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Sergey Leschev
Sergey Leschev

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🌿 Composite Pattern

Composite Pattern

The composite pattern is used to create hierarchical, recursive tree structures of related objects where any element of the structure may be accessed and utilised in a standard manner.



protocol Shape {
    func draw(fillColor: String)
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final class Square: Shape {
    func draw(fillColor: String) {
        print("Drawing a Square with color \(fillColor)")

final class Circle: Shape {
    func draw(fillColor: String) {
        print("Drawing a circle with color \(fillColor)")
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final class Whiteboard: Shape {
    private lazy var shapes = [Shape]()

    init(_ shapes: Shape...) {
        self.shapes = shapes

    func draw(fillColor: String) {
        for shape in self.shapes {
            shape.draw(fillColor: fillColor)
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var whiteboard = Whiteboard(Circle(), Square())
whiteboard.draw(fillColor: "Red")
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Sources: Github

In software engineering, structural design patterns are design patterns that ease the design by identifying a simple way to realize relationships between entities.

🐝 Chain Of Responsibility
👫 Command Pattern
🎶 Interpreter Pattern
🍫 Iterator Pattern
💐 Mediator Pattern
💾 Memento Pattern
👓 Observer Pattern
🐉 State Pattern
💡 Strategy Pattern
📝 Template Method
🏃 Visitor Pattern
🌰 Abstract Factory
👷 Builder Pattern
🏭 Factory Method
🔂 Monostate Pattern
🃏 Prototype Pattern
💍 Singleton
🔌 Adapter Pattern
🌉 Bridge Pattern
🌿 Composite Pattern
🍧 Decorator Pattern
🎁 Facade Pattern
🍃 Flyweight Pattern
Protection Proxy
🍬 Virtual Proxy

I have a clear focus on time-to-market and don't prioritize technical debt. And I took part in the Pre-Sale/RFX activity as a System Architect, assessment efforts for Mobile (iOS-Swift, Android-Kotlin), Frontend (React-TypeScript) and Backend (NodeJS-.NET-PHP-Kafka-SQL-NoSQL). And I also formed the work of Pre-Sale as a CTO from Opportunity to Proposal via knowledge transfer to Successful Delivery.

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