Add solutions to the Basic data types chapter

Author: BoeingX

src/BasicDatatypes/BasicDatatypes/IntermissionExercises.md

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+# Intermission: Exercises
+
+Given the following datatype
+```haskell
+data Mood = Blah | Woot deriving Show
+```
+
+1. The type constructor is `Mood`.
+
+2. If the function requires a `Mood` value,
+we could use `Blah` and `Woot`.
+
+3. `changeMood :: Mood -> Woot` does not type check because
+`Woot` is a data constructor, not a type constructor.
+
+4. We have
+```haskell
+changeMood Blah = Woot
+changeMood _    = Blah
+```

src/BasicDatatypes/ChapterExercises/Awesome.hs

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+module BasicDatatypes.ChapterExercises.Awesome where
+
+awesome = ["Papuchon", "curry", ":)"]
+alsoAwesome = ["Quake", "The Simons"]
+allAwesome = [awesome, alsoAwesome]
+
+-- Question 1
+-- length :: [a] -> Int
+-- or length :: (Foldable t) => t a -> Int
+
+-- Question 2
+-- length [1, 2, 3, 4, 5] = 5
+-- length [(1, 2), (2, 3), (3, 4)] = 3
+-- length allAwesome = 2
+-- length (concat allAwesome) = 5
+
+-- Question 3
+-- 6 / 3 works
+-- but 6 / length [1, 2, 3] does not type check because
+-- Int has no instance of Fractional
+
+-- Question 4
+-- 6 `div` length [1, 2, 3] 
+
+-- Question 5
+-- 2 + 3 == 5 :: Bool
+
+-- Question 6
+-- let x = 5
+-- x + 3 == 5 :: Bool
+
+-- Question 7
+q71 = length allAwesome == 2
+q72 = length ['1', 'a', '3', 'b']
+q73 = length allAwesome + length awesome
+q74 = (8 == 8) && ('b' < 'a')
+q75 = (8 == 8) && True
+
+-- Question 8
+isPalindrome :: (Eq a) => [a] -> Bool
+isPalindrome x = x == reverse x
+
+-- Question 9
+myAbs :: Integer -> Integer
+myAbs x = if x < 0 then -x else x
+
+-- Question 10
+f :: (a, b) -> (c, d) -> ((b, d), (a, c))
+f ab cd = ((snd ab, snd cd), (fst ab, fst cd))

src/BasicDatatypes/ChapterExercises/MatchTheFunctionNamesToTheirTypes.md

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+# Match the function names to their types
+
+1. c) `Show a => a -> String` is the type of `show`.
+
+2. b) `Eq a => a -> a -> Bool` is the type of `==`.
+
+3. a) `(a, b) -> a` is the type of `fst`.
+
+4. d) `Num a => a -> a -> a` is the type of `(+)`.

src/BasicDatatypes/ChapterExercises/ReadingSyntax.hs

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+module BasicDatatypes.ChapterExercises.ReadingSyntax where
+
+-- Question 1
+x = (+)
+f xs = w `x` 1
+    where w = length xs
+
+-- Question 2
+id' = \ x -> x
+
+-- Question 3
+head' = \ (x : xs) -> x
+
+-- Question 4
+f' (a, b) = a

src/BasicDatatypes/ComparingValues/IntermissionExercises.hs

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+module BasicDatatypes.ComparingValues.IntermissionExercises where
+
+-- Question 1
+a = not True && True
+
+-- Question 2
+b = not (5 == 6)
+
+-- Question 3
+c = (1 * 2) > 5
+
+-- Question 4
+d = "Merry" > "Happy"
+
+-- Question 5
+e = ['1', '2', '3'] ++ "look at me!"