CODESAMPLE

Microkernel - Swift

Microkernel Swift

The Microkernel pattern structures an application with a core system providing minimal functionality and extending features via plug-ins. This promotes modularity and flexibility, allowing functionalities to be added, removed, or updated without affecting the core.

This Swift example models a simple text processing application. The Kernel defines the core processing loop and handles plugin registration. Plugin is a protocol that each text processing function must conform to. Two example plugins, UppercasePlugin and LowercasePlugin, are provided. The kernel iterates through registered plugins, applying each to the input text. This implementation leverages Swift’s protocols and first-class functions for a natural and extensible approach, ideal for a dynamic system like a microkernel.

// Kernel.swift
import Foundation

protocol Plugin {
    var name: String { get }
    func process(text: String) -> String
}

class Kernel {
    private var plugins: [Plugin] = []

    func registerPlugin(_ plugin: Plugin) {
        plugins.append(plugin)
    }

    func process(text: String) -> String {
        var processedText = text
        for plugin in plugins {
            processedText = plugin.process(text: processedText)
        }
        return processedText
    }
}

// UppercasePlugin.swift
class UppercasePlugin: Plugin {
    let name = "Uppercase"
    func process(text: String) -> String {
        return text.uppercased()
    }
}

// LowercasePlugin.swift
class LowercasePlugin: Plugin {
    let name = "Lowercase"
    func process(text: String) -> String {
        return text.lowercased()
    }
}

// Example Usage:
let kernel = Kernel()
kernel.registerPlugin(UppercasePlugin())
kernel.registerPlugin(LowercasePlugin())

let input = "Hello World"
let output = kernel.process(text: input)
print(output) // Prints "hello world"