interpreter, observer, memento, mediator

Author: T0shik

README.md

@@ -29,3 +29,6 @@ Full Playlist can be found [here](https://www.youtube.com/playlist?list=PLOeFnOV
 - [Interpreter](https://youtu.be/Vc3aiaAcIME)
 - [Chain of Responsibility](https://youtu.be/YQ03IyRu1Zo)
 - [Command](https://youtu.be/nW2ahdZojho)
+- [Mediator](https://youtu.be/VYLD75sU1rw)
+- [Memento](https://youtu.be/SAaIsErpGDY)
+- [Observer](https://youtu.be/8nICu7ZSPtE)

interpreter/domain_language.linq

@@ -0,0 +1,47 @@
+<Query Kind="Program" />
+
+void Main()
+{
+	// Language
+	var domainLanguage = "order x10 '2L water bottles' from Tesco";
+	Order.Parse(domainLanguage).Dump();
+}
+
+// Grammar Representation
+const string optionalSpace = " ?";
+const string qty = "x(?<qty>\\d+)" + optionalSpace;
+const string product = "'(?<product>[\\w ]+)'" + optionalSpace;
+const string source = "from (?<source>\\w+)";
+const string orderCommand = "order" + optionalSpace + qty + product + source;
+
+public class Order
+{
+	static Regex _regex = new Regex(orderCommand);
+
+	Order(int qty, string product, string source)
+	{
+		Qty = qty;
+		Product = product;
+		Source = source;
+	}
+
+	public int Qty { get; }
+	public string Product { get; }
+	public string Source { get; }
+
+	// Interpreter
+	public static Order Parse(string command)
+	{
+		var match = _regex.Match(command);
+		if (!match.Success)
+		{
+			return null;
+		}
+
+		var qty = int.Parse(match.Groups["qty"].Value);
+		var product = match.Groups["product"].Value;
+		var source = match.Groups["source"].Value;
+
+		return new Order(qty, product, source);
+	}
+}

mediator/intro.linq

@@ -0,0 +1,51 @@
+<Query Kind="Program" />
+
+void Main()
+{
+	
+}
+
+public interface IMediator{
+	public void Interaction();
+}
+
+public class Mediator : IMediator
+{
+	public Piece piece;
+	public Part part;
+	public Thing thing;
+	
+	public Mediator()
+	{
+		// setup components	
+	}
+	
+	public void Interaction()
+	{
+		
+	}
+}
+
+public class Piece
+{
+	IMediator mediator;
+	public Piece(IMediator mediator) => this.mediator = mediator;
+	
+	public void Invoke(){
+		mediator.Interaction();
+	}
+}
+
+public class Part
+{
+	IMediator mediator;
+	public Part(IMediator mediator) => this.mediator = mediator;
+
+}
+
+public class Thing
+{
+	IMediator mediator;
+	public Thing(IMediator mediator) => this.mediator = mediator;
+
+}

mediator/problem.linq

@@ -0,0 +1,52 @@
+<Query Kind="Program" />
+
+void Main()
+{
+
+}
+
+public class Product
+{
+	public int Id { get; set; }
+}
+
+public class Cart
+{
+	List<Product> products;
+
+	public void AddProduct(Product product)
+	{
+		products.Add(product);
+	}
+}
+
+public class Catalog
+{
+	List<Product> products;
+	
+	public List<Product> getProducts(){
+		return products;
+	}
+}
+
+public class ProductPage
+{ 
+	Cart cart;
+	Catalog catalog;
+
+	public ProductPage(Catalog catalog, Cart cart)
+	{
+		this.cart = cart;
+		this.catalog = catalog;
+	}
+
+	public void AddToCart(int id)
+	{
+		var product = catalog.getProducts().First(x => x.Id == id);
+		cart.AddProduct(product);
+	}
+	
+	public void DisplayProducts(){
+		// set ui elements from catalog
+	}
+}

mediator/solution.linq

@@ -0,0 +1,63 @@
+<Query Kind="Program" />
+
+void Main()
+{
+
+}
+
+public class Product
+{
+	public int Id { get; set; }
+}
+
+public class ShopContext {
+	Cart cart; 
+	Catalog catalog; 
+	ProductPage page;
+	
+	public ShopContext(Cart cart, Catalog catalog, ProductPage page)
+	{
+		this.cart = cart;
+		this.catalog = catalog;
+		this.page = page;
+		
+		this.page.DisplayProducts(catalog.getProducts());
+	}
+
+	public void AddToCart(int id)
+	{
+		cart.AddProduct(catalog.getProducts().First(x => x.Id == id));
+	}
+}
+
+public class Cart
+{
+	List<Product> products;
+
+	public void AddProduct(Product product)
+	{
+		products.Add(product);
+	}
+}
+
+public class Catalog
+{
+	List<Product> products;
+	
+	public List<Product> getProducts(){
+		return products;
+	}
+}
+
+public class ProductPage
+{
+	ShopContext context;
+	public ProductPage(ShopContext context) => this.context = context;
+
+	public void AddToCart(int id) => context.AddToCart(id);
+
+	public void DisplayProducts(List<Product> products)
+	{
+		// set ui elements
+	}
+}

mediator/solution_with_interface.linq

@@ -0,0 +1,67 @@
+<Query Kind="Program" />
+
+void Main()
+{
+
+}
+
+public class Product
+{
+	public int Id { get; set; }
+}
+
+public interface ICartInteraction {
+	void AddToCart(int id);
+}
+
+public class ShopContext : ICartInteraction {
+	Cart cart; 
+	Catalog catalog; 
+	ProductPage page;
+	
+	public ShopContext(Cart cart, Catalog catalog, ProductPage page)
+	{
+		this.cart = cart;
+		this.catalog = catalog;
+		this.page = page;
+		
+		this.page.DisplayProducts(catalog.getProducts());
+	}
+
+	public void AddToCart(int id)
+	{
+		cart.AddProduct(catalog.getProducts().First(x => x.Id == id));
+	}
+}
+
+public class Cart
+{
+	List<Product> products;
+
+	public void AddProduct(Product product)
+	{
+		products.Add(product);
+	}
+}
+
+public class Catalog
+{
+	List<Product> products;
+	
+	public List<Product> getProducts(){
+		return products;
+	}
+}
+
+public class ProductPage
+{
+	ICartInteraction cart;
+	public ProductPage(ICartInteraction cart) => this.cart = cart;
+
+	public void AddToCart(int id) => cart.AddToCart(id);
+
+	public void DisplayProducts(List<Product> products)
+	{
+		// set ui elements
+	}
+}

mediator/with_mediator.linq

@@ -0,0 +1,32 @@
+<Query Kind="Program" />
+
+void Main()
+{
+	
+}
+
+public class LogicA {
+	
+	Mediator m;
+
+	public void Do(){
+		m.DoLogic("b");
+	}
+}
+
+public class Mediator {
+	
+	public void DoLogic(string logic){
+		if(logic == "b"){
+			new LogicB().Do();
+		}
+	}
+}
+
+public class LogicB
+{
+	public void Do()
+	{
+
+	}
+}

mediator/without_mediator.linq

@@ -0,0 +1,23 @@
+<Query Kind="Program" />
+
+void Main()
+{
+	
+}
+
+public class LogicA {
+
+	LogicB b;
+
+	public void Do(){
+		b.Do();
+	}
+}
+
+public class LogicB
+{
+	public void Do()
+	{
+
+	}
+}