Krishna

Learn Go in ~5mins

This is inspired by A half-hour to learn Rust and Zig in 30 minutes.

Basics

Your first Go program as a classical "Hello World" is pretty simple:

First we create a workspace for our project:

Krishna

import SwiftUI

fileprivate extension DateFormatter {
    static var month: DateFormatter {
        let formatter = DateFormatter()
        formatter.dateFormat = "MMMM"
        return formatter
    }

    static var monthAndYear: DateFormatter {

Krishna

import Foundation

// Source: https://stackoverflow.com/a/39425959

extension Character {
    /// A simple emoji is one scalar and presented to the user as an Emoji
    var isSimpleEmoji: Bool {
        guard let firstScalar = unicodeScalars.first else { return false }
        return firstScalar.properties.isEmoji && firstScalar.value > 0x238C
    }

Krishna

# File: app/controllers/api/api_controller.rb
class Api::ApiController < ActionController::Base
  # Consider subclassing ActionController::API instead of Base, see
  # http://api.rubyonrails.org/classes/ActionController/API.html
  
  protect_from_forgery with: :null_session
  before_action :authenticate
  
  def self.disable_turbolinks_cookies
    skip_before_action :set_request_method_cookie

Krishna

export function clapperBoard() {
  let audio = new AudioContext()
  let beep  = audio.createOscillator()
  let flash = document.createElement("div")

  beep.frequency.value = 440 * 5
  beep.connect(audio.destination)
  flash.classList.add("clapperboard")

  beep.start()

Krishna

libdispatch efficiency tips

I suspect most developers are using the libdispatch inefficiently due to the way it was presented to us at the time it was introduced and for many years after that, and due to the confusing documentation and API. I realized this after reading the 'concurrency' discussion on the swift-evolution mailing-list, in particular the messages from Pierre Habouzit (who is the libdispatch maintainer at Apple) are quite enlightening (and you can also find many tweets from him on the subject).

• https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20170828/date.html
• https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20170904/date.html
• https://twitter.com/pedantcoder

My take-aways are:

Krishna

Cheat Sheet: Simple Authentication in Rails 5 with has_secure_password

The goal of this cheatsheet is to make it easy to add hand-rolled authentication to any rails app in a series of layers.

First the simplest/core layers, then optional layers depending on which features/functionality you want.

Specs
AUTHOR	Ira Herman
LANGUAGE/STACK	Ruby on Rails Version 4 or 5

Krishna

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[])
{
   NSRunLoop   * runLoop;
   CLIMain     * main; // replace with desired class

   @autoreleasepool
   {
      // create run loop

Krishna

#import <Foundation/Foundation.h>

@interface SafeSet : NSObject {
    NSMutableSet *set;
    dispatch_queue_t queue;
}
@end

@implementation SafeSet

Krishna

/*
    Copyright (C) 2016 Apple Inc. All Rights Reserved.
    See LICENSE.txt for this sample’s licensing information

    Abstract:
    `DirectoryMonitor` is used to monitor the contents of the provided directory by using a GCD dispatch source.
*/

import Foundation