Will Townsend wtsnz

Locked state transitions in Ash: making "confirm payment" run exactly once

Drafted with an AI assistant. The script was run and the results checked by me.

A walk through one AshStateMachine action, from the obvious version to ones that are safe under concurrency. locked_transition.exs (next to this file) runs every version against PostgreSQL. The results below are from Ash 3.34.6 and Ash main (291f5fc, 2026-10-09), with AshPostgres 2.14.5 and AshStateMachine 0.2.13; main includes the ash#3008 fix.

The scenario

An order is :open until its payment succeeds. The payment provider's webhook then calls confirm_payment, which must:

Performance comparison

Comparing main (ash-project/ash_sqlite@f018e3c) against this branch (wtsnz/ash_sqlite@27c0923) using the actual AshSqlite query path: build with Ash.Query.data_layer_query/1, render with Ecto.Adapters.SQL.to_sql/3, then execute with Repo.all/1. The fixture used 20k posts; local SQLite reports MAX_VARIABLE_NUMBER=32766.

SQL shape at 900 list values:

branch	SQL shape	SQL bytes	OR terms	IN terms	bind params
`main`	OR chain	19,882	899	0	901
this branch	compact IN	1,905	0	1	901

Credo Installation Guide

Practical baseline for installing Credo in Elixir apps and umbrella apps.

Goals:

explicit lint policy
predictable upgrades
low-noise default setup
optional stricter checks later

A dump of the SwiftUI.framework binary for the iOS simulator (as of Xcode 12.0 beta 2) using the swift-reflection-dump tool.

Note: I used a Swift 5.3 compiler build from a few weeks ago that I had laying around. Because of ABI stability, I don't think the swift-reflection-dump version has to match the compiler version that was used to build the binary, but I'm not 100% sure.

Introducing Bitcoin
ryan@ryanxcharles.com
Nov 19, 2021
https://www.ryanxcharles.com/content/

Introduction

I’ve been involved in Bitcoin since May 13, 2011 when I read an article about Bitcoin on Hacker News. It struck me that Bitcoin had the potential to be the foundation of a new global industry like the internet, but with money instead of communications. I was hooked right away and spent weeks researching it.

	# Project Policy

	This policy provides a single, authoritative, and machine-readable source of truth for AI coding agents and humans, ensuring that all work is governed by clear, unambiguous rules and workflows. It aims to eliminate ambiguity, reduce supervision needs, and facilitate automation while maintaining accountability and compliance with best practices.

	# 1. Introduction

	> Rationale: Sets the context, actors, and compliance requirements for the policy, ensuring all participants understand their roles and responsibilities.

	## 1.1 Actors

	import SwiftUI

	extension CollectionView {
	typealias UIKitCollectionView = CollectionViewWithDataSource<SectionIdentifierType, ItemIdentifierType>
	typealias DataSource = UICollectionViewDiffableDataSource<SectionIdentifierType, ItemIdentifierType>
	typealias Snapshot = NSDiffableDataSourceSnapshot<SectionIdentifierType, ItemIdentifierType>
	typealias UpdateCompletion = () -> Void
	}

	struct CollectionView<SectionIdentifierType, ItemIdentifierType>

	官方视频地址：https://developer.apple.com/videos/wwdc/2014/

	权当留个念想，选择下面的链接，然后复制，在迅雷中新建下载，粘贴即可。支持多文件下载。

	对应的字幕可以查看 https://github.com/qiaoxueshi/WWDC_2014_Video_Subtitle

	http://devstreaming.apple.com/videos/wwdc/2014/704xx7dmqd5m9l4/704/704_sd_building_apps_for_enterprise_and_education.mov?dl=1

	http://devstreaming.apple.com/videos/wwdc/2014/236xxwk3fv82sx2/236/236_sd_building_interruptible_and_responsive_interactions.mov?dl=1

	import SwiftUI

	struct ContentView: View {

	@State var now = Date()
	@State var showWindow = false
	@State var text: String = ""

	let timer = Timer.publish(every: 1, on: .current, in: .common).autoconnect()

	import Combine
	import SwiftUI

	class RemoteImageLoader: ObservableObject {

	@Published var data: Data = Data()

	init(imageURL: URL) {
	URLSession.shared.dataTask(with: imageURL) { data, response, error in
	guard let data = data else { return }