Paul pauljohanneskraft

Regex Matching in Swift using switch-case like syntax

Scenario

In this short bit, we want to decide whether a string is a phone number or an email address and create a value from this enum based on a string. We further created the two regexes to detect the different types - they may not be perfect, but this isn't the focus of this bit.

enum ContactPoint {
    case phoneNumber(String)
    case emailAddress(local: String, domain: String)

With the introduction of async/await, you might wonder how you can use the new feature in combination with Combine.

The code posted below allows you to write the following constructs:

let somePublisher = [1, 2, 3].publisher

func someAsyncFunction(_ int: Int) async -> Int {
    return int
}

ScreenMonitoringNotifier

ScreenMonitoringNotifier uses a timer with a specific timeInterval - default is 1 second - to check whether any screen is potentially being monitored. Potentially being monitored includes active screen recordings and the use of external displays.

Use ScreenMonitoringNotifier.shared to send out notifications or instantiate your own ScreenMonitoringNotifier to use callbacks.

Either

Use Either to allow multiple result types to be combined into one. You can then switch over the specific types to evaluate the result. Either can be used as described below.

let _b = false

func b() -> Either<String, Int> {
    if _b {
 return *""

(Sparse) Memoizer

Initialization

let fibonacci = memoize { x, op in x < 2 ? x : op(x-1) + op(x-2) }
let fibonacciSparse = sparseMemoize(when: { $0 % 3 != 0 }) { x, op in x < 2 ? x : op(x-1) + op(x-2) }

Use

ALU in VHDL

This is an implementation of a 16-bit ALU in VHDL.

Inputs

Name	Purpose	Size
R, S	operands	16-bit integer
I	operation	3-bit

DayOfTheWeek

This function returns the weekday of any date between 1700 and 2199.

print(try dayOfTheWeek("28.09.1964")) // Prints "Monday"
print(try dayOfTheWeek("12.03.2014")) // Prints "Wednesday"
print(try dayOfTheWeek("31.12.1980")) // Prints "Wednesday"

String Replacer

enables fast switching between certain letters in Strings

var s = StringReplacer(("E", "3"), ("g", "9"), ("O", "0"), ("o", "0"), ("l", "1"))

s["1"] = "l"

var str = "hallo"

Cached Properties

Complicated, time expensive computed properties can be cached using the following pattern.

var a = Cached(0) {
    (a: Int) -> Int in
    print("did calculate")
    return a + 100
}

	struct KeychainItem {

	// MARK: Nested Types

	enum KeychainError: Error {
	case noPassword
	case unexpectedPasswordData
	case unexpectedItemData
	case unhandledError(status: OSStatus)
	}