Skip to content

Instantly share code, notes, and snippets.

staltz /
Last active Dec 1, 2021
The introduction to Reactive Programming you've been missing
tclementdev /
Last active Dec 1, 2021
Making efficient use of the libdispatch (GCD)

libdispatch efficiency tips

The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).

My take-aways are:

  • You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.

  • Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse

zntfdr / firebase-iOS-breakdown.swift
Last active Nov 30, 2021
Firebase iOS Version breakdown
View firebase-iOS-breakdown.swift
// How to:
// 1. Open the Firebase Analytics Dashboard
// 2. Scroll to bottom, where you see the "Users by Device model" widget
// 3. Click "View device models" in that widget (this opens the "Tech details" Firebase Analytics page)
// 4. Above the table shown in the new page, click on the “Device model” drop down menu and select “OS with Version”
// 5. Make sure to select “OS with version” and not “OS Version”
// 6. On the top right corner of the page, click on the “Share comparison” icon (next to the date)
// 7. Click “Download file” on the new side bar, then “Download CSV"
// 8. Open the file and select the iOS/Android breakdown raw data
// 9. Replace the sample data in this script with your data
iPaulPro / include_list_viewpager.xml
Last active Nov 29, 2021
CollapsingToolbarLayout with TabLayout
View include_list_viewpager.xml
<?xml version="1.0" encoding="utf-8"?><!--
~ Copyright (C) 2015 The Android Open Source Project
~ Licensed under the Apache License, Version 2.0 (the "License");
~ you may not use this file except in compliance with the License.
~ You may obtain a copy of the License at
~ Unless required by applicable law or agreed to in writing, software
simonbs / UserDefault.swift
Last active Nov 27, 2021
Property wrapper that stores values in UserDefaults and works with SwiftUI and Combine.
View UserDefault.swift
* I needed a property wrapper that fulfilled the following four requirements:
* 1. Values are stored in UserDefaults.
* 2. Properties using the property wrapper can be used with SwiftUI.
* 3. The property wrapper exposes a Publisher to be used with Combine.
* 4. The publisher is only called when the value is updated and not
* when_any_ value stored in UserDefaults is updated.
* First I tried using SwiftUI's builtin @AppStorage property wrapper
View boilerplate.swift
// Run any SwiftUI view as a Mac app.
import Cocoa
import SwiftUI {
VStack {
Text("Hello, World")
steipete / RandomColor.swift
Created Apr 6, 2021
Random Color for SwiftUI
View RandomColor.swift
extension Color {
/// Return a random color
static var random: Color {
return Color(
red: .random(in: 0...1),
green: .random(in: 0...1),
blue: .random(in: 0...1)
gubatron /
Last active Nov 19, 2021
How to configure multiple deploy keys for different private github repositories on the same computer without using ssh-agent

How to configure multiple deploy keys for different private github repositories on the same computer without using ssh-agent

Let's say alice is a user, with 2 or more private repositories repoN. For this example we'll work with just two repositories named repo1 and repo2

You need to be to pull from these repositories without entering a passwords probably on a server, or on multiple servers.