From 11cb7eb330c5209253163f4fbb85ec1d7b25c9b3 Mon Sep 17 00:00:00 2001
From: syneffort <syneffort@gmail.com>
Date: Fri, 19 Aug 2022 09:56:52 +0900
Subject: [PATCH] iterator pattern

---
 DesignPattern/Iterator/Client.cs         | 23 ++++++++++++++++
 DesignPattern/Iterator/ColorAggregate.cs | 20 ++++++++++++++
 DesignPattern/Iterator/CommonIterator.cs | 35 ++++++++++++++++++++++++
 DesignPattern/Iterator/IAggregate.cs     | 13 +++++++++
 DesignPattern/Iterator/IIterator.cs      | 15 ++++++++++
 DesignPattern/Iterator/Iterator.csproj   |  5 ++++
 DesignPattern/Iterator/Program.cs        |  3 ++
 7 files changed, 114 insertions(+)
 create mode 100644 DesignPattern/Iterator/Client.cs
 create mode 100644 DesignPattern/Iterator/ColorAggregate.cs
 create mode 100644 DesignPattern/Iterator/CommonIterator.cs
 create mode 100644 DesignPattern/Iterator/IAggregate.cs
 create mode 100644 DesignPattern/Iterator/IIterator.cs

diff --git a/DesignPattern/Iterator/Client.cs b/DesignPattern/Iterator/Client.cs
new file mode 100644
index 0000000..62eaf74
--- /dev/null
+++ b/DesignPattern/Iterator/Client.cs
@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Iterator
+{
+    internal class Client
+    {
+        public static void HowToTest()
+        {
+            IAggregate agg = new ColorAggregate();
+            IIterator iter = agg.GetIterator();
+
+            object c1 = iter.Next();
+            object c2 = iter.Next();
+            object c3 = iter.Next();
+
+            Console.WriteLine($"{c1}, {c2}, {c3}");
+        }
+    }
+}
diff --git a/DesignPattern/Iterator/ColorAggregate.cs b/DesignPattern/Iterator/ColorAggregate.cs
new file mode 100644
index 0000000..8cf46c9
--- /dev/null
+++ b/DesignPattern/Iterator/ColorAggregate.cs
@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Iterator
+{
+    internal class ColorAggregate : IAggregate
+    {
+        object[] colors = { "White", "Red", "Green", "Blue", "Black" };
+
+        public IIterator GetIterator()
+        {
+            return new CommonIterator(colors);
+        }
+
+        public int Count { get { return colors.Length; } }
+    }
+}
diff --git a/DesignPattern/Iterator/CommonIterator.cs b/DesignPattern/Iterator/CommonIterator.cs
new file mode 100644
index 0000000..47365c1
--- /dev/null
+++ b/DesignPattern/Iterator/CommonIterator.cs
@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Iterator
+{
+    internal class CommonIterator : IIterator
+    {
+        private object[] collection;
+        private int index;
+
+        public CommonIterator(object[] collection)
+        {
+            this.collection = collection;
+            this.index = -1;
+        }
+
+        public bool HasNext { get { return index + 1 < collection.Length; } }
+
+        public object Next()
+        {
+            if (HasNext)
+            {
+                index++;
+                return collection[index];
+            }
+            else
+            {
+                return null;
+            }
+        }
+    }
+}
diff --git a/DesignPattern/Iterator/IAggregate.cs b/DesignPattern/Iterator/IAggregate.cs
new file mode 100644
index 0000000..570c35e
--- /dev/null
+++ b/DesignPattern/Iterator/IAggregate.cs
@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Iterator
+{
+    internal interface IAggregate
+    {
+        IIterator GetIterator();
+    }
+}
diff --git a/DesignPattern/Iterator/IIterator.cs b/DesignPattern/Iterator/IIterator.cs
new file mode 100644
index 0000000..6061f76
--- /dev/null
+++ b/DesignPattern/Iterator/IIterator.cs
@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Iterator
+{
+    internal interface IIterator
+    {
+        bool HasNext { get; }
+        
+        object Next();
+    }
+}
diff --git a/DesignPattern/Iterator/Iterator.csproj b/DesignPattern/Iterator/Iterator.csproj
index e03ce46..cc1273a 100644
--- a/DesignPattern/Iterator/Iterator.csproj
+++ b/DesignPattern/Iterator/Iterator.csproj
@@ -43,6 +43,11 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Client.cs" />
+    <Compile Include="ColorAggregate.cs" />
+    <Compile Include="CommonIterator.cs" />
+    <Compile Include="IAggregate.cs" />
+    <Compile Include="IIterator.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
diff --git a/DesignPattern/Iterator/Program.cs b/DesignPattern/Iterator/Program.cs
index 2a89267..764fd48 100644
--- a/DesignPattern/Iterator/Program.cs
+++ b/DesignPattern/Iterator/Program.cs
@@ -16,6 +16,9 @@ namespace Iterator
     {
         static void Main(string[] args)
         {
+            Client.HowToTest();
+
+            Console.ReadKey();
         }
     }
 }