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Sergey Leschev
Sergey Leschev

Posted on • Updated on

💡 Strategy Pattern

Strategy Pattern

The strategy pattern is used to create an interchangeable family of algorithms from which the required process is chosen at run-time.



struct TestSubject {
    let pupilDiameter: Double
    let blushResponse: Double
    let isOrganic: Bool

protocol RealnessTesting: AnyObject {
    func testRealness(_ testSubject: TestSubject) -> Bool

final class VoightKampffTest: RealnessTesting {
    func testRealness(_ testSubject: TestSubject) -> Bool {
        return testSubject.pupilDiameter < 30.0 || testSubject.blushResponse == 0.0
final class GeneticTest: RealnessTesting {
    func testRealness(_ testSubject: TestSubject) -> Bool {
        return testSubject.isOrganic
final class BladeRunner {
    private let strategy: RealnessTesting
    init(test: RealnessTesting) { self.strategy = test }
    func testIfAndroid(_ testSubject: TestSubject) -> Bool {
        return !strategy.testRealness(testSubject)
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let rachel = TestSubject(pupilDiameter: 30.2,
                         blushResponse: 0.3,
                         isOrganic: false)

// Deckard is using a traditional test
let deckard = BladeRunner(test: VoightKampffTest())
let isRachelAndroid = deckard.testIfAndroid(rachel)

// Gaff is using a very precise method
let gaff = BladeRunner(test: GeneticTest())
let isDeckardAndroid = gaff.testIfAndroid(Rachel)
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Sources: Github

In software engineering, behavioral design patterns are design patterns that identify common communication patterns between objects and realize these patterns. By doing so, these patterns increase flexibility in carrying out this communication.

🐝 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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