Rodrigo Navarro reu

Introduction

I was recently asked to explain why I felt disappointed by Haskell, as a language. And, well. Crucified for crucified, I might as well criticise Haskell publicly.

First though, I need to make it explicit that I claim no particular skill with the language - I will in fact vehemently (and convincingly!) argue that I'm a terrible Haskell programmer. And what I'm about to explain is not meant as The Truth, but my current understanding, potentially flawed, incomplete, or flat out incorrect. I welcome any attempt at proving me wrong, because when I dislike something that so many clever people worship, it's usually because I missed an important detail.

Another important point is that this is not meant to convey the idea that Haskell is a bad language. I do feel, however, that the vocal, and sometimes aggressive, reverence in which it's held might lead people to have unreasonable expectations. It certainly was my case, and the reason I'm writing this.

Type classes

I love the concept of type class

Emulating the elegance of JavaScript's `new Array` in Haskell

What does new Array(x) do? Trick question. It does different things depending on whether x is an integer or something else.

I wanted to replicate this elegant functionality in Haskell: behold.

Generating collections of random numbers in PureScript

A problem that I've seen beginners run into in Haskell or PureScript a couple of times now is how to generate a List of random numbers. It's a common requirement for little games (which make for great first projects) to generate these, and it definitely seems to be a stumbling block.

Why are random numbers hard?

Randomness is considered a side effect in purely functional languages, which means that to generate them you usually need access to Eff/IO, which in turn means we need to deal with Monads. And while generating a single random number is usually pretty easy with do-notation, the typical intuition beginners have built when going from single values to a collection is to use map, but that fails.

Type-Directed-Search to the rescue

Exporting your 2FA tokens from Authy to transfer them into another 2FA application

IMPORTANT - Update regarding deprecation of Authy desktop apps

Past August 2024, Authy stopped supported the desktop version of their apps:
See Authy is shutting down its desktop app | The 2FA app Authy will only be available on Android and iOS starting in August for details.

And indeed, after a while, Authy changed something in their backend which now prevents the old desktop app from logging in. If you are already logged in, then you are in luck, and you can follow the instructions below to export your tokens.

If you are not logged in anymore, but can find a backup of the necessary files, then restore those files, and re-install Authy 2.2.3 following the instructions below, and it should work as expected.

	import os
	import math
	import strutils
	import strformat

	import nimgl/opengl
	import nimgl/glfw
	import nimgl/imgui
	import nimgl/imgui/impl_opengl
	import nimgl/imgui/impl_glfw

	package com.jivimberg.sqs.published

	import kotlinx.coroutines.CancellationException
	import kotlinx.coroutines.CoroutineScope
	import kotlinx.coroutines.isActive
	import kotlinx.coroutines.yield
	import java.lang.Thread.currentThread

	suspend fun CoroutineScope.repeatUntilCancelled(block: suspend () -> Unit) {
	while (isActive) {

	{-# LANGUAGE DataKinds #-}
	{-# LANGUAGE FlexibleInstances #-}
	{-# LANGUAGE LambdaCase #-}
	{-# LANGUAGE FunctionalDependencies #-}
	{-# LANGUAGE TypeFamilies #-}
	{-# LANGUAGE TypeOperators #-}
	{-# LANGUAGE UndecidableInstances #-}
	module Main where

	import Data.Kind

	use std::fmt;

	enum FizzBuzzOr {
	Fizzbuzz(&'static str),
	Or(i32)
	}

	impl fmt::Display for FizzBuzzOr {
	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
	use FizzBuzzOr::*;

	# Backup files
	#https://explainshell.com/explain?cmd=rsync+-azuv+--delete+--progress+--exclude+%27node_modules%27

	rsync -auvhp --delete --exclude=node_modules [source] [destination]

	# Remove all node_modules folders
	# https://explainshell.com/explain?cmd=find+.+-name+%22node_modules%22+-type+d+-prune+-exec+rm+-rf+%27%7B%7D%27+%2B

	find . -name "node_modules" -type d -prune -exec rm -rf '{}' +

	{-# LANGUAGE OverloadedStrings #-}
	{-# OPTIONS_GHC -Wall #-}

	-- Set your font to a monospace font which makes this character the same as the line-height: │
	--
	-- Otherwise, you'll see an ugly gap between connected lines if the
	-- line-height of the font is high.
	--
	-- Example fonts:
	--