everything-claude-code-mobile: Skill for Claude Code

Combine Framework

Reactive programming with Apple's Combine framework.

Core Concepts

Publisher & Subscriber

// ✅ Basic subscription
let publisher = Just("Hello")
let subscriber = publisher.sink { value in
    print(value)  // "Hello"
}

Creating Publishers

// ✅ Just - single value
Just(42)

// ✅ Future - async result
Future { promise in
    promise(.success(42))
    // or
    promise(.failure(Error()))
}

// ✅ PassthroughSubject - broadcast
let subject = PassthroughSubject<String, Never>()
subject.send("Hello")
subject.send(completion: .finished)

// ✅ CurrentValueSubject - holds current value
let currentValue = CurrentValueSubject<Int, Never>(0)
currentValue.send(1)
print(currentValue.value)  // 1

// ✅ @Published in ObservableObject
class ViewModel: ObservableObject {
    @Published var count = 0
}

Common Operators

Transform

// ✅ map - transform values
[1, 2, 3].publisher
    .map { $0 * 2 }
    .sink { print($0) }  // 2, 4, 6

// ✅ flatMap - nested publishers
[1, 2, 3].publisher
    .flatMap { value in
        Future { promise in
            promise(.success(value * 2))
        }
    }
    .sink { print($0) }

// ✅ scan - accumulate
(1...10).publisher
    .scan(0, +)
    .sink { print($0) }  // 1, 3, 6, 10, 15...

Filter

// ✅ filter
(1...10).publisher
    .filter { $0 % 2 == 0 }
    .sink { print($0) }  // 2, 4, 6, 8, 10

// ✅ removeDuplicates
[1, 1, 2, 2, 3].publisher
    .removeDuplicates()
    .sink { print($0) }  // 1, 2, 3

// ✅ debounce - wait for pause
searchTextPublisher
    .debounce(for: .milliseconds(300), scheduler: RunLoop.main)
    .sink { text in
        performSearch(text)
    }

Combine

// ✅ combineLatest - waits for both
let namePublisher = CurrentValueSubject<String, Never>("")
let agePublisher = CurrentValueSubject<Int, Never>(0)

Publishers.CombineLatest(namePublisher, agePublisher)
    .sink { name, age in
        print("\(name), \(age)")
    }

// ✅ merge - same type, interleaved
let p1 = PassthroughSubject<Int, Never>()
let p2 = PassthroughSubject<Int, Never>()

p1.merge(with: p2)
    .sink { print($0) }

// ✅ zip - pairs up
let names = PassthroughSubject<String, Never>()
let ages = PassthroughSubject<Int, Never>()

names.zip(ages)
    .sink { print("\($0) is \($1) years old") }