演習問題３（レジ袋　 Iterator）

演習問題３－３（Iterator）

演習問題３－２では、ShopperList クラスは、Shopper クラス固有のメソッドである getCount() や getAt(int) を使用していました。そのため、Shopper クラスの変更に影響を受ける可能性があります。

そこで、配列などのデータ構造の各要素に対する繰返し処理を抽象化したイテレータを用いて、以下の ShopperList クラスが動作するように書き換えなさい。

以下のように変更した ShopperList クラスの makeInfo メソッドが動作するように変更する
ShopperIterator クラスを作成する
Shopper クラスに、ShopperIterator のインスタンスを返す iterator メソッドを作成する

実行結果

（八百○）大根,125円,1個
（八百○）レタス,294円,2個
（八百○）（△肉店）豚肉,245円,250g
（八百○）（△肉店）鶏肉,156円,200g
（八百○）トマト,276円,4個

コード

Enshu303.java

public class Enshu303 { public static void main(String[] args) { Shopper s1 = new Shopper("八百○", 5); // レジ袋5円 s1.add(new Vegetable("大根", 125, 1)); s1.add(new Vegetable("レタス", 147, 2)); Shopper s2 = new Shopper("△肉店", 3); // レジ袋3円 s2.add(new Meat("豚肉", 98, 250)); s2.add(new Meat("鶏肉", 78, 200)); s1.add(s2); s1.add(new Vegetable("トマト", 69, 4)); System.out.println(s1.getInfo(new ShopperList())); } }

ShopperList.java

public class ShopperList implements IVisitor { // 途中略 public String makeInfo(Shopper shopper) { String saveShop = currentShop; StringBuilder s = new StringBuilder(); currentShop += "（" + shopper.getName() + "）"; ShopperIterator it = shopper.iterator(); while(it.hasNext()) { s.append(it.next().getInfo(this)); } currentShop = saveShop; return s.toString(); } }

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.java

public class ShopperIterator implements Iterator<Goods> { private Shopper shopper; private int index = 0; public ShopperIterator() {} public ShopperIterator(Shopper shopper) { this.shopper = shopper; } public boolean hasNext() { } public Goods next() { } }

本当に見ますか？

ShopperIterator.java

Shopper.java

public class Shopper extends Goods { private ArrayList<Goods> list = new ArrayList<Goods>(); public Shopper(String name, int price) { super(name, price); // レジ袋の店名、レジ袋代 } public int getPrice() { int sum = this.price; // レジ袋代 for(int i = 0 ; i < list.size() ; i++) { sum += ((Goods)list.get(i)).getPrice(); } return sum; } public void add(Goods goods) { list.add(goods); } public Goods getAt(int index) { return (Goods)list.get(index); } public int getCount() { return list.size(); } public String getInfo(IVisitor v) { return v.makeInfo(this); } public ShopperIterator iterator() { return new ShopperIterator(this); } }

ShopperList.java

public class ShopperList implements IVisitor { private String currentShop = ""; public String makeInfo(Vegetable vegetable) { return currentShop + vegetable.getName() + "," + Currency.displayComma(vegetable.getPrice()) + "," + vegetable.getQuantity() + "個\n"; } public String makeInfo(Meat meat) { return currentShop + meat.getName() + "," + Currency.displayComma(meat.getPrice()) + "," + meat.getVolume() + "\n"; } public String makeInfo(Shopper shopper) { String saveShop = currentShop; StringBuilder s = new StringBuilder(); currentShop += "（" + shopper.getName() + "）"; ShopperIterator it = shopper.iterator(); while(it.hasNext()) { s.append(it.next().getInfo(this)); } currentShop = saveShop; return s.toString(); } }

Enshu303.cpp

#include <iostream> using namespace std; #include "Shopper.h" #include "Vegetable.h" #include "Meat.h" #include "Currency.h" int main() { Shopper* s1 = new Shopper("八百○", 5); // レジ袋5円 s1->add(new Vegetable("大根", 125, 1)); s1->add(new Vegetable("レタス", 147, 2)); Shopper* s2 = new Shopper("△肉店", 3); // レジ袋3円 s2->add(new Meat("豚肉", 98, 250)); s2->add(new Meat("鶏肉", 78, 200)); s1->add(s2); s1->add(new Vegetable("トマト", 69, 4)); ShopperList* s = new ShopperList(); cout << s1->getInfo(s) << endl; delete s; delete s1; }

ShopperList.h

#pragma once #include "Visitor.h" class Vegetable; class Meat; class Shopper; class ShopperList : public Visitor { private: std::string currentShop; public: ShopperList(void); virtual ~ShopperList(void); virtual std::string makeInfo(Vegetable* const) = 0; virtual std::string makeInfo(Meat* const) = 0; virtual std::string makeInfo(Shopper* const) = 0; };

ShopperList.cpp

#include "ShopperList.h" #include "Vegetable.h" #include "Meat.h" #include "Shopper.h" #include "Currency.h" using namespace std; // 途中略 string ShopperList::makeInfo(Shopper* shopper) { string saveShop = currentShop; string s = ""; currentShop += "（" + shopper->getName() + "）"; ShopperIterator* it = shopper->iterator(); while (it->hasNext()) { s += it->next()->getInfo(this); } currentShop = saveShop; return s; }

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.h

#pragma once #include "Goods.h" class Shopper; class ShopperIterator { private: Goods* pos; Shopper* shopper; unsigned int index = 0; public: ShopperIterator(Shopper*); virtual ~ShopperIterator(void); bool hasNext(void); Goods* next(void); };

ShopperIterator.cpp

#include "Shopper.h" #include "ShopperIterator.h" ShopperIterator::ShopperIterator(Shopper* shopper) { pos = shopper->getAt(0); this->shopper = shopper; } ShopperIterator::~ShopperIterator(void) {} bool ShopperIterator::hasNext(void) { } Goods* ShopperIterator::next(void) { }

本当に見ますか？

ShopperIterator.h

ShopperIterator.cpp

Shopper.h

#pragma once #include <vector> #include <string> #include "Goods.h" class Shopper : public Goods { private: std::vector<Goods*> list; public: Shopper(void); Shopper(std::string, int); virtual ~Shopper(void); int getPrice(void); void add(Goods*); Goods* getAt(int); int getCount(void); std::string getInfo(Visitor* const); ShopperIterator* iterator(); };

Shopper.cpp

#include "Shopper.h" using namespace std; Shopper::Shopper(void) {} Shopper::Shopper(string n, int p) : Goods(n, p) {} Shopper::~Shopper(void) { vector<Goods*>::iterator it = list.begin(); while (it != list.end()) delete *it++; } int Shopper::getPrice(void) { int sum = price; // レジ袋代 vector<Goods*>::iterator it = list.begin(); while(it != list.end()) sum += (*it++)->getPrice(); return sum; } void Shopper::add(Goods* g) { list.push_back(g); } goods* shopper::getAt(int index) { return list.at(index); } int shopper::getCount(void) { return list.size(); } string shopper::getInfo(Visitor* const v) { return v->makeInfo(this); } ShopperIterator* Shopper::iterator() { return new ShopperIterator(this); }

ShopperList.h

#pragma once #include "Visitor.h" class Vegetable; class Meat; class Shopper; class ShopperList : public Visitor { private: std::string currentShop; public: ShopperList(void); virtual ~ShopperList(void); std::string makeInfo(Vegetable* const); std::string makeInfo(Meat* const); std::string makeInfo(Shopper* const); };

ShopperList.cpp

#include "ShopperList.h" #include "Vegetable.h" #include "Meat.h" #include "Shopper.h" #include "Currency.h" using namespace std; ShopperList::ShopperList(void) { currentShop = ""; } ShopperList::~ShopperList(void) {} string ShopperList::makeInfo(Vegetable* v) { return currentShop + v->getName() + "," + Currency::displayComma(v->getPrice()) + "," + v->getQuantity() + '\n'; } string ShopperList::makeInfo(Meat* m) { return currentShop + m->getName() + "," + Currency::displayComma(m->getPrice()) + "," + m->getVolume() + '\n'; } string ShopperList::makeInfo(Shopper* shopper) { string saveShop = currentShop; string s = ""; currentShop += "（" + shopper->getName() + "）"; ShopperIterator* it = shopper->iterator(); while (it->hasNext()) s += it->next()->getInfo(this); currentShop = saveShop; return s; }

Enshu303.cs

class Program { static void Main(string[] args) { Shopper s1 = new Shopper("八百○", 5); // レジ袋5円 s1.add(new Vegetable("大根", 125, 1)); s1.add(new Vegetable("レタス", 147, 2)); Shopper s2 = new Shopper("△肉店", 3); // レジ袋3円 s2.add(new Meat("豚肉", 98, 250)); s2.add(new Meat("鶏肉", 78, 200)); s1.add(s2); s1.add(new Vegetable("トマト", 69, 4)); Console.WriteLine(s1.getInfo(new ShopperList())); } }

ShopperList.cs

public class ShopperList : IVisitor { // 途中略 public String makeInfo(Shopper shopper) { String saveShop = currentShop; String s = ""; currentShop += "（" + shopper.getName() + "）"; ShopperIterator it = shopper.iterator(); while(it.hasNext()) { s += it.next().getInfo(this); } currentShop = saveShop; return s; } }

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.cs

public class ShopperIterator { private Shopper shopper; private int index; public ShopperIterator(Shopper shopper) { this.shopper = shopper; index = 0; } public bool hasNext() { } public Goods next() { } }

本当に見ますか？

ShopperIterator.cs

Shopper.cs

public class Shopper : Goods { private ArrayList list = new ArrayList(); public Shopper(string name, int price) : base(name, price) { } public override int getPrice() { int sum = price; // レジ袋代 for (int i = 0 ; i < list.Count ; i++) sum += ((Goods)list[i]).getPrice(); return sum; } public void add(Goods goods) { list.Add(goods); } public Goods getAt(int index) { return (Goods)list[index]; } public int getCount() { return list.Count; } public override string getInfo(IVisitor v) { return v.makeInfo(this); } public ShopperIterator iterator() { return new ShopperIterator(this); } }

ShopperList.cs

public class ShopperList : IVisitor { private string currentShop = ""; public string makeInfo(Meat meat) { return currentShop + meat.getName() + "," + Currency.displayComma(meat.getPrice()) + "," + meat.getVolume() + "\n"; } public string makeInfo(Vegetable vegetable) { return currentShop + vegetable.getName() + "," + Currency.displayComma(vegetable.getPrice()) + "," + vegetable.getQuantity() + "個\n"; } public string makeInfo(Shopper shopper) { string saveShop = currentShop; StringBuilder s = new StringBuilder(); currentShop += "（" + shopper.getName() + "）"; ShopperIterator it = shopper.iterator(); while(it.hasNext()) { s.Append(it.next().getInfo(this)); } currentShop = saveShop; return s.ToString(); } }

Enshu303.vb

Module Enshu303 Sub Main() Dim s1 As Shopper = New Shopper("八百○", 5) ' レジ袋5円 s1.add(New Vegetable("大根", 125, 1)) s1.add(New Vegetable("レタス", 147, 2)) Dim s2 As Shopper = New Shopper("△肉店", 3) ' レジ袋3円 s2.add(New Meat("豚肉", 98, 250)) s2.add(New Meat("鶏肉", 78, 200)) s1.add(s2) s1.add(New Vegetable("トマト", 69, 4)) Console.WriteLine(s1.getInfo(New ShopperList())) End Sub End Module

ShopperList.vb

public class ShopperList : IVisitor { ' 途中略 Public Overloads Function makeInfo(shopper As Shopper) As String Implements IVisitor.makeInfo Dim saveShop As String = currentShop Dim s As String = "" currentShop &= "（" & shopper.getName() & "）" Dim it As ShopperIterator = shopper.itarator() While (it.hasNext()) Dim goods As Goods = it.next() s += goods.getInfo(Me) End While currentShop = saveShop Return s End Function End Class

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.vb

Public Class ShopperIterator Protected shopper As Shopper Protected index As Integer = 0 Public Sub New(ByVal shopper As Shopper) Me.shopper = shopper Me.index = 0 End Sub Public Function hasNext() As Boolean End Function Public Function [next]() As Goods End Function End Class

本当に見ますか？

ShopperIterator.vb

Public Class ShopperIterator Protected shopper As Shopper Protected index As Integer = 0 Public Sub New(ByVal shopper As Shopper) Me.shopper = shopper Me.index = 0 End Sub Public Function hasNext() As Boolean Return index < shopper.getCount() End Function Public Function [next]() As Goods index += 1 Return shopper.getAt(index - 1) End Function End Class

Shopper.vb

Public Class Shopper : Inherits Goods Private list As ArrayList = New ArrayList() Public Sub New(name As String, price As Integer) MyBase.New(name, price) End Sub Public Overrides Function getPrice() As Integer Dim sum As Integer = price ' レジ袋代 For i As Integer = 0 To list.Count - 1 sum += DirectCast(list.Item(i), Goods).getPrice() Next Return sum End Function Public Sub add(food As Food) list.Add(food) End Sub Public Function getAt(index As Integer) As Goods Return list(index) End Function Public Function getCount() As Integer Return list.Count End Function Public Overrides Function getInfo(v As IVisitor) As String Return v.makeInfo(Me) End Function Public Function itarator() As ShopperIterator Return New ShopperIterator(Me) End Function End Class

ShopperList.vb

Public Class ShopperList : Implements IVisitor { Private currentShop As String = "" Public Overloads Function makeInfo(vegetable As Vegetable) As String Implements IVisitor.makeInfo Return currentShop & vegetable.getName() & "," & Currency.displayComma(vegetable.getPrice()) & "," & vegetable.getQuantity() & "個" & ControlChars.CrLf End Function Public Overloads Function makeInfo(meat As Meat) As String Implements IVisitor.makeInfo Return currentShop & meat.getName() & "," & Currency.displayComma(meat.getPrice()) & "," & meat.getVolume() & ControlChars.CrLf End Function Public Overloads Function makeInfo(shopper As Shopper) As String Implements IVisitor.makeInfo Dim saveShop As String = currentShop Dim s As StringBuilder = New StringBuilder() currentShop &= "（" & shopper.getName() & "）" Dim it As ShopperIterator = shopper.itarator() While (it.hasNext()) s.Append(it.next().getInfo(Me)) End While currentShop = saveShop Return s.ToString() End Function End Class

Enshu303.js

const Shopper = require("./Shopper.js"); const Vegetable = require("./Vegetable.js"); const Meat = require("./Meat.js"); const ShopperList = require("./ShopperList.js"); let s1 = new Shopper("八百○", 5); // レジ袋5円 s1.add(new Vegetable("大根", 125, 1)); s1.add(new Vegetable("レタス", 147, 2)); let s2 = new Shopper("△肉店", 3); // レジ袋3円 s2.add(new Meat("豚肉", 98, 250)); s2.add(new Meat("鶏肉", 78, 200)); s1.add(s2); s1.add(new Vegetable("トマト", 69, 4)); process.stdout.write(s1.getInfo(new ShopperList()) + "\n");

ShopperList.js

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.js

module.exports = class ShopperIterator { constructor(shopper) { this.shopper = shopper; this.index = 0; } hasNext() { } next() { } }

本当に見ますか？

ShopperIterator.js

module.exports = class ShopperIterator { constructor(shopper) { this.shopper = shopper; this.index = 0; } hasNext() { return (this.index < this.shopper.getCount()); } next() { return this.shopper.getAt(this.index++); } }

Shopper.js

ShopperList.js

Enshu303.pl

use lib './'; use Vegetable; use Meat; use Shopper; use ShopperList; my $s1 = new Shopper("八百○", 5); # レジ袋5円 $s1->add(new Vegetable("大根", 125, 1)); $s1->add(new Vegetable("レタス", 147, 2)); my $s2 = new Shopper("△肉店", 3); # レジ袋3円 $s2->add(new Meat("豚肉", 98, 250)); $s2->add(new Meat("鶏肉", 78, 200)); $s1->add($s2); $s1->add(new Vegetable("トマト", 69, 4)); print $s1->getInfo(new ShopperList()) . "\n";

ShopperList.pm

use Currency; package ShopperList { use base qw(IVisitor); # 途中略 sub makeInfo { my ($this, $goods) = @_; my $ref = ref $goods; if ($ref eq "Vegetable") { # 途中略 elsif ($ref eq "Shopper") { my $saveShop = $this->{currentShop}; my $s = ""; $this->{currentShop} .= "（" . $goods->getName() . "）"; my $it = $goods->iterator(); while ($it->hasNext()) { $s .= $it->next()->getInfo($this); } $this->{currentShop} = $saveShop; return $s; } } } 1;

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.pm

package ShopperIterator { sub new { my ($class, $shopper) = @_; my $this = { shopper => $shopper, index => 0 }; return bless $this, $class; } sub hasNext { } sub next { } } 1;

本当に見ますか？

ShopperIterator.pm

package ShopperIterator { sub new { my ($class, $shopper) = @_; my $this = { shopper => $shopper, index => 0 }; return bless $this, $class; } sub hasNext { my ($this) = @_; return ($this->{index} < $this->{shopper}->getCount()); } sub next { my ($this) = @_; return $this->{shopper}->getAt($this->{index}++); } } 1;

Shopper.pm

package Shopper { use base qw(Goods); sub new { my ($class, $name, $price) = @_; my $this = $class->SUPER::new($name, $price); $this->{list} = (); return bless $this, $class; } sub getPrice { my ($this) = @_; my $sum = $this->{price}; # レジ袋代 foreach my $goods (@{$this->{list}}) { $sum += $goods->getPrice(); } return $sum; } sub add { my ($this, $goods) = @_; push @{$this->{list}}, $goods; } sub getAt { my ($this, $index) = @_; return @{$this->{list}}[$index]; } sub getCount { my ($this) = @_; return @{$this->{list}}; } sub getInfo { my ($this, $v) = @_; return $v->makeInfo($this); } sub iterator() { my ($this) = @_; return new ShopperIterator($this); } } 1;

ShopperList.pm

use Currency; package ShopperList { use base qw(IVisitor); sub new { my ($class) = @_; my $this = { currentShop => "" }; return bless $this, $class; } sub makeInfo { my ($this, $goods) = @_; my $ref = ref $goods; if ($ref eq "Vegetable") { return $this->{currentShop} . $goods->getName() . "," . Currency->displayComma($goods->getPrice()) . "," . $goods->getQuantity() . "個\n"; } elsif ($ref eq "Meat") { return $this->{currentShop} . $goods->getName() . "," . Currency->displayComma($goods->getPrice()) . "," . $goods->getVolume() . "\n"; } elsif ($ref eq "Shopper") { my $saveShop = $this->{currentShop}; my $s = ""; $this->{currentShop} .= "（" . $goods->getName() . "）"; my $it = $goods->iterator(); while ($it->hasNext()) { $s .= $it->next()->getInfo($this); } $this->{currentShop} = $saveShop; return $s; } } } 1;

Enshu302.rb

require './Shopper' require './Vegetable' require './Meat' require './ShopperList' s1 = Shopper.new("八百○", 5) # レジ袋5円 s1.add(Vegetable.new("大根", 125, 1)) s1.add(Vegetable.new("レタス", 147, 2)) s2 = Shopper.new("△肉店", 3) # レジ袋3円 s2.add(Meat.new("豚肉", 98, 250)) s2.add(Meat.new("鶏肉", 78, 200)) s1.add(s2) s1.add(Vegetable.new("トマト", 69, 4)) puts s1.getInfo(ShopperList.new())

ShopperList.rb

require './IVisitor' require './Vegetable' require './Meat' require './Shopper' require './Currency' class ShopperList < IVisitor # 途中略 def makeInfo(goods) if goods.instance_of?(Vegetable) # 途中略 elsif goods.instance_of?(Shopper) saveShop = @currentShop s = "" @currentShop += "（#{goods.getName()}）" it = goods.iterator(); while (it.hasNext()) s += it.next().getInfo(self); end @currentShop = saveShop return s; end end

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.rb

class ShopperIterator def initialize(shopper) @shopper = shopper; @index = 0; end def hasNext() end def next() end end

本当に見ますか？

ShopperIterator.rb

class ShopperIterator def initialize(shopper) @shopper = shopper; @index = 0; end def hasNext() return (@index < @shopper.getCount()); end def next() i = @index; @index += 1; return @shopper.getAt(i); end end

Shopper.rb

require './Goods' class Shopper < Goods def initialize(name, price) @name = name # レジ袋の店名 @price = price # レジ袋代 @list = [] end def getPrice() sum = @price # レジ袋代 for goods in @list sum += goods.getPrice() end return sum end def add(goods) @list.push(goods) end def getAt(index) return @list[index] end def getCount() return @list.length end def getInfo(v) return v.makeInfo(self) end def iterator() return ShopperIterator.new(self); end end

ShopperList.rb

require './IVisitor' require './Vegetable' require './Meat' require './Shopper' require './Currency' class ShopperList < IVisitor def initialize() @currentShop = "" end def makeInfo(goods) if goods.instance_of?(Vegetable) return "#{@currentShop}#{goods.getName()}, " + "#{Currency.displayComma(goods.getPrice())}, " + "#{goods.getQuantity()}個\n" elsif goods.instance_of?(Meat) return "#{@currentShop}#{goods.getName()}, " + "#{Currency.displayComma(goods.getPrice())}, " + "#{goods.getVolume()}\n" elsif goods.instance_of?(Shopper) saveShop = @currentShop s = "" @currentShop += "（#{goods.getName()}）" it = goods.iterator(); while (it.hasNext()) s += it.next().getInfo(self); end @currentShop = saveShop return s; end end

Enshu303.py

from Shopper import Shopper from Vegetable import Vegetable from Meat import Meat from Currency import Currency s1 = Shopper("八百○", 5) # レジ袋5円 s1.add(Vegetable("大根", 125, 1)) s1.add(Vegetable("レタス", 147, 2)) s2 = Shopper("△肉店", 3) # レジ袋3円 s2.add(Meat("豚肉", 98, 250)) s2.add(Meat("鶏肉", 78, 200)) s1.add(s2) s1.add(Vegetable("トマト", 69, 4)) print(s1.getInfo(ShopperList()));

ShopperList.py

from IVisitor import IVisitor from Vegetable import Vegetable from Meat import Meat from Shopper import Shopper from Currency import Currency class ShopperList(IVisitor): # 途中略 def makeInfo(self, goods): if (isinstance(goods, Vegetable)): # 途中略 elif (isinstance(goods, Shopper)): saveShop = self.currentShop; s = ""; self.currentShop += "（" + goods.getName() + "）"; it = goods.iterator(); while (it.hasNext()): s += it.next().getInfo(self); self.currentShop = saveShop; return s;

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.py

class ShopperIterator: def __init__(self, shopper): self.shopper = shopper; self.index = 0; def hasNext(self): def next(self):

本当に見ますか？

ShopperIterator.py

class ShopperIterator: def __init__(self, shopper): self.shopper = shopper; self.index = 0; def hasNext(self): return (self.index < self.shopper.getCount()); def next(self): i = self.index; self.index += 1; return self.shopper.getAt(i);

Shopper.py

from Goods import Goods class Shopper(Goods): def __init__(self, name, price): super().__init__(name, price) self.list = [] def getPrice(self): sum = self.price # レジ袋代 for goods in self.list: sum += goods.getPrice() return sum def add(self, goods): self.list.append(goods) def getAt(self, index): return self.list[index]; def getCount(self): return len(self.list); def getInfo(self, v): return v.makeInfo(self); def iterator(self): return ShopperIterator(self);

ShopperList.py

from IVisitor import IVisitor from Vegetable import Vegetable from Meat import Meat from Shopper import Shopper from Currency import Currency class ShopperList(IVisitor): def __init__(self): self.currentShop = "" def makeInfo(self, goods): if (isinstance(goods, Vegetable)): return self.currentShop + goods.getName() + "," \ + Currency.displayComma(goods.getPrice()) + "," \ + str(goods.getQuantity()) + "個\n"; elif (isinstance(goods, Meat)): return self.currentShop + goods.getName() + "," \ + Currency.displayComma(goods.getPrice()) + "," \ + goods.getVolume() + "\n"; elif (isinstance(goods, Shopper)): saveShop = self.currentShop; s = ""; self.currentShop += "（" + goods.getName() + "）"; it = goods.iterator(); while (it.hasNext()): s += it.next().getInfo(self); self.currentShop = saveShop; return s;

Enshu303.php

<?php require_once('Shopper.php'); require_once('Vegetable.php'); require_once('Meat.php'); require_once('ShopperList.php'); $s1 = new Shopper("八百○", 5); // レジ袋5円 $s1->add(new Vegetable("大根", 125, 1)); $s1->add(new Vegetable("レタス", 147, 2)); $s2 = new Shopper("△肉店", 3); // レジ袋3円 $s2->add(new Meat("豚肉", 98, 250)); $s2->add(new Meat("鶏肉", 78, 200)); $s1->add($s2); $s1->add(new Vegetable("トマト", 69, 4)); print $s1->getInfo(new ShopperList()) . "\n"; ?>

ShopperList.php

<?php require_once('IVisitor.php'); require_once('Currency.php'); require_once('Vegetable.php'); require_once('Shopper.php'); class ShopperList implements IVisitor { // 途中略 public function makeInfo($goods) { if ($goods instanceof Vegetable) { // 途中略 } else if ($goods instanceof Shopper) { $saveShop = $this->currentShop; $s = ""; $this->currentShop .= "（" . $goods->getName() . "）"; $it = $goods->iterator(); while ($it->hasNext()) { $s .= $it->next()->getInfo($this); } $this->currentShop = $saveShop; return $s; } } } ?>

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.php

本当に見ますか？

ShopperIterator.php

<?php class ShopperIterator { private $shopper; private $index; public function __construct($shopper) { $this->shopper = $shopper; $this->index = 0; } public function hasNext() { return ($this->index < $this->shopper->getCount()); } public function next() { return $this->shopper->getAt($this->index++); } } ?>

Shopper.php

<?php require_once('Goods.php'); require_once('ShopperIterator.php'); class Shopper extends Goods { private $list = array(); public function __construct($name, $price) { parent::__construct($name, $price); // レジ袋の店名、レジ袋代 } public function getPrice() { $sum = $this->price; // レジ袋代 foreach($this->$list as $goods) { $sum += $goods->getPrice(); } return $sum; } public function add($goods) { $this->list[] = $goods; } public function getAt($index) { return $this->list[$index]; } public function getCount() { return count($this->list); } public function getInfo($v) { return $v->makeInfo($this); } public function iterator() { return new ShopperIterator($this); } } ?>

ShopperList.php

<?php require_once('IVisitor.php'); require_once('Currency.php'); require_once('Vegetable.php'); require_once('Shopper.php'); class ShopperList implements IVisitor { private $currentShop = ""; public function makeInfo($goods) { if ($goods instanceof Vegetable) { return $this->currentShop . $goods->getName() . "," . Currency::displayComma($goods->getPrice()) . "," . $goods->getQuantity() . "個\n"; } else if ($goods instanceof Meat) { return $this->currentShop . $goods->getName() . "," . Currency::displayComma($goods->getPrice()) . "," . $goods->getVolume() . "\n"; } else if ($goods instanceof Shopper) { $saveShop = $this->currentShop; $s = ""; $this->currentShop .= "（" . $goods->getName() . "）"; $it = $goods->iterator(); while ($it->hasNext()) { $s .= $it->next()->getInfo($this); } $this->currentShop = $saveShop; return $s; } } } ?>

Enshu303.ts

import {Shopper} from "./Shopper"; import {Vegetable} from "./Vegetable"; import {Meat} from "./Meat"; import {ShopperList} from "./ShopperList"; let s1:Shopper = new Shopper("八百○", 5); // レジ袋5円 s1.add(new Vegetable("大根", 125, 1)); s1.add(new Vegetable("レタス", 147, 2)); let s2:Shopper = new Shopper("△肉店", 3); // レジ袋3円 s2.add(new Meat("豚肉", 98, 250)); s2.add(new Meat("鶏肉", 78, 200)); s1.add(s2); s1.add(new Vegetable("トマト", 69, 4)); process.stdout.write(s1.getInfo(new ShopperList()));

ShopperList.ts

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.ts

import { Shopper } from "./Shopper"; import { Goods } from "./Goods"; export class ShopperIterator { private shopper:Shopper; private index:number = 0; public constructor(shopper:Shopper) { this.shopper = shopper; } public hasNext():boolean { } public next():Goods { } }

本当に見ますか？

ShopperIterator.ts

Shopper.ts

import {Goods} from "./Goods"; import {IVisitor} from "./IVisitor"; import {ShopperIterator} from "./ShopperIterator"; export class Shopper extends Goods { private list:Array<Goods> = new Array<Goods>; public constructor(name:string, price:number) { super(name, price); // レジ袋の店名、レジ袋代 } public getPrice():number { let sum:number = this.price; // レジ袋代 this.list.forEach(function(goods) { sum += goods.getPrice(); }); return sum; } public add(goods:Goods):void { this.list.add(goods); } public getAt(index:number):Goods { return this.list[index]; } public getCount():number { return this.list.length; } public getInfo(v:IVisitor):string { return v.makeInfo(this); } public iterator():ShopperIterator { return new ShopperIterator(this); } }

ShopperList.ts

import {IVisitor} from "./IVisitor"; import {Goods} from "./Goods"; import {Vegetable} from "./Vegetable"; import {Meat} from "./Meat"; import {Shopper} from "./Shopper"; import {Currency} from "./Currency"; export class ShopperList implements IVisitor { private currentShop:string = ""; public makeInfo(goods:Goods):string { if (goods instanceof Vegetable) { return this.currentShop + goods.getName() + "," + Currency.displayComma(goods.getPrice()) + "," + goods.getQuantity() + "個\n"; } else if (goods instanceof Meat) { return this.currentShop + goods.getName() + "," + Currency.displayComma(goods.getPrice()) + "," + goods.getVolume() + "\n"; } else if (goods instanceof Shopper) { let saveShop:string = currentShop; let s:string = ""; this.currentShop += "（" + goods.getName() + "）"; let it:ShopperIterator = goods.iterator(); while (it.hasNext()) { s += it.next().getInfo(this); } this.currentShop = saveShop; return s; } } }

Enshu303.swift

let s1:Shopper = Shopper("八百○", 5) // レジ袋5円 s1.add(Vegetable("大根", 125, 1)) s1.add(Vegetable("レタス", 147, 2)) let s2:Shopper = Shopper("△肉店", 3) // レジ袋3円 s2.add(Meat("豚肉", 98, 250)) s2.add(Meat("鶏肉", 78, 200)) s1.add(s2) s1.add(Vegetable("トマト", 69, 4)) print(s1.getInfo(ShopperList()))

ShopperList.swift

public class ShopperList : IVisitor { // 途中略 public func makeInfo(_ shopper:Shopper) -> String { let saveShop:String = currentShop var s:String = "" currentShop += "（" + shopper.getName() + "）" let it:ShopperIterator = shopper.iterator() while(it.hasNext()) { s += it.next().getInfo(self) } currentShop = saveShop return s } }

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.swift

public class ShopperIterator { private var shopper:Shopper private var index:Int = 0 public init(_ shopper:Shopper) { self.shopper = shopper } public func hasNext() -> Bool { } public func next() -> Goods { } }

本当に見ますか？

ShopperIterator.swift

public class ShopperIterator { private var shopper:Shopper private var index:Int = 0 public init(_ shopper:Shopper) { self.shopper = shopper } public func hasNext() -> Bool { return index < this.shopper.getCount() } public func next() -> Goods { let n:Int = index index += 1 return shopper.getAt(n) } }

Shopper.swift

public class Shopper : Goods { private var list:[Goods] = [] public override init(_ name:String, _ price:Int) { super.init(name, price) // レジ袋の店名、レジ袋代 } public override func getPrice() -> Int { var sum:Int = self.price // レジ袋代 list.forEach { sum += $0.getPrice() } return sum } public func add(_ goods:Goods) { list.append(goods) } public func getAt(_ index:Int) -> Goods { return list[index] } public func getCount() -> Int { return list.count } public override func getInfo(_ v:IVisitor) -> String { return v.makeInfo(self) } public func iterator() -> ShopperIterator { return ShopperIterator(self) } }

ShopperList.swift

public class ShopperList : IVisitor { private var currentShop:String = "" public func makeInfo(_ vegetable:Vegetable) -> String { return currentShop + vegetable.getName() + "," + Currency.displayComma(vegetable.getPrice()) + "," + String(vegetable.getQuantity()) + "個\n" } public func makeInfo(_ meat:Meat) -> String { return this.currentShop + meat.getName() + "," + Currency.displayComma(meat.getPrice()) + "," + meat.getVolume() + "\n" } public func makeInfo(_ shopper:Shopper) -> String { let saveShop:String = currentShop let s:String = "" currentShop += "（" + shopper.getName() + "）" let it:ShopperIterator = shopper.iterator() while (it.hasNext()) { s += it.next().getInfo(self) } currentShop = saveShop return s } } }

Enshu303.kt

fun main() { val s1 = Shopper("八百○", 5) // レジ袋5円 s1.add(Vegetable("大根", 125, 1)) s1.add(Vegetable("レタス", 147, 2)) val s2 = Shopper("△肉店", 3) // レジ袋3円 s2.add(Meat("豚肉", 98, 250)) s2.add(Meat("鶏肉", 78, 200)) s1.add(s2) s1.add(Vegetable("トマト", 69, 4)) println(s1.getInfo(ShopperList())) }

ShopperList.kt

internal class ShopperList : IVisitor { // 途中略 override fun makeInfo(shopper: Shopper) : String { val saveShop: String = currentShop var s: String = "" currentShop += "（${goods.getName()}）" val it: ShopperIterator = shopper.iterator() while (it.hasNext()) { s += it.next().getInfo(this) } currentShop = saveShop return s } }

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.kt

class ShopperIterator(shopper: Shopper) { private var index: Int = 0 fun hasNext(): Boolean = fun next(): Goods = }

本当に見ますか？

ShopperIterator.kt

class ShopperIterator(shopper: Shopper) { private var index: Int = 0 fun hasNext(): Boolean = index < shopper.getCount() fun next(): Goods = shopper.getAt(index++) }

Shopper.kt

class Shopper(name: String, price: Int) : Goods(name, price) { private val list = ArrayList<Goods>() override fun getPrice(): Int { var sum: Int = price // レジ袋代 for (goods: Goods in list) { sum += goods.getPrice() } return sum } fun add(goods: Goods) { list.add(goods) } fun getAt(index: Int) : Goods = list[index] fun getCount(): Int = list.size override fun getInfo(v: IVisitor) : String = v.makeInfo(this) operator fun iterator(): ShopperIterator = ShopperIterator(this) }

ShopperList.kt

internal class ShopperList : IVisitor { private var currentShop: String = "" override fun makeInfo(vegetable: Vegetable) : String { return "$currentShop${vegetable.getName()},${Currency.displayComma(vegetable.getPrice())},${vegetable.quantity}個\n" } override fun makeInfo(meat: Meat) : String { return "$currentShop${meat.getName()},${Currency.displayComma(meat.getPrice())},${meat.getVolume()}\n" } override fun makeInfo(shopper: Shopper) : String { val saveShop: String = currentShop var s: String = "" currentShop += "（${goods.getName()}）" val it: ShopperIterator = shopper.iterator() while (it.hasNext()) { s += it.next().getInfo(this) } currentShop = saveShop return s } }

Enshu303.scala

object Main303 { def main(args: Array[String]) { val s1 = Shopper("八百○", 5) // レジ袋5円 s1.add(Vegetable("大根", 125, 1)) s1.add(Vegetable("レタス", 147, 2)) val s2 = Shopper("△肉店", 3) // レジ袋3円 s2.add(Meat("豚肉", 98, 250)) s2.add(Meat("鶏肉", 78, 200)) s1.add(s2) s1.add(Vegetable("トマト", 69, 4)) println(s1.getInfo(ShopperList())) } }

ShopperList.scala

class ShopperList extends IVisitor { // 途中略 def makeInfo(shopper: Shopper) : String = { val saveShop: String = currentShop var s: String = "" currentShop += "（" + shopper.getName() + "）" val it: ShopperIterator = shopper.iterator() while (it.hasNext()) { s += it.next().getInfo(this) } currentShop = saveShop return s } }

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.scala

class ShopperIterator(shopper: Shopper) extends Iterator[Goods] { private var index: Int = 0 def hasNext(): Boolean = def next(): Goods = }

本当に見ますか？

ShopperIterator.scala

class ShopperIterator(shopper: Shopper) extends Iterator[Goods] { private var index: Int = 0 def hasNext(): Boolean = index < shopper.getCount() def next(): Goods = shopper.getAt({index += 1; index - 1}) } }

Shopper.scala

import scala.collection.mutable.ListBuffer class Shopper(name: String, price: Int) extends Goods(name, price) { private val list = new ListBuffer[Goods]() override def getPrice(): Int = { var sum: Int = price // レジ袋代 for (goods: Goods <- list) { sum += goods.getPrice() } sum } def add(goods: Goods) { list.addOne(goods) } def getAt(index: Int) : Goods = list(index) def getCount(): Int = list.size def getInfo(v: IVisitor) : String = v.makeInfo(this) def iterator() = new ShopperIterator(this) }

ShopperList.scala

class ShopperList extends IVisitor { private var currentShop: String = "" def makeInfo(vegetable: Vegetable) : String = currentShop + vegetable.getName() + "," + Currency.displayComma(vegetable.getPrice()) + "," + vegetable.getQuantity() + "個\n" def makeInfo(meat: Meat): String = currentShop + meat.getName() + "," + Currency.displayComma(meat.getPrice()) + "," + meat.getVolume() + "\n" def makeInfo(shopper: Shopper) : String = { val saveShop: String = currentShop var s: String = "" currentShop += "（" + shopper.getName() + "）" val it: ShopperIterator = shopper.iterator() while (it.hasNext()) { s += it.next().getInfo(this) } currentShop = saveShop s } }

Enshu303.groovy

class Enshu303 { static void main(String[] args) { Shopper s1 = new Shopper("八百○", 5) // レジ袋5円 s1.add(new Vegetable("大根", 125, 1)) s1.add(new Vegetable("レタス", 147, 2)) Shopper s2 = new Shopper("△肉店", 3) // レジ袋3円 s2.add(new Meat("豚肉", 98, 250)) s2.add(new Meat("鶏肉", 78, 200)) s1.add(s2) s1.add(new Vegetable("トマト", 69, 4)) System.out.println(s1.getInfo(new ShopperList())) } }

ShopperList.groovy

class ShopperList implements IVisitor { // 途中略 String makeInfo(Shopper shopper) { String saveShop = currentShop StringBuilder s = new StringBuilder() currentShop += "（" + shopper.name + "）" ShopperIterator it = shopper.iterator() while(it.hasNext()) { s.append(it.next().getInfo(this)) } currentShop = saveShop return s.toString() } }

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.groovy

public class ShopperIterator implements Iterator<Goods> { private Shopper shopper private int index = 0 ShopperIterator() {} ShopperIterator(Shopper shopper) { this.shopper = shopper } boolean hasNext() { } Goods next() { } }

本当に見ますか？

ShopperIterator.groovy

Shopper.groovy

public class Shopper extends Goods { private ArrayList<Goods> list = new ArrayList<Goods>() Shopper(String name, int price) { super(name, price) // レジ袋の店名、レジ袋代 } int getPrice() { int sum = this.price; // レジ袋代 for(Goods goods in list) { sum += goods.price } return sum } void add(Goods goods) { list.add(goods) } Goods getAt(int index) { return (Goods)list.get(index) } int getCount() { return list.size() } String getInfo(IVisitor v) { return v.makeInfo(this) } ShopperIterator iterator() { return new ShopperIterator(this) } }

ShopperList.groovy

class ShopperList implements IVisitor { private String currentShop = "" String makeInfo(Vegetable vegetable) { return currentShop + vegetable.name + "," + Currency.displayComma(vegetable.price) + "," + vegetable.quantity + "個\n" } String makeInfo(Meat meat) { return currentShop + meat.name + "," + Currency.displayComma(meat.price) + "," + meat.volume + "\n" } String makeInfo(Shopper shopper) { String saveShop = currentShop StringBuilder s = new StringBuilder() currentShop += "（" + shopper.name + "）" ShopperIterator it = shopper.iterator() while(it.hasNext()) { s.append(it.next().getInfo(this)) } currentShop = saveShop return s.toString() } }

Enshu303.go

import "fmt" func main() { var s1 = NewShopper("八百○", 5) // レジ袋5円 s1.Add(NewVegetable("大根", 125, 1)) s1.Add(NewVegetable("レタス", 147, 2)) var s2 = NewShopper("△肉店", 3) // レジ袋3円 s2.Add(NewMeat("豚肉", 98, 250)) s2.Add(NewMeat("鶏肉", 78, 200)) s1.Add(s2) s1.Add(NewVegetable("トマト", 69, 4)) fmt.Println(s1.GetInfo(NewShopperList())) }

ShopperList.go

import "strconv" type ShopperList struct { IVisitor currentShop string } // 途中略 func (self *ShopperList) makeInfoShopper(shopper *Shopper) string { var saveShop = self.currentShop var s = "" self.currentShop += " (" + shopper.GetName() + ") " var it = shopper.Iterator() for it.HasNext() { s += it.Next().GetInfo(self) } self.currentShop = saveShop return s } func NewShopperList() *ShopperList { return &ShopperList{} }

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

HasNext メソッド: 次の要素があれば true、なければ false を返す
Next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.go

type ShopperIterator struct { shopper *Shopper index int } func (self *ShopperIterator) HasNext() bool { } func (self *ShopperIterator) Next() IGoods { } func NewShopperIterator(shopper *Shopper) *ShopperIterator { return &ShopperIterator{ shopper: shopper, } }

本当に見ますか？

ShopperIterator.go

type ShopperIterator struct { shopper *Shopper index int } func (self *ShopperIterator) HasNext() bool { return self.index < self.shopper.GetCount() } func (self *ShopperIterator) Next() IGoods { var goods = self.shopper.GetAt(self.index) self.index += 1 return goods } func NewShopperIterator(shopper *Shopper) *ShopperIterator { return &ShopperIterator{ shopper: shopper, } }

Shopper.go

type IShopper interface { IGoods Add(goods IGoods) GetName() string GetPrice() int } type Shopper struct { *Goods list []IGoods } func (self *Shopper) GetPrice() { var sum = self.price // レジ袋代 for _, goods := range self.list { sum += goods.GetPrice() } return sum } func (self *Shopper) Add(goods IGoods) { self.list = append(self.list, goods) } func (self *Shopper) GetAt(index int) IGoods { return self.list[index] } func (self *Shopper) GetCount() int { return len(self.list) } func (self *Shopper) GetInfo(v IVisitor) string { return v.makeInfoShopper(self) } func (self *Shopper) Iterator() *ShopperIterator { return NewShopperIterator(self) } func NewShopper(name string, price int) { var s IShopper s = &Shopper { Goods: NewGoods(name, price), // レジ袋の店名、レジ袋代 } self.currentShop = saveShop return s }

ShopperList.go

import "strconv" type ShopperList struct { IVisitor currentShop string } func (self *ShopperList) makeInfoVegetable(vegetable *Vegetable) string { return self.currentShop + vegetable.GetName() + "," + GetCurrency().DisplayComma(vegetable.GetPrice()) + "," + strconv.Itoa(vegetable.GetQuantity()) + "個\n" } func (self *ShopperList) makeInfoMeat(meat *Meat) string { return self.currentShop + meat.GetName() + "," + GetCurrency().DisplayComma(meat.GetPrice()) + "," + meat.GetVolume() + "\n" } func (self *ShopperList) makeInfoShopper(shopper *Shopper) string { var saveShop = self.currentShop var s = "" self.currentShop += " (" + shopper.GetName() + ") " var it = shopper.Iterator() for it.HasNext() { s += it.Next().GetInfo(self) } self.currentShop = saveShop return s } func NewShopperList() *ShopperList { return &ShopperList{} }

enshu303.d

import shopper; import vegetable; import meat; import shopperlist; int main() { Shopper s1 = new Shopper("八百○", 5); // レジ袋5円 s1.add(new Vegetable("大根", 125, 1)); s1.add(new Vegetable("レタス", 147, 2)); Shopper s2 = new Shopper("△肉店", 3); // レジ袋3円 s2.add(new Meat("豚肉", 98, 250)); s2.add(new Meat("鶏肉", 78, 200)); s1.add(s2); s1.add(new Vegetable("トマト", 69, 4)); printfln(s1.getInfo(new ShopperList())); return 0; } private void printfln(T...)(T args) { // Shift JIS 出力 import std, std.windows.charset, core.vararg; std.stdio.writeln(to!(string)(toMBSz(std.format.format(args)))); }

shopperlist.d

import std.format; import ivisitor; import vegetable; import meat; import shopper; import currency; public class ShopperList : IVisitor { // 途中略 public string makeInfo(Shopper shopper) { string saveShop = currentShop; string s = ""; currentShop ~= "（" ~ shopper.getName() ~ "）"; import shopperiterator; ShopperIterator it = shopper.iterator(); while(it.hasNext()) { s ~= it.next().getInfo(this); } currentShop = saveShop; return s; } }

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

shopperiterator.d

import shopper; import goods; public class ShopperIterator { private Shopper shopper; private int index = 0; public this(Shopper shopper) { this.shopper = shopper; } public bool hasNext() { } public Goods next() { } }

本当に見ますか？

shopperiterator.d

shopper.d

import goods; public class Shopper : Goods { private Goods[] list; public this(in string name, in int price) { super(name, price); // レジ袋の店名、レジ袋代 } public override int getPrice() { int sum = this.price; // レジ袋代 foreach (int i; 0..list.length) { sum += (cast(Goods)list[i]).getPrice(); } return sum; } public void add(Goods goods) { list ~= goods; } public Goods getAt(in int index) { return (Goods)list[index]; } public int getCount() { return list.length; } import ivisitor; public override string getInfo(IVisitor v) { return v.makeInfo(this); } import shopperiterator; public ShopperIterator iterator() { return new ShopperIterator(this); } }

shopperlist.d

import std.format; import ivisitor; import vegetable; import meat; import shopper; import currency; public class ShopperList : IVisitor { private string currentShop = ""; public string makeInfo(Vegetable vegetable) { return format("%s%s,%s,%d個\n", currentShop, vegetable.getName(), Currency.displayComma(vegetable.getPrice()), vegetable.getQuantity()); } public string makeInfo(Meat meat) { return format("%s%s,%s,%s\n", currentShop, meat.getName(), Currency.displayComma(meat.getPrice()), meat.getVolume()); } public string makeInfo(Shopper shopper) { string saveShop = currentShop; string s = ""; currentShop ~= "（" ~ shopper.getName() ~ "）"; import shopperiterator; ShopperIterator it = shopper.iterator(); while(it.hasNext()) { s ~= it.next().getInfo(this)); } currentShop = saveShop; return s; } }

Enshu303.dpr

program Enshu303; uses System.SysUtils, UnitShopper, UnitShopperList, UnitVegetable, UnitMeat, UnitCurrency; var s1, s2:Shopper; begin s1 := Shopper.Create('八百○', 5); // レジ袋5円 s1.add(Vegetable.Create('大根', 125, 1)); s1.add(Vegetable.Create('レタス', 147, 2)); s2 := Shopper.Create('△肉店', 3); // レジ袋3円 s2.add(Meat.Create('豚肉', 98, 250)); s2.add(Meat.Create('鶏肉', 78, 200)); s1.add(s2); s1.add(Vegetable.Create('トマト', 69, 4)); Writeln(s1.getInfo(ShopperList.Create())); s1.Free; end.

ShopperList.pas

unit UnitShopperList; interface uses System.SysUtils, UnitIVisitor, UnitVegetable, UnitMeat, UnitShopper, UnitShopperIterator, UnitCurrency; // 途中略 function ShopperList.makeInfo(_goods:TObject):string; var saveShop:string; var i:integer; var s:string; var _vegetable:Vegetable; var _meat:Meat; var _shopper:Shopper; var it:ShopperIterator; begin // 途中略 else if _goods is Shopper then begin _shopper := _goods as Shopper; saveShop := currentShop; currentShop := currentShop + '（' + _shopper.getName() + '）'; s := ''; it := _shopper.iterator() as ShopperIterator; while it.hasNext() do begin s := s + it.next().getInfo(self); end; currentShop := saveShop; Result := s; end; end; end.

ShopperIterator クラスは、以下の2つのメソッドを実装して作成します。

hasNext メソッド: 次の要素があれば true、なければ false を返す
next メソッド　　: 次の要素を返し、その次に進む

ShopperIterator クラスのコード（一部）を見ますか？

ShopperIterator.pas

unit UnitShopperIterator; interface uses UnitIIterator, UnitShopper, UnitGoods; type ShopperIterator = class(TInterfacedObject, IIterator<Goods>) private var _shopper:Shopper; var index:integer; public constructor Create(_shopper:Shopper); function hasNext():boolean; function next:Goods; end; implementation constructor ShopperIterator.Create(_shopper:Shopper); begin self._shopper := _shopper; index := 0; end; function ShopperIterator.hasNext():boolean; begin end; function ShopperIterator.next:Goods; begin end; end.

IIterator クラスのコードを見ますか？

IIterator.pas

unit UnitIIterator; interface type IIterator<T> = interface function hasNext():boolean; function next:T; end; implementation end.

本当に見ますか？

IIterator.pas

unit UnitIIterator; interface type IIterator<T> = interface function hasNext():boolean; function next:T; end; implementation end.

ShopperIterator.pas

unit UnitShopperIterator; interface uses UnitIIterator, UnitShopper, UnitGoods; type ShopperIterator = class(TInterfacedObject, IIterator<Goods>) private var _shopper:Shopper; var index:integer; public constructor Create(_shopper:Shopper); function hasNext():boolean; function next:Goods; end; implementation constructor ShopperIterator.Create(_shopper:Shopper); begin self._shopper := _shopper; index := 0; end; function ShopperIterator.hasNext():boolean; begin Result := index < _shopper.GetCount(); end; function ShopperIterator.next:Goods; begin Result := _shopper.getAt(index); INC(index); end; end.

Shopper.pas

unit UnitShopper; interface uses System.Generics.Collections, UnitIIterator, UnitIVisitor, UnitGoods; type Shopper = class(Goods) private list:TList<Goods>; _iterator:IIterator<Goods>; public constructor Create(name:string; price:integer); destructor Destroy(); override; function getPrice():integer; override; procedure add(_goods:Goods); function getAt(index:integer):Goods; function getCount():integer; function getInfo(v:IVisitor):string; override; function iterator():IIterator<Goods>; end; implementation uses UnitShopperIterator; // 循環参照の回避 constructor Shopper.Create(name:string; price:integer); begin inherited Create(name, price); // レジ袋の店名、レジ袋代 list := TList<Goods>.Create(); end; destructor Shopper.Destroy(); var g:Goods; begin for g in list do begin g.Free; end; list.Free; end; function Shopper.getPrice():integer; var sum:integer; var g:Goods; begin sum := price; // レジ袋代 for g in list do begin sum := sum + g.getPrice(); end; Result := sum; end; procedure Shopper.add(_goods:Goods); begin list.add(_goods); end; function Shopper.getAt(index:integer):Goods; begin Result := list[index]; end; function Shopper.getCount():integer; begin Result := list.Count end; function Shopper.getInfo(v:IVisitor):string; begin Result := v.makeInfo(self); end; function Shopper.iterator():IIterator<Goods>; begin _iterator := ShopperIterator.Create(self); Result := _iterator; end; end.

ShopperList.pas

unit UnitShopperList; interface uses System.SysUtils, UnitIVisitor, UnitVegetable, UnitMeat, UnitShopper, UnitShopperIterator, UnitCurrency; type ShopperList = class(TInterfacedObject, IVisitor) private const CRLF = #13#10; var currentShop:string; public constructor Create(); function makeInfo(_goods:TObject):string; overload; // 循環参照の回避 end; implementation constructor ShopperList.Create(); begin currentShop := ''; end; function ShopperList.makeInfo(_goods:TObject):string; var saveShop:string; var i:integer; var s:string; var _vegetable:Vegetable; var _meat:Meat; var _shopper:Shopper; var it:ShopperIterator; begin if _goods is Vegetable then begin _vegetable := _goods as Vegetable; Result := Format('%s%s, %s, %d個', [currentShop, _vegetable.getName(), Currency.displayComma(_vegetable.getPrice()), _vegetable.getQuantity()]) + CRLF; end else if _goods is Meat then begin _meat := _goods as Meat; Result := Format('%s%s, %s, %s', [currentShop, _meat.getName(), Currency.displayComma(_meat.getPrice()), _meat.getVolume()]) + CRLF; end else if _goods is Shopper then begin _shopper := _goods as Shopper; saveShop := currentShop; currentShop := currentShop + '（' + _shopper.getName() + '）'; s := ''; it := _shopper.iterator() as ShopperIterator; while it.hasNext() do begin s := s + it.next().getInfo(self); end; currentShop := saveShop; Result := s; end; end; end.

演習問題３（レジ袋）