Data.IntTrie

Provides a minimal infinite, lazy trie for integral types. It intentionally leaves out ideas such as delete and emptiness so that it can be used lazily, eg. as the target of an infinite foldr. Essentially its purpose is to be an efficient implementation of a function from integral type, given point-at-a-time modifications.

Documentation

data IntTrie a

A trie from integers to values of type a.

Semantics: [[IntTrie a]] = Integer -> a

Instances

Functor IntTrie

Applicative IntTrie

identity :: Bits a => IntTrie a

The identity trie.

 apply identity = id

apply :: (Ord b, Bits b) => IntTrie a -> b -> a

Apply the trie to an argument. This is the semantic map.

modify :: (Ord b, Bits b) => b -> (a -> a) -> IntTrie a -> IntTrie a

Modify the function at one point

 apply (modify x f t) i | i == x = f (apply t i)
                        | otherwise = apply t i

overwrite :: (Ord b, Bits b) => b -> a -> IntTrie a -> IntTrie a

Overwrite the function at one point

 overwrite i x = modify i (const x)