inamiy

-- Solving Fix / Mu / Nu exercise in
-- https://stackoverflow.com/questions/45580858/what-is-the-difference-between-fix-mu-and-nu-in-ed-kmetts-recursion-scheme-pac

{-# LANGUAGE RankNTypes, GADTs #-}

----------------------------------------
-- Fix / Mu / Nu

newtype Fix f = Fix { unFix :: f (Fix f) }

caadar

#!/run/current-system/sw/bin/bash

SCANNED="$1"
AFFIX="${1##*.}"
DATESTAMP=$(date '+%Y%m%d')
TIMESTAMP=$(date '+%H%M%S')

mv "${SCANNED}" "/home/user/${DATESTAMP}..scan-${TIMESTAMP}.${AFFIX}"

nh2

#!/usr/bin/env bash

# Installs NixOS on a Hetzner server, wiping the server.
#
# This is for a specific server configuration; adjust where needed.
#
# Prerequisites:
#   * Update the script to adjust SSH pubkeys, hostname, NixOS version etc.
#
# Usage:

gelisam

-- Solving a dynamic programming in many ways, including using existing
-- recursion schemes and by defining new ones. The problem of solving this
-- particular problem using recursion schemes was posed by Sandy Maguire.
{-# LANGUAGE FlexibleContexts, RankNTypes, TypeApplications, TypeFamilies, ScopedTypeVariables #-}
{-# OPTIONS -Wno-orphans #-}
module Dyna where
import Test.DocTest

import Data.Functor.Foldable (Base, Fix, Recursive(project), Corecursive(embed, ana), hylo, cataA)

timstott

{ config, lib, pkgs, ... }: {
  config = {
    boot.kernelModules = [];
    networking = {
      extraHosts = ''
          xxx.xxx.xxx.xxx bob-remote bob-remote-unencrypted
          127.0.0.1 bob-remote-encrypted
      '';
      firewall.trustedInterfaces = [];
      publicIPv4 = "xxx.xxx.xxx.xxx";

dwhitney

1. create-react-native-app purescript-app; cd purescript-app

2. pulp init --force

3. pulp build

4. src/Main.js

var React = require("react");
var RN = require("react-native");

exports.text = function(props){

parsonsmatt

The question of "How do I design my application in Haskell?" comes up a lot. There's a bunch of perspectives and choices, so it makes sense that it's difficult to choose just one. Do I use plain monad transformers, mtl, just pass the parameters manually and use IO for everything, the ReaderT design pattern, free monads, freer monads, some other kind of algebraic effect system?!

The answer is: why not both/all?

Lately, I've been centering on a n application design architecture with roughly three layers:

Layer 1:

newtype AppT m a = AppT { unAppT :: ReaderT YourStuff m a } deriving ............ The ReaderT Design Pattern, essentially. This is what everything gets boiled down to, and what everything eventually gets interpreted in. This type is the backbone of your app. For some components, you carry around some info/state (consider [MonadMetrics](https://hackage

nektro

/* Safari and Edge polyfill for createImageBitmap
 * https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/createImageBitmap
 */
if (!('createImageBitmap' in window)) {
    window.createImageBitmap = async function(blob) {
        return new Promise((resolve,reject) => {
            let img = document.createElement('img');
            img.addEventListener('load', function() {
                resolve(this);
            });

kritzcreek

"Is Haskell a good first programming language?"

This question was asked at the recent HaskellX conference, with both practicioners as well as teachers being present. I won't reiterate everything that was said, and instead link to a recording of the podium discussion (https://skillsmatter.com/skillscasts/10952-park-bench-panel-session-with-haskellx-experts).

One particular argument, that I've heard come up multiple times now, is that teachers are complaining about the length function being polymorphic. Apparently length :: forall a. Foldable f => f a -> Int is hard to grasp/understand/accept for a new-comer. The solutions proposed to solve this problem are to:

1. Return length to its non-Foldable type
2. Use a custom Prelude to teach beginners

Drawbacks for 1 include that practicioners like the fact that length works for all kinds of data structures, and don't want that taken away from them. The primary problem with solution 2 is that students can't go and use their aquired knowledge to work on Open

i-am-tom

module MapRecordWithComments where

-- | Type-level Tomfoolery. A million thankyous to @kcsongor and his
-- | unparallelled patience with me while I try to figure this stuff
-- | out.

import Prelude (($), (+), (<>), discard, show)

import Control.Monad.Eff (Eff)
import Control.Monad.Eff.Console (CONSOLE, log)