shigemk2

function a() { return "hoge"; }
function b() { eeee eeee } // SyntaxError: Unexpected identifier

(5 <= 6) ? console.log(a()) : console.log(b());
// (5 >= 6) ? console.log(a()) : console.log(b()); // エラー

shigemk2

function a() { return "hoge"; }
function b() { eeee }

(5 <= 6) ? console.log(a()) : console.log(b());
// (5 >= 6) ? console.log(a()) : console.log(b()); // エラー

shigemk2

"use strict"; // この場合はグローバル

function a() {
  "use strict"; // 関数スコープみたいなもの
};

// use strictを二重に書いても問題はない
// 実装者が考えてくれという話
// プログラムは書かれていなくてもいい

shigemk2

"use strict"; // この場合はグローバル

function a() {
  "use strict"; // 関数スコープみたいなもの
};

// use strictを二重に書いても問題はない

shigemk2

import Data.Monoid
import qualified Data.Foldable as F

data Tree a = EmptyTree | Node a (Tree a) (Tree a) deriving (Show)

instance F.Foldable Tree where
    foldMap f EmptyTree = mempty
    foldMap f (Node x l r) = F.foldMap f l `mappend`
                             f x `mappend`
                             F.foldMap f r

shigemk2

import qualified Data.Foldable as F

main = do
    print $ foldr (*) 1 [1,2,3]
    print $ F.foldr (*) 1 [1,2,3]

    print $ F.foldl (+) 2 (Just 9)
    print $ F.foldr (||) False (Just True)

shigemk2

import Data.Monoid

main = do
    print $ Nothing `mappend` Just "andy"
    print $ Just LT `mappend` Nothing
    print $ Just (Sum 3) `mappend` Just (Sum 4)
    print $ getFirst $ First (Just 'a') `mappend` First (Just 'b')
    print $ getFirst $ First Nothing `mappend` First (Just 'b')
    print $ getFirst $ First (Just 'a') `mappend` First Nothing
    print $ getFirst . mconcat . map First $ [Nothing, Just 9, Just 10]

shigemk2

import Data.Monoid

main = do
    print $ Nothing `mappend` Just "andy"
    print $ Just LT `mappend` Nothing
    print $ Just (Sum 3) `mappend` Just (Sum 4)
    print $ getFirst $ First (Just 'a') `mappend` First (Just 'b')
    print $ getFirst $ First Nothing `mappend` First (Just 'b')
    print $ getFirst $ First (Just 'a') `mappend` First Nothing
    print $ getFirst . mconcat . map First $ [Nothing, Just 9, Just 10]

shigemk2

import Data.Monoid

main = do
    print $ Nothing `mappend` Just "andy"
    print $ Just LT `mappend` Nothing
    print $ Just (Sum 3) `mappend` Just (Sum 4)
    print $ getFirst $ First (Just 'a') `mappend` First (Just 'b')
    print $ getFirst $ First Nothing `mappend` First (Just 'b')
    print $ getFirst $ First (Just 'a') `mappend` First Nothing
    print $ getFirst . mconcat . map First $ [Nothing, Just 9, Just 10]

shigemk2

import Data.Monoid

lengthCompare1 :: String -> String -> Ordering
lengthCompare1 x y = let a = length x `compare` length y
                         b = x `compare` y
                    in if a == EQ then b else a

lengthCompare2 :: String -> String -> Ordering
lengthCompare2 x y = (length x `compare` length y) `mappend`
                    (x `compare` y)