Perl, Python - データのあるオブジェクト(セッターとゲッター)

続・初めてのPerl 改訂版
Randal L. Schwartz
brian d foy, Tom Phoenix 著

開発環境

• OS X Lion - Apple(OS)
• BBEdit - Bare Bones Software, Inc., Emacs(Text Editor)
• プログラミング言語: Perl

『続・初めてのPerl 改訂版』(Randal L. Schwartz, brian d foy, Tom Phoenix 著、伊藤 直也、田中 慎司、吉川 英興 監訳、株式会社ロングテール/長尾 高弘 訳、オライリー・ジャパン、2006年、ISBN4-87311-305-9)の12章(データのあるオブジェクト)の12.15(練習問題)1を解いてみる。

その他参考書籍

• プログラミングPerl〈VOLUME1〉
• プログラミングPerl〈VOLUME2〉
• Perlクックブック〈VOLUME1〉
• Perlクックブック〈VOLUME2〉

1.

コード(BBEdit)

sample.pl

#!/usr/bin/env perl
use strict;
use warnings;
use 5.016;
use utf8;
binmode STDOUT, ':utf8';
binmode STDIN, ':utf8';
binmode STDERR, ':utf8';

{ package LivingCreature;
  sub speak {
      my $either = shift;
      if (@_) {
          say "a $either goes '@_'";
      } else {
          say "a $either goes ", $either->sound, "!";
      }
  }
}

{ package Person;
  sub sound { 'hmmmmm' }
  our @ISA = qw(LivingCreature);
}

{ package Animal;
  use Carp qw(croak);
  our @ISA = qw(LivingCreature);
  sub new {
      ref(my $class = shift) and croak "class name needed";
      my $name = shift;
      my $self = {Name => $name, Color => $class->default_color};
      bless $self, $class;
  }
  sub default_color{ 'brown' }
  sub set_name {
      ref(my $self = shift) or croak "instance variable(name) needed";
      $self->{Name} = shift;
  }
  sub name {
      my $either = shift;
      ref $either
          ? $either->{Name}
          : "an unnamed $either";
  }
  sub set_color {
      ref(my $self = shift) or croak "instance variable(color) needed";
      $self->{Color} = shift;
  }
  sub color {
      my $either = shift;
      ref $either
          ? $either->{Color}
          : $either->default_color;
  }
  sub sound {
      croak '動物のsoundが定義されていない！';
  }
  sub speak {
     my $either = shift;
     if (@_) {
         croak "ドリトル博士ではないので、動物と話はできません！" if @_;
     } else {
         $either->SUPER::speak;
     }
 }
}

{ package Cow;
  our @ISA = qw(Animal);
  sub sound { 'moooo' }
}

{ package Horse;
  our @ISA = qw(Animal);
  sub sound { 'neigh' }
}

{ package Sheep;
  our @ISA = qw(Animal);
  sub sound { 'baaaah' }
  sub color{ 'white' }
}

{ package Mouse;
  our @ISA = qw(Animal);
  sub sound { 'squeak' }
  sub speak {
      my $class = shift;
      $class->SUPER::speak;
      say "[but you can barely hear it!]";
  }
}

my $tv_horse = Horse->new('Mr. Ed');
$tv_horse->set_name('Mister Ed');
$tv_horse->set_color('grey');
say $tv_horse->name, ' is ', $tv_horse->color;
say Sheep->name, ' colored ', Sheep->color, ' goes ', Sheep->sound;

入出力結果(Terminal)

$ ./sample.pl
Mister Ed is grey
an unnamed Sheep colored white goes baaaah
$

ちなみにpython3.3の場合。

コード(BBEdit)

sample.py

#!/usr/bin/env python3.3
## Copyright (C) 2013 by kamimura
#-*- coding: utf-8 -*-

import sys

class LivingCreature:
    def speak(self, words=None):
        if words:
            print("a {0} goes '{1}'".format(
                self.__class__.__name__, words))
        else:
            print('a {0} goes {1}!'.format(
                self.__class__.__name__, self.sound()))

class Person(LivingCreature):
    def getSound(self):
        return 'hmmmmm'

class Animal(LivingCreature):
    name = 'an unnamed'
    def __init__(self, name):
        self._name = name
        self._color = 'brown'
    def setName(self, name):
        self._name = name
    def getName(self):
        return self._name
    def setColor(self, color):
        self._color = color
    def getColor(self):
        return self._color
    def getSound(self):
        print('動物のsoundが定義されていない')
        sys.exit()
    def speak(self, words=None):
        if words:
            print('ドリトル博士ではないので、動物と話はできません！')
        else:
            print('a {0} goes {1}!'.format(
                self.__class__.__name__, self.sound()))

class Cow(Animal):
    def getSound(self):
        return 'moooo'

class Horse(Animal):
    def getSound(self):
        return 'neigh'

class Sheep(Animal):
    name = Animal.name + ' Sheep'
    color = 'white'
    sound = 'baaaah'
    def getSound(self):
        return 'baaaah'

class Mouse(Animal):
    def getSound(self):
        return 'squeak'
    def speak(self):
        Animal.speak(self)
        print('[but you can barely hear it!]')

animals = {'Animal':Animal, 'Cow': Cow, 'Horse': Horse, 'Sheep': Sheep,
           'Mouse': Mouse}

tv_horse = Horse('Mr. Ed')
tv_horse.setName('Mister ED')
tv_horse.setColor('grey')
print('{0} is {1}'.format(tv_horse.getName(), tv_horse.getColor()))
print('{0} colored {1} goes {2}'.format(
    Sheep.name, Sheep.color, Sheep.sound))

入出力結果(Terminal)

$ ./sample.py
Mister ED is grey
an unnamed Sheep colored white goes baaaah
$