Skip to content

Instantly share code, notes, and snippets.

@cprovatas
cprovatas / Array+Spread.swift
Last active July 22, 2023 02:04
Spread Syntax for Swift Arrays (ala es6)
extension Array {
static func ... (lhs: [Self.Element], rhs: [Self.Element]) -> [Self.Element] {
var copy = lhs
copy.append(contentsOf: rhs)
return copy
}
static func ... (lhs: Self.Element, rhs: [Self.Element]) -> [Self.Element] {
var copy = [lhs]
copy.append(contentsOf: rhs)
@cprovatas
cprovatas / SequenceHelpers.swift
Last active October 12, 2019 07:22
Swift Sequence Helpers
// These helpers allow for basic operations to be performed while still iterating over a sequence once without
// adding all of the common boilerplate code you'd normally have to write
extension Sequence {
// filter + forEach
func forEach(where predicate: (Element) -> Bool, _ body: (Element) throws -> Void) rethrows {
for element in self where predicate(element) {
try body(element)
}
}
@cprovatas
cprovatas / interpolation.swift
Created June 8, 2019 22:56
Decorating Command Line Output With DefaultStringInterpolation
enum ASCIIColor: String {
case black = "\u{001B}[0;30m"
case red = "\u{001B}[0;31m"
case green = "\u{001B}[0;32m"
case yellow = "\u{001B}[0;33m"
case blue = "\u{001B}[0;34m"
case magenta = "\u{001B}[0;35m"
case cyan = "\u{001B}[0;36m"
case white = "\u{001B}[0;37m"
case `default` = "\u{001B}[0;0m"
@cprovatas
cprovatas / TypeReflectable.swift
Last active October 20, 2018 22:28
Access current type by calling Self instead of manually calling <current type>.self
protocol TypeReflectable {
var `Self`: Self.Type { get }
static var `Self`: Self.Type { get }
}
extension TypeReflectable {
var `Self`: Self.Type {
return type(of: self)
}
@cprovatas
cprovatas / CGImage+Utilities.swift
Last active July 6, 2018 23:00
Determine if a CGImage is completely white
import UIKit
extension CGImage {
var isBlank: Bool {
guard let data = dataProvider?.data, let buffer = CFDataGetBytePtr(data) else { return false }
let length = CFDataGetLength(data)
var i = 0
while i < length {
if buffer[i] < 255, buffer[i + 1] < 255, buffer[i + 2] < 255 {
return false
@cprovatas
cprovatas / Data+PrettyPrint.swift
Created May 23, 2018 15:52
Pretty print JSON string from Data in Swift 4.1 (especially useful printing to Xcode console)
import Foundation
extension Data {
var prettyPrintedJSONString: NSString? { /// NSString gives us a nice sanitized debugDescription
guard let object = try? JSONSerialization.jsonObject(with: self, options: []),
let data = try? JSONSerialization.data(withJSONObject: object, options: [.prettyPrinted]),
let prettyPrintedString = NSString(data: data, encoding: String.Encoding.utf8.rawValue) else { return nil }
return prettyPrintedString
}
@cprovatas
cprovatas / Throttle.swift
Last active April 9, 2018 19:46
Throttle , similar to RxSwift's throttle but can be used on any arbitrary block
/// throttle a procedure for the given time interval, operation identifer is used to uniquely identify operation to prevent from firing multiple times
private var throttledOperations: Set<String> = []
func dispatchThrottle(_ interval: TimeInterval, operationIdentifier: String, queue: DispatchQueue = .main, _ closure: @escaping () -> Void) {
guard !throttledOperations.contains(operationIdentifier) else { return }
throttledOperations.insert(operationIdentifier)
closure()
queue.asyncAfter(deadline: .now() + interval) {
throttledOperations.remove(operationIdentifier)
}
}
@cprovatas
cprovatas / Trim.swift
Created March 8, 2018 16:40
trim null values out of a dictionary in Swift 4
//Uses only O(n) complexity.
extension Dictionary where Key == String, Value == Any? {
var trimmingNullValues: [String: Any] {
var copy = self
forEach { (key, value) in
if value == nil {
copy.removeValue(forKey: key)
}
@cprovatas
cprovatas / RoundedSecond.swift
Created February 21, 2018 19:06
Round Date to Second
extension Date {
var roundedToSecond: Date {
let date = self
let diff = 1000000000 - Calendar.current.component(.nanosecond, from: date)
return Calendar.current.date(byAdding: .nanosecond, value: diff, to: date)!
}
}
/// USAGE:
let roundedDate = Date().roundedToSecond /// zero nanoseconds
@cprovatas
cprovatas / TopLevelCollection.swift
Created January 19, 2018 23:05
Auto-implement class/struct as envelope for top level arrays in JSON by implementing this simple protocol
protocol TopLevelCollection: Codable {
associatedtype ElementType: Codable
var elements: [ElementType] { get set }
init(elements: [ElementType])
}
extension TopLevelCollection {
public init(from decoder: Decoder) throws {
var container = try decoder.unkeyedContainer()