davbeck

struct Lock {
	private var unfairLock = os_unfair_lock_s()
	
	mutating func lock(_ work: () -> Void) {
		self.lock()
		work()
		self.unlock()
	}
	
	mutating func trylock(_ work: () -> Void) -> Bool {

davbeck

import ObjectiveC


extension objc_AssociationPolicy {
	public static let retain = objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN
	public static let retainNonatomic = objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC
	public static let copy = objc_AssociationPolicy.OBJC_ASSOCIATION_COPY
	public static let copyNonatomic = objc_AssociationPolicy.OBJC_ASSOCIATION_COPY_NONATOMIC
	public static let assign = objc_AssociationPolicy.OBJC_ASSOCIATION_ASSIGN
}

davbeck

import Foundation

/// Allows a property to fail decoding, defaulting to nil instead of surfacing the error.
@propertyWrapper
struct AllowDecodeFailure<Wrapped>: Codable where Wrapped: Codable {
	var wrappedValue: Wrapped?
	
	init() {
		self.wrappedValue = nil
	}

davbeck

func _if<T>(_ test: Bool, action: () -> T) -> T? {
	if test {
		return action()
	} else {
		return nil
	}
}

extension Optional {
	func _else(action: () -> Wrapped) -> Wrapped {

davbeck

extension Collection where Element: FloatingPoint {
	func average() -> Element {
		return self.reduce(Element.zero, +) / Element(self.count)
	}
}

extension Collection where Element: BinaryInteger {
	func average() -> Double {
		return Double(self.reduce(0, +)) / Double(self.count)
	}

davbeck

import PlaygroundSupport

let limiter = RateLimiter(timeframe: 5)

PlaygroundPage.current.needsIndefiniteExecution = true

for i in 0..<100 {
	limiter.perform {
		print("perform", i)
	}

davbeck

struct Parent: View {
	@State var count: Int = 0
	var body: some View {
		return VStack {
			ImageLoadingView(url: URL(string: "https://github.com/recurser/exif-orientation-examples/blob/9c4ccfaea6bfd434ac1c4bb0750ac6fc5848a5f4/Landscape_8.jpg?raw=true")!)
			Text("counter: \(count)")
		}
		.onAppear {
			Timer.scheduledTimer(withTimeInterval: 5, repeats: true) { (timer) in
				self.count += 1

davbeck

/// The result of a binary search.
struct BinarySearchResult<Index> {
	/// The index for the searched key.
	///
	/// Use this to either insert new values while maintaining the sort order of the collection, or to lookup the value if `isPresent` is true.
	var index: Index
	
	/// Whether the key was found in the collection.
	///
	/// When performing a binary search, even if the value is not found in the collection, an index is returned which can be used to insert a new item at the correct location.

davbeck

// adapted from https://github.com/raywenderlich/swift-algorithm-club/tree/master/Binary%20Search

/// The result of a binary search.
struct BinarySearchResult<Index> {
	/// The index for the searched key.
	///
	/// Use this to either insert new values while maintaining the sort order of the collection, or to lookup the value if `isPresent` is true.
	var index: Index
	
	/// Whether the key was found in the collection.

davbeck

import Foundation
import SQLite3


public enum SQLiteError: Error, LocalizedError {
	case sqlite(code: Int32, message: String?)
	case invalidDatabase
	case invalidStatement
	case invalidUTF8String