delebedev

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:

delebedev

Javascript is fun

a = new Date('2019-03-31T00:00:00.000Z');
a.setDate(a.getDate() + 1);
console.log(a);

Firefox macos	Safari macos	chrome macos

delebedev

#!/usr/bin/env python

import lldb

def process(debugger, command, result, internal_dict):
    lldb.debugger.HandleCommand("""
expr -l swift --
func $process(_ request: URLRequest) {
    func curl(_ request: URLRequest) -> String {
        guard let url = request.url?.absoluteString else {

delebedev

struct MinimalDecoder : Decoder {
  var codingPath = [CodingKey?]()
  var userInfo = [CodingUserInfoKey : Any]()
  
  public func container<Key>(keyedBy type: Key.Type) throws -> KeyedDecodingContainer<Key> {
    return KeyedDecodingContainer(MinimalKeyedDecodingContainer<Key>(decoder: self))
  }
  
  public func unkeyedContainer() throws -> UnkeyedDecodingContainer {
    return DecodingContainer(decoder: self)

delebedev

// Class Keyword: NSManagedObject is defined in objective-c (not sure if it matters)
// .keywords is CoreData to-many relationship pointing to "Keyword" objects. 

// How do I convert .keywords to [Keyword]?

po type(of: keywords)
_NSFaultingMutableOrderedSet

po keywords is NSOrderedSet
true

delebedev

Adyen Test Card Numbers
These cards are only valid on our TEST system and they will never involve any actual transaction or transfer of funds. The TEST card numbers will not work on the Adyen LIVE Platform.

For all cards use the following expiration and CVV2/CVC2/or CID for Amex. 

For all cards:

Expiration Dates	CVV2 / CVC3	CID (American Express)
06/2016  OR  08/2018	737	7373

delebedev

Types

A type is a collection of possible values. An integer can have values 0, 1, 2, 3, etc.; a boolean can have values true and false. We can imagine any type we like: for example, a HighFive type that allows the values "hi" or 5, but nothing else. It's not a string and it's not an integer; it's its own, separate type.

Statically typed languages constrain variables' types: the programming language might know, for example, that x is an Integer. In that case, the programmer isn't allowed to say x = true; that would be an invalid program. The compiler will refuse to compile it, so we can't even run it.

delebedev

import Result
import Unbox

public enum Method: String { // Bluntly stolen from Alamofire
    case OPTIONS = "OPTIONS"
    case GET = "GET"
    case HEAD = "HEAD"
    case POST = "POST"
    case PUT = "PUT"
    case PATCH = "PATCH"

delebedev

#!/usr/bin/env ruby

require 'net/http'
require 'json'
require 'ostruct'
require 'fileutils'

PATH = "https://devimages.apple.com.edgekey.net/wwdc-services/ftzj8e4h/6rsxhod7fvdtnjnmgsun/videos.json"
WWDC_DIR = "#{Dir.home}/Downloads/wwdc"

delebedev

//
//  main.swift
//  ForsquareGPX
//
//  Created by Dzianis Lebedzeu on 07/06/2015.
//  Copyright (c) 2015 Home. All rights reserved.
//

import Foundation