Keita Ito keitaito

Scrabs from : https://gist.github.com/jsturgis/3b19447b304616f18657

State of String: ABI, Performance, Ergonomics, and You!

Hello, I’ve been working on implementing, optimizing, and improving String in preparation for ABI stability, and I thought I’d share the current status of String in Swift 5 and some potential directions to go. This is the product of conversations with open source contributors and my colleagues on the Swift standard library team at Apple.

The primary area of focus is stabilizing String’s ABI, but we’d be remiss if we couldn’t also fit in performance and ergonomic improvements. String’s ergonomics in particular is one area where we think the status quo is woefully inadequate, and over half of this email is devoted to that topic. At the end, there’s a section about a community initiative that we hope can help users of String as well as guide future development.

(Note: I’m sending this to swift-dev because much of the contents revolve around implementation concerns. I’ll also cross-reference on swift-evolution and swift-users. See also the [StringManife

Typed error can be useful in certain cases, especially when accompanied with NoError type.

For example, in reactive programming, https://github.com/ReactiveCocoa/ReactiveSwift (typed error) allows us to create UI bindings only if Error is NoError, i.e.:

static func <~ <Source: BindingSource> (provider: Self, source: Source) -> Disposable? 
    where Source.Value == Value, Source.Error == NoError { ... }
    
// example
let alphaSignal: Signal = ...

Keychain API

kSecAttrAccessible Mapping

Protection Domain (pdmn)	Keychain Accessibility Values
`ck`	`kSecAttrAccessibleAfterFirstUnlock`
`cku`	`kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly`
`dk`	`kSecAttrAccessibleAlways`
`akpu`	`kSecAttrAccessibleWhenPasscodeSetThisDeviceOnly`

	#!/usr/bin/env sh

	set -e

	fancy_echo() {
	local fmt="$1"; shift

	printf "\n$fmt\n" "$@"
	}

	import Foundation

	/// An abstract class that makes building simple asynchronous operations easy.
	/// Subclasses must override `main()` to perform any work and call `finish()`
	/// when they are done. All `NSOperation` work will be handled automatically.
	///
	/// Source/Inspiration: https://stackoverflow.com/a/48104095/116862 and https://gist.github.com/calebd/93fa347397cec5f88233
	open class AsyncOperation: Operation {
	public init(name: String? = nil) {
	super.init()

	Originall From: Posted 2015-05-29 http://ubwg.net/b/full-list-of-ffmpeg-flags-and-options

	This is the complete list that’s outputted by ffmpeg when running ffmpeg -h full.

	usage: ffmpeg [options] [[infile options] -i infile]… {[outfile options] outfile}…

	Getting help:
	-h — print basic options
	-h long — print more options
	-h full — print all options (including all format and codec specific options, very long)

	let str = "acxz"

	func isFunny(_ s: AnySequence<UInt8>) -> Bool {
	let n1: [Int] = zip(s.dropFirst(), s).map { Int($0)-Int($1) }
	let n2: [Int] = zip(s.reversed().dropFirst(), s.reversed()).map { Int($1)-Int($0) }
	return n1 == n2
	}

	isFunny(AnySequence(str.utf8))

	[
	{"url": "https://devstreaming-cdn.apple.com/videos/wwdc/2018/236mwbxbxjfsvns4jan/236/236_hd_avspeechsynthesizer_making_ios_talk.mp4?dl=1", "title": "AVSpeechSynthesizer: Making iOS Talk", "summary": "Speech can enhance the audio experience of your app, whether you are generating spoken feedback for accessibility, or providing critical information beyond simple alerts or notifications. AVSpeechSynthesizer produces synthesized speech from text and allows you to control and monitor the progress of ongoing speech. Learn the ins and outs of AVSpeechSynthesizer and how to add computer-generated speech output to your app."},
	{"url": "https://devstreaming-cdn.apple.com/videos/wwdc/2018/405bjty1j94taqv8ii/405/405_hd_measuring_performance_using_logging.mp4?dl=1", "title": "Measuring Performance Using Logging", "summary": "Learn how to use signposts and logging to measure performance. Understand how the Points of Interest instrument can be used to examine logged data. Get an introduction into creating and using custo