From 48639513952f32df6c88031218135f638413cab1 Mon Sep 17 00:00:00 2001
From: Dzyuba Vlad <Dzyubavlad@gmail.com>
Date: Tue, 13 Dec 2016 08:59:58 +0200
Subject: [PATCH 1/3] Added first example

---
 Haskell/maybe.hs | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 Haskell/maybe.hs

diff --git a/Haskell/maybe.hs b/Haskell/maybe.hs
new file mode 100644
index 0000000..07a2846
--- /dev/null
+++ b/Haskell/maybe.hs
@@ -0,0 +1,19 @@
+import Prelude hiding (Maybe(..), Functor, fmap, (<$>))
+
+data Maybe a = Just a | Nothing
+  deriving (Show)
+
+class Functor f where
+  fmap  :: (a -> b) -> f a -> f b
+  
+(<$>) :: Functor f => (a -> b) -> f a -> f b
+(<$>) = fmap
+infixl 4 <$>
+
+instance Functor Maybe where
+  fmap f (Just x) = Just $ f x
+  fmap _ Nothing  = Nothing
+
+main = do
+ print $ (* 2) <$> Just 5
+ print $ (* 2) <$> Nothing

From 700e8212c702f88f8f6ca5095165fe92f429d594 Mon Sep 17 00:00:00 2001
From: Dzyuba Vlad <Dzyubavlad@gmail.com>
Date: Tue, 13 Dec 2016 09:10:59 +0200
Subject: [PATCH 2/3] Add second example

---
 Haskell/maybe2.hs | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 Haskell/maybe2.hs

diff --git a/Haskell/maybe2.hs b/Haskell/maybe2.hs
new file mode 100644
index 0000000..803222f
--- /dev/null
+++ b/Haskell/maybe2.hs
@@ -0,0 +1,3 @@
+main = do
+  print $ (* 2) . (+ 5) . (^ 2) <$> Just 5
+  print $ (* 2) . (+ 5) . (^ 2) <$> Nothing

From 493ddfb69893064c262d95ffaf697298c95c2a52 Mon Sep 17 00:00:00 2001
From: Dzyuba Vlad <Dzyubavlad@gmail.com>
Date: Tue, 13 Dec 2016 09:42:13 +0200
Subject: [PATCH 3/3] Add third example

---
 Haskell/maybe3.hs | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 Haskell/maybe3.hs

diff --git a/Haskell/maybe3.hs b/Haskell/maybe3.hs
new file mode 100644
index 0000000..ef94131
--- /dev/null
+++ b/Haskell/maybe3.hs
@@ -0,0 +1,24 @@
+import Prelude hiding (Applicative(..))
+
+class Functor f => Applicative f where
+  pure  :: a -> f a
+  (<*>) :: f (a -> b) -> f a -> f b
+  (*>)  :: f a -> f b -> f b
+  (<*)  :: f a -> f b -> f a
+
+  a *> b = fmap const b <*> a
+  (<*)   = flip (*>)
+  {-# MINIMAL pure, (<*>) #-}
+
+instance Applicative Maybe where
+  pure           = Just
+  (Just f) <*> v = fmap f v
+  Nothing  <*> _ = Nothing
+
+main = do
+  let a = Just 5
+      b = Just $ (* 2) . (+ 5) . (^ 2)
+      c = b <*> a
+  print c
+
+