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Romain Ruetschi romac

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romac / README.md
Last active June 19, 2020 10:20
Switch between iTerm profiles based on the active macOS theme
@scottmatthewman
scottmatthewman / AdaptsToSoftwareKeyboard.swift
Last active April 19, 2024 12:56
An example of using Combine to automatically adapt a SwiftUI scrollable view to accommodate an iOS onscreen keyboard
import SwiftUI
import Combine
struct AdaptsToSoftwareKeyboard: ViewModifier {
@State var currentHeight: CGFloat = 0
func body(content: Content) -> some View {
content
.padding(.bottom, currentHeight)
.edgesIgnoringSafeArea(.bottom)
@mosen
mosen / Share.swift
Created March 6, 2018 04:55
Convenient swift-like wrapper over NetFS smb mounting
import Foundation
import NetFS
enum ShareMountError: Error {
case InvalidURL
case MountpointInaccessible
case InvalidMountOptions
}
@non
non / laws.md
Last active February 20, 2022 00:26
I feel like conversations around laws and lawfulness in Scala are often not productive, due to a lack of rigor involved. I wanted to try to be as clear and specific as possible about my views of lawful (and unlawful) behavior, and what I consider a correct and rigorous way to think about laws (and their limits) in Scala.

Laws

A law is a group of two or more expressions which are required to be the same. The expressions will usually involve one or more typed holes ("inputs") which vary.

Some examples:

x.map(id) === x
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DefaultSignatures #-}
{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE ScopedTypeVariables #-}

Revisiting Tagless Final Interpreters

Tageless Final interpreters are an alternative to the traditional Algebraic Data Type (and generalized ADT) based implementation of the interpreter pattern. This document presents the Tageless Final approach with Scala, and shows how Dotty with it's recently added implicits functions makes the approach even more appealing. All examples are direct translations of their Haskell version presented in the Typed Tagless Final Interpreters: Lecture Notes (section 2).

The interpreter pattern has recently received a lot of attention in the Scala community. A lot of efforts have been invested in trying to address the biggest shortcomings of ADT/GADT based solutions: extensibility. One can first look at cats' Inject typeclass for an implementation of [Data Type à la Carte](http://www.cs.ru.nl/~W.Swierstra/Publications/DataTypesA

@phadej
phadej / DepProb.hs
Last active May 12, 2018 21:16
This file is my attempt to clarify and formalise my own thoughts about dependency resolution problem.
{-# LANGUAGE DeriveFoldable #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE FunctionalDependencies #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE UndecidableInstances #-}
-- | This file is my attempt to clarify and formalise my own thoughts about
-- dependency resolution problem.
@TerrorJack
TerrorJack / Pool.hs
Last active June 13, 2016 19:09
A simple thread pool. You can dispatch IO actions to the pool for execution.
import Control.Concurrent.Async
import Control.Concurrent.STM.TBChan
import Control.Exception
import Control.Monad
import Data.Foldable
import Data.Vector as V
import GHC.Conc
data PoolConfig = PoolConfig {
threadCount :: Int,
@rahulmutt
rahulmutt / Interacting with Java in GHCVM.md
Last active November 22, 2017 22:27
Documents how the Java Foreign Function Interface will look in GHCVM, a Haskell to JVM compiler.

Explaining Miles's Magic

Miles Sabin recently opened a pull request fixing the infamous SI-2712. First off, this is remarkable and, if merged, will make everyone's life enormously easier. This is a bug that a lot of people hit often without even realizing it, and they just assume that either they did something wrong or the compiler is broken in some weird way. It is especially common for users of scalaz or cats.

But that's not what I wanted to write about. What I want to write about is the exact semantics of Miles's fix, because it does impose some very specific assumptions about the way that type constructors work, and understanding those assumptions is the key to getting the most of it his fix.

For starters, here is the sort of thing that SI-2712 affects:

def foo[F[_], A](fa: F[A]): String = fa.toString