{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# 6-2-3 クラスメソッド"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       ":class_method"
      ]
     },
     "execution_count": 1,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "class Klass\n",
    "  def self.class_method\n",
    "    :class_method\n",
    "  end\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Klass\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       ":class_method"
      ]
     },
     "execution_count": 2,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "class Klass\n",
    "  def (p self).class_method\n",
    "    :class_method\n",
    "  end\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       ":class_method"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "class Klass\n",
    "  def Klass.class_method\n",
    "    :class_method\n",
    "  end\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       ":class_method"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "class Klass\n",
    "end\n",
    "\n",
    "def Klass.class_method\n",
    "  :class_method\n",
    "end\n",
    "\n",
    "Klass.class_method"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### 6-2-4 メソッドの定義"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       ":Klass"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "def Klass\n",
    "  def instance_method\n",
    "    :instance_method\n",
    "  end\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       ":instance_method"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "class Klass\n",
    "  define_method :instance_method, -> {:instance_method}\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       ":instance_method"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "object = Klass.new\n",
    "object.instance_method"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       ":included_module_method"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "module IncludedModule\n",
    "  def included_module_method\n",
    "    :included_module_method\n",
    "  end\n",
    "end\n",
    "\n",
    "class Klass\n",
    "  include IncludedModule\n",
    "\n",
    "  define_method :included_module_method,\n",
    "    IncludedModule.instance_method(:included_module_method)\n",
    "end\n",
    "\n",
    "object = Klass.new\n",
    "object.included_module_method"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       ":un_included_module_method"
      ]
     },
     "execution_count": 15,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "module UnIncludedModule\n",
    "  def un_included_module_method\n",
    "    :un_included_module_method\n",
    "  end\n",
    "end\n",
    "\n",
    "class Klass\n",
    "  define_method :un_included_module_method, UnIncludedModule.instance_method(:un_included_module_method)\n",
    "end\n",
    "# Ruby 1.9 ではエラーになるけれど 2.0 以降は MethodTransplanting のおかげでエラーにはならない。"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Ruby 2.5.1",
   "language": "ruby",
   "name": "ruby"
  },
  "language_info": {
   "file_extension": ".rb",
   "mimetype": "application/x-ruby",
   "name": "ruby",
   "version": "2.5.1"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}