danimal141

module M1
  class << self
    def included(klass)
      p klass
      klass.extend ClassMethods
    end
  end
  
  def method_i
    p 'InstanceMethodですよー'

danimal141

require 'active_support/concern'

module M1
  # ActiveSupport::Concernをextendしとけばdef included(klass)~とかしなくても勝手にClassMethods取り込んでくれる
  # ActiveSupport::Concernがincludeで呼び出されるappend_featuresを上書きしてるぽい
  extend ActiveSupport::Concern
  
  def method_i
    p 'InstanceMethodですよー'
  end

danimal141

#without memoizing
fibonacci = ->
  if n > 2 then n else fibonacci(n - 2) + fibonacci(n - 1);

for i in [0..10]
  console.log('i = ' + fibonacci(i))

#memoize
fibonacci = do ->
  memo = [0, 1]

danimal141

# without memoizing
def fibonacci n
  n < 2 ? n : fibonacci(n - 2) + fibonacci(n - 1)
end

10.times { |i| p fibonacci(i) }

# memoize
module Fibonacci
  @@memo = [0, 1]

danimal141

class Class
  def define_accessor *args
    args.each do |prop|
      self.class_eval do
        define_method prop do
          return instance_variable_get("@#{prop}")
        end
        
        define_method "#{prop}=" do |val|
          return instance_variable_set("@#{prop}", val)

danimal141

# Before 
def get_file_names path
  file_names = []
  Dir.glob(path).each do |file|
    file_names << File.basename(file) if File::ftype(file) == "file"
  end
  return file_names
end

# After Refactoring

danimal141

require 'active_support/core_ext/module/aliasing'

class A
  def foo
    'foo'
  end
end

class B < A
  def foo_with_bar

danimal141

$!    raise された例外オブジェクト
$"    require で読み込まれたファイルの配列
$#
$$    現在のプロセス ID
$%
$&    正規表現にマッチした箇所の文字列
$'    正規表現にマッチした箇所より後ろの文字列
$(
$)
$*    Ruby スクリプトに指定された引数。ARGV と同じ

danimal141

#include <stdio.h>

int main() {
  int a = 10;
  int *pa = &a;
  int **ppa = &pa;

  printf("%p\n", pa);
  printf("%d\n", *pa);
  printf("%p\n", ppa);

danimal141

def check_sum val
  sum = val.to_s.each_char.with_index.inject([]) do |memo, (char, i)|
    next memo << double_digit_value(char.to_i) if i.odd?
    memo << char.to_i
    memo
  end.inject :+

  if (sum % 10).zero?
    p "#{sum} is divisible by 10. Valid!"
  else