happstack-ixset-0.5.0.2: Efficient relational queries on Haskell sets.

Happstack.Data.IxSet.Ix

Description

This module defines typable indices and convenience functions. Should be probably considered private to Happstack.Data.IxSet.

Synopsis

Documentation

data Ix a Source

Ix is a Map from some Typeable key to a set of values for that key. Ix carries type information inside.

Constructors

forall key . (Typeable key, Ord key) => Ix (Map key (Set a)) 

Instances

Typeable1 Ix 
(Data ctx a, Sat (ctx (Ix a))) => Data ctx (Ix a) 
Data a => Data (Ix a) 

insert :: (Ord a, Ord k) => k -> a -> Map k (Set a) -> Map k (Set a)Source

Convenience function for inserting into Maps of Sets as in the case of an Ix. If they key did not already exist in the Map, then a new Set is added transparently.

delete :: (Ord a, Ord k) => k -> a -> Map k (Set a) -> Map k (Set a)Source

Convenience function for deleting from Maps of Sets If the resulting Set is empty, then the entry is removed from the Map.