-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Tutorial for the lens library
--   
--   This is a basic tutorial that you can use to get started with the
--   <tt>lens</tt> library. This tutorial covers:
--   
--   <ul>
--   <li>The motivation behind the <tt>lens</tt> library</li>
--   <li>How to use the library for the most common use cases</li>
--   <li>How to interpret type errors</li>
--   <li>Basic familiarity with how lenses work under the hood</li>
--   </ul>
@package lens-tutorial
@version 1.0.5


-- | This <tt>lens</tt> tutorial targets Haskell beginners and assumes only
--   basic familiarity with Haskell. By the end of this tutorial you
--   should:
--   
--   <ul>
--   <li>understand what problems the <tt>lens</tt> library solves,</li>
--   <li>know when it is appropriate to use the <tt>lens</tt> library,</li>
--   <li>be proficient in the most common <tt>lens</tt> idioms,</li>
--   <li>understand the drawbacks of using lenses, and:</li>
--   <li>know where to look if you wish to learn more advanced tricks.</li>
--   </ul>
--   
--   If you would like to follow along with these examples, just import
--   this module:
--   
--   <pre>
--   $ ghci
--   &gt;&gt;&gt; import Control.Lens.Tutorial
--   </pre>
module Control.Lens.Tutorial
data Atom
Atom :: String -> Point -> Atom
[_element] :: Atom -> String
[_point] :: Atom -> Point
element :: Lens' Atom String
point :: Lens' Atom Point
data Point
Point :: Double -> Double -> Point
[_x] :: Point -> Double
[_y] :: Point -> Double
x :: Lens' Point Double
y :: Lens' Point Double
data Molecule
Molecule :: [Atom] -> Molecule
[_atoms] :: Molecule -> [Atom]
atoms :: Iso' Molecule [Atom]
data Pair a
Pair :: a -> a -> Pair a

-- | Map each element of a structure to an action, evaluate these actions
--   from left to right, and collect the results. For a version that
--   ignores the results see <a>traverse_</a>.
--   
--   <h4><b>Examples</b></h4>
--   
--   Basic usage:
--   
--   In the first two examples we show each evaluated action mapping to the
--   output structure.
--   
--   <pre>
--   &gt;&gt;&gt; traverse Just [1,2,3,4]
--   Just [1,2,3,4]
--   </pre>
--   
--   <pre>
--   &gt;&gt;&gt; traverse id [Right 1, Right 2, Right 3, Right 4]
--   Right [1,2,3,4]
--   </pre>
--   
--   In the next examples, we show that <a>Nothing</a> and <a>Left</a>
--   values short circuit the created structure.
--   
--   <pre>
--   &gt;&gt;&gt; traverse (const Nothing) [1,2,3,4]
--   Nothing
--   </pre>
--   
--   <pre>
--   &gt;&gt;&gt; traverse (\x -&gt; if odd x then Just x else Nothing)  [1,2,3,4]
--   Nothing
--   </pre>
--   
--   <pre>
--   &gt;&gt;&gt; traverse id [Right 1, Right 2, Right 3, Right 4, Left 0]
--   Left 0
--   </pre>
traverse :: (Traversable t, Applicative f) => (a -> f b) -> t a -> f (t b)
instance GHC.Show.Show Control.Lens.Tutorial.Point
instance GHC.Show.Show Control.Lens.Tutorial.Atom
instance GHC.Show.Show Control.Lens.Tutorial.Molecule
instance Data.Traversable.Traversable Control.Lens.Tutorial.Pair
instance Data.Foldable.Foldable Control.Lens.Tutorial.Pair
instance GHC.Base.Functor Control.Lens.Tutorial.Pair