elfenlaid

// This gist demonstrates how you can implement versioning for a Codable struct to support loading
// old serialized data after changing the structure. Notable features of this solution:
//
// * No need to make new properties optional, or to perform post-processing on the struct after
//   loading in ordeer to populate missing values
// * No need to change the call site - from the outside this struct behaves just the same
//   as if we had implemented codable directly in the normal way.
// * Versioning can be applied individually to parents or leaves in a larger tree of
//   structs without affecting the other elements
// * This approach will work even if the original struct was not designed with versioning in mind

elfenlaid

/*
 * This is an example provided by Facebook are for non-commercial testing and
 * evaluation purposes only.
 *
 * Facebook reserves all rights not expressly granted.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON INFRINGEMENT. IN NO EVENT SHALL
 * FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN

elfenlaid

A composable pattern for pure state machines with effects

State machines are everywhere in interactive systems, but they're rarely defined clearly and explicitly. Given some big blob of code including implicit state machines, which transitions are possible and under what conditions? What effects take place on what transitions?

There are existing design patterns for state machines, but all the patterns I've seen complect side effects with the structure of the state machine itself. Instances of these patterns are difficult to test without mocking, and they end up with more dependencies. Worse, the classic patterns compose poorly: hierarchical state machines are typically not straightforward extensions. The functional programming world has solutions, but they don't transpose neatly enough to be broadly usable in mainstream languages.

Here I present a composable pattern for pure state machiness with effects,

elfenlaid

// A heterogeneous dictionary with strong types in Swift, https://oleb.net/2022/heterogeneous-dictionary/
// Ole Begemann, April 2022

/// A key in a `HeterogeneousDictionary`.
public protocol HeterogeneousDictionaryKey {
  /// The "namespace" the key belongs to. Every `HeterogeneousDictionary` has its associated domain,
  /// and only keys belonging to that domain can be stored in the dictionary.
  associatedtype Domain
  /// The type of the values that can be stored under this key in the dictionary.
  associatedtype Value

elfenlaid

// Run any SwiftUI view as a Mac app.

import Cocoa
import SwiftUI

NSApplication.shared.run {
    VStack {
        Text("Hello, World")
        	.padding()
            .background(Capsule().fill(Color.blue))

elfenlaid

git config --global alias.trim '!f() { git branch | grep -v "\*" | xargs -n 1 git branch -D; }; f'

elfenlaid

Xcodebuild flag reference for CI:

Required flags:

-project OR -workspace

What xcode project/workspace file we're using. If you specify a project on the command-line and that project has an associated workspace, the project is still aware of its existence within the workspace. As an example, worspace level schemes will be available to xcodebuild even if you specify a project on the command line.

-scheme

Specify the scheme to use for build. Schemes specify multiple build/test targets along with environment args and command line parameters. Schemes must be marked "shared" in the xcode UI in order to be available to xcodebuild. For any particular build/test action there is a default configuration when you use a scheme from the Xcode UI.

elfenlaid

Xcodebuild flag reference for CI:

Required flags:

-project OR -workspace

What xcode project/workspace file we're using. If you specify a project on the command-line and that project has an associated workspace, the project is still aware of its existence within the workspace. As an example, worspace level schemes will be available to xcodebuild even if you specify a project on the command line.

-scheme

Specify the scheme to use for build. Schemes specify multiple build/test targets along with environment args and command line parameters. Schemes must be marked "shared" in the xcode UI in order to be available to xcodebuild. For any particular build/test action there is a default configuration when you use a scheme from the Xcode UI.

elfenlaid

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RankNTypes #-}
module Bencoding where

import Control.Applicative
import Crypto.Hash.SHA1
import Data.Attoparsec.ByteString.Char8 (Parser)
import qualified Data.Attoparsec.ByteString.Char8 as P
import Data.ByteString as B
import Data.ByteString.Char8 as BC

elfenlaid

######################
# Options
######################

REVEAL_ARCHIVE_IN_FINDER=false

FRAMEWORK_NAME="${PROJECT_NAME}"

SIMULATOR_LIBRARY_PATH="${BUILD_DIR}/${CONFIGURATION}-iphonesimulator/${FRAMEWORK_NAME}.framework"