexable
instance from a data type, e.g.
data Foo = Foo Int String
and
$(inferIxSet "FooDB" ''Foo 'noCalcs [''Int,''String])
will build a type synonym
type FooDB = IxSet Foo
with Int
and String
as indices.
WARNING: The type specified as the first index must be a type which
appears in all values in the IxSet
or toList
and toSet
will
not function properly. You will be warned not to do this by runtime error.
You can always use the element type itself. For example:
$(inferIxSet "FooDB" ''Foo 'noCalcs [''Foo, ''Int, ''String])
Changes to set
delete :: (Data a, Ord a, Data b, Indexable a b) => a -> IxSet a -> IxSet aSource
Removes an item from the IxSet
.
Creation
Conversion
Size checking
Set operations
(&&&) :: (Ord a, Data a, Indexable a b) => IxSet a -> IxSet a -> IxSet aSource
An infix intersection
operation.
(|||) :: (Ord a, Data a, Indexable a b) => IxSet a -> IxSet a -> IxSet aSource
An infix union
operation.
union :: (Ord a, Data a, Indexable a b) => IxSet a -> IxSet a -> IxSet aSource
Takes the union of the two IxSet
s.
intersection :: (Ord a, Data a, Indexable a b) => IxSet a -> IxSet a -> IxSet aSource
Takes the intersection of the two IxSet
s.
Indexing
(@=) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> k -> IxSet aSource
Infix version of getEQ
.
(@<) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> k -> IxSet aSource
Infix version of getLT
.
(@>) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> k -> IxSet aSource
Infix version of getGT
.
(@<=) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> k -> IxSet aSource
Infix version of getLTE
.
(@>=) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> k -> IxSet aSource
Infix version of getGTE
.
(@><) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> (k, k) -> IxSet aSource
Returns the subset with indices in the open interval (k,k).
(@>=<) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> (k, k) -> IxSet aSource
Returns the subset with indices in [k,k).
(@><=) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> (k, k) -> IxSet aSource
Returns the subset with indices in (k,k].
(@>=<=) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> (k, k) -> IxSet aSource
Returns the subset with indices in [k,k].
(@+) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> [k] -> IxSet aSource
Creates the subset that has an index in the provided list.
(@*) :: (Indexable a b, Data a, Ord a, Typeable k) => IxSet a -> [k] -> IxSet aSource
Creates the subset that matches all the provided indices.
getEQ :: (Indexable a b, Data a, Ord a, Typeable k) => k -> IxSet a -> IxSet aSource
Returns the subset with an index equal to the provided key. The set must be indexed over key type, doing otherwise results in runtime error.
getLT :: (Indexable a b, Data a, Ord a, Typeable k) => k -> IxSet a -> IxSet aSource
Returns the subset with an index less than the provided key. The set must be indexed over key type, doing otherwise results in runtime error.
getGT :: (Indexable a b, Data a, Ord a, Typeable k) => k -> IxSet a -> IxSet aSource
Returns the subset with an index greater than the provided key. The set must be indexed over key type, doing otherwise results in runtime error.
getLTE :: (Indexable a b, Data a, Ord a, Typeable k) => k -> IxSet a -> IxSet aSource
Returns the subset with an index less than or equal to the provided key. The set must be indexed over key type, doing otherwise results in runtime error.
getGTE :: (Indexable a b, Data a, Ord a, Typeable k) => k -> IxSet a -> IxSet aSource
Returns the subset with an index greater than or equal to the provided key. The set must be indexed over key type, doing otherwise results in runtime error.
getRange :: (Indexable a b, Typeable k, Ord a, Data a) => k -> k -> IxSet a -> IxSet aSource
Returns the subset with an index within the interval provided. The bottom of the interval is closed and the top is open, i. e. [k1;k2). The set must be indexed over key type, doing otherwise results in runtime error.
groupBy :: (Typeable k, Typeable t) => IxSet t -> [(k, [t])]Source
Returns lists of elements paired with the indices determined by type inference.
getOrd :: (Indexable a b, Ord a, Data a, Typeable k) => Ordering -> k -> IxSet a -> IxSet aSource
A function for building up selectors on IxSet
s. Used in the
various get* functions. The set must be indexed over key type,
doing otherwise results in runtime error.
Debugging and optimisation
stats :: Ord a => IxSet a -> (Int, Int, Int, Int)Source
Statistics about IxSet
. This function returns quadruple
consisting of 1. total number of elements in the set 2. number of
declared indices 3. number of keys in all indices 4. number of
values in all keys in all indices. This can aid you in debugging
and optimisation.