Copyright	(C) 2012-2016 Edward Kmett
License	BSD-style (see the file LICENSE)
Maintainer	Edward Kmett <ekmett@gmail.com>
Stability	experimental
Portability	non-portable
Safe Haskell	Safe
Language	Haskell98

Control.Lens.Internal.Level

Contents

Levels

Description

This module provides implementation details of the combinators in Control.Lens.Level, which provides for the breadth-first Traversal of an arbitrary Traversal.

Synopsis

Levels

data Level i a Source

This data type represents a path-compressed copy of one level of a source data structure. We can safely use path-compression because we know the depth of the tree.

Path compression is performed by viewing a Level as a PATRICIA trie of the paths into the structure to leaves at a given depth, similar in many ways to a IntMap, but unlike a regular PATRICIA trie we do not need to store the mask bits merely the depth of the fork.

One invariant of this structure is that underneath a Two node you will not find any Zero nodes, so Zero can only occur at the root.

Constructors

Two !Word !(Level i a) !(Level i a)
One i a
Zero

Instances

TraversableWithIndex i (Level i) Source
Methods itraverse :: Applicative f => (i -> a -> f b) -> Level i a -> f (Level i b) Source itraversed :: (Indexable i p, Applicative f) => p a (f b) -> Level i a -> f (Level i b) Source
FoldableWithIndex i (Level i) Source
Methods ifoldMap :: Monoid m => (i -> a -> m) -> Level i a -> m Source ifolded :: (Indexable i p, Contravariant f, Applicative f) => p a (f a) -> Level i a -> f (Level i a) Source ifoldr :: (i -> a -> b -> b) -> b -> Level i a -> b Source ifoldl :: (i -> b -> a -> b) -> b -> Level i a -> b Source ifoldr' :: (i -> a -> b -> b) -> b -> Level i a -> b Source ifoldl' :: (i -> b -> a -> b) -> b -> Level i a -> b Source
FunctorWithIndex i (Level i) Source
Methods imap :: (i -> a -> b) -> Level i a -> Level i b Source imapped :: (Indexable i p, Settable f) => p a (f b) -> Level i a -> f (Level i b) Source
Functor (Level i) Source
Methods fmap :: (a -> b) -> Level i a -> Level i b (<$) :: a -> Level i b -> Level i a
Foldable (Level i) Source
Methods fold :: Monoid m => Level i m -> m foldMap :: Monoid m => (a -> m) -> Level i a -> m foldr :: (a -> b -> b) -> b -> Level i a -> b foldr' :: (a -> b -> b) -> b -> Level i a -> b foldl :: (b -> a -> b) -> b -> Level i a -> b foldl' :: (b -> a -> b) -> b -> Level i a -> b foldr1 :: (a -> a -> a) -> Level i a -> a foldl1 :: (a -> a -> a) -> Level i a -> a toList :: Level i a -> [a] null :: Level i a -> Bool length :: Level i a -> Int elem :: Eq a => a -> Level i a -> Bool maximum :: Ord a => Level i a -> a minimum :: Ord a => Level i a -> a sum :: Num a => Level i a -> a product :: Num a => Level i a -> a
Traversable (Level i) Source
Methods traverse :: Applicative f => (a -> f b) -> Level i a -> f (Level i b) sequenceA :: Applicative f => Level i (f a) -> f (Level i a) mapM :: Monad m => (a -> m b) -> Level i a -> m (Level i b) sequence :: Monad m => Level i (m a) -> m (Level i a)
(Eq i, Eq a) => Eq (Level i a) Source
Methods (==) :: Level i a -> Level i a -> Bool (/=) :: Level i a -> Level i a -> Bool
(Ord i, Ord a) => Ord (Level i a) Source
Methods compare :: Level i a -> Level i a -> Ordering (<) :: Level i a -> Level i a -> Bool (<=) :: Level i a -> Level i a -> Bool (>) :: Level i a -> Level i a -> Bool (>=) :: Level i a -> Level i a -> Bool max :: Level i a -> Level i a -> Level i a min :: Level i a -> Level i a -> Level i a
(Read i, Read a) => Read (Level i a) Source
Methods readsPrec :: Int -> ReadS (Level i a) readList :: ReadS [Level i a] readPrec :: ReadPrec (Level i a) readListPrec :: ReadPrec [Level i a]
(Show i, Show a) => Show (Level i a) Source
Methods showsPrec :: Int -> Level i a -> ShowS show :: Level i a -> String showList :: [Level i a] -> ShowS

newtype Deepening i a Source

This is an illegal Monoid used to construct a single Level.

Constructors

Deepening
Fields runDeepening :: forall r. Int -> (Level i a -> Bool -> r) -> r

Instances

Monoid (Deepening i a) Source	This is an illegal `Monoid`.
Methods mempty :: Deepening i a mappend :: Deepening i a -> Deepening i a -> Deepening i a mconcat :: [Deepening i a] -> Deepening i a
Semigroup (Deepening i a) Source
Methods (<>) :: Deepening i a -> Deepening i a -> Deepening i a sconcat :: NonEmpty (Deepening i a) -> Deepening i a stimes :: Integral b => b -> Deepening i a -> Deepening i a

deepening :: i -> a -> Deepening i a Source

Generate the leaf of a given Deepening based on whether or not we're at the correct depth.

newtype Flows i b a Source

This is an illegal Applicative used to replace the contents of a list of consecutive Level values representing each layer of a structure into the original shape that they were derived from.

Attempting to Flow something back into a shape other than the one it was taken from will fail.

Constructors

Flows
Fields runFlows :: [Level i b] -> a

Instances

Functor (Flows i b) Source
Methods fmap :: (a -> c) -> Flows i b a -> Flows i b c (<$) :: a -> Flows i b c -> Flows i b a
Applicative (Flows i b) Source	This is an illegal `Applicative`.
Methods pure :: a -> Flows i b a (<>) :: Flows i b (a -> c) -> Flows i b a -> Flows i b c (>) :: Flows i b a -> Flows i b c -> Flows i b c (<*) :: Flows i b a -> Flows i b c -> Flows i b a
Apply (Flows i b) Source
Methods (<.>) :: Flows i b (a -> c) -> Flows i b a -> Flows i b c (.>) :: Flows i b a -> Flows i b c -> Flows i b c (<.) :: Flows i b a -> Flows i b c -> Flows i b a