readme.md

S.Leschev Design Patterns (Swift 5+)

Google Engineering Level: L6+

🏆 Awards

Ranking #Dev: Global TOP 300 (Certificate)

Languages: Swift, Shell, Database (T-SQL, PL/SQL, MySQL), Concurrency (Python3).

Algorithms: linked lists, binary search, hash table, queue/stack, dfs/bfs, sort, heap/hash, two pointers, sliding window, tree, greedy problems etc.

👫 Command

The command pattern is used to express a request, including the call to be made and all of its required parameters, in a command object. The command may then be executed immediately or held for later use.

Example:

protocol DoorCommand {
    func execute() -> String
}

final class OpenCommand: DoorCommand {
    let doors:String

    required init(doors: String) {
        self.doors = doors
    }
    
    func execute() -> String {
        return "Opened \(doors)"
    }
}

final class CloseCommand: DoorCommand {
    let doors:String

    required init(doors: String) {
        self.doors = doors
    }
    
    func execute() -> String {
        return "Closed \(doors)"
    }
}

final class HAL9000DoorsOperations {
    let openCommand: DoorCommand
    let closeCommand: DoorCommand
    
    init(doors: String) {
        self.openCommand = OpenCommand(doors:doors)
        self.closeCommand = CloseCommand(doors:doors)
    }
    
    func close() -> String {
        return closeCommand.execute()
    }
    
    func open() -> String {
        return openCommand.execute()
    }
}

Usage:

let podBayDoors = "Pod Bay Doors"
let doorModule = HAL9000DoorsOperations(doors:podBayDoors)

doorModule.open()
doorModule.close()

Contacts

I have a clear focus on time-to-market and don't prioritize technical debt.

🛩️ #startups #management #cto #swift #typescript #database

📧 Email: sergey.leschev@gmail.com

👋 LinkedIn: https://linkedin.com/in/sergeyleschev

👋 Twitter: https://twitter.com/sergeyleschev

👋 Github: https://github.com/sergeyleschev

🌎 Website: https://sergeyleschev.github.io

🖨️ PDF: Download

ALT: SIARHEI LIASHCHOU