parsonsmatt

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE UndecidableInstances #-}
{-# LANGUAGE GADTs #-}

{-# OPTIONS_GHC -Wall #-}

module Main where

dcastro

import shapeless._, record._
import io.circe._
import io.circe.syntax._
import io.circe.generic.encoding._

case class Person(name: String, age: Int)

object Person {
  implicit val encodePerson: Encoder[Person] =
    ReprObjectEncoder.deriveReprObjectEncoder.contramap { person =>

non

introduction

ScalaCheck 1.14.0 was just released with support for deterministic testing using seeds. Some folks have asked for examples, so I wanted to produce a Gist to help people use this feature.

simple example

These examples will assume the following imports:

schmich

Programming Media Keys on the Ducky One 2 Skyline

To use media keys on the Ducky One 2 Skyline, you must record a macro to bind the media function to a hotkey combination, i.e. Fn plus some key.

Example

Important: In the instructions below, "Press X+Y+Z" means press and hold key X, press and hold key Y, press and hold key Z in that order, and then release all three.

As an example, to bind Fn+PgUp to the play/pause media function:

kritzcreek

Kinds

In PureScript there are types of different kinds. Kinds are types for types. For example Int has kind Type, and we write it as Int :: Type. You can ask for the kind of a type in purs psci

> :k Int
Type

Type constructors take types to other types. For example Array (which still needs another type to form a type a value could have, like Array Int):

junegunn

# GIT heart FZF
# -------------

is_in_git_repo() {
  git rev-parse HEAD > /dev/null 2>&1
}

fzf-down() {
  fzf --height 50% --min-height 20 --border --bind ctrl-/:toggle-preview "$@"
}

developmentalmadness

package com.dvMENTALmadness

import akka.actor.ActorSystem
import akka.stream.ActorMaterializer
import akka.http.scaladsl.Http
import akka.http.scaladsl.model._
import scala.concurrent.Await
import scala.concurrent.ExecutionContext.Implicits.global
import scala.concurrent.duration._

estliberitas

'use strict';

// Usage
//   node check-markdown-links.js path/to/markdown/file.md

// What it does:
// - Warns when `[ref][]` or `[title][ref]` style links don't have references defined on a page
// - Warns when `[ref]: URL` reference is not used anywhere
// - Warns when two `[ref]: URL` references point to same `URL`
// - Warns when `[ref]: URL` reference is defined in non-lexical order

pchiusano

This is material to go along with a 2014 Boston Haskell talk.

We are going to look at a series of type signatures in Haskell and explore how parametricity (or lack thereof) lets us constrain what a function is allowed to do.

Let's start with a decidedly non-generic function signature. What are the possible implementations of this function which typecheck?

wrangle :: Int -> Int

rgs

Falsehoods programmers believe about prices

1. You can store a price in a floating point variable.
2. All currencies are subdivided in 1/100th units (like US dollar/cents, euro/eurocents etc.).
3. All currencies are subdivided in decimal units (like dinar/fils)
4. All currencies currently in circulation are subdivided in decimal units. (to exclude shillings, pennies) (counter-example: MGA)
5. All currencies are subdivided. (counter-examples: KRW, COP, JPY... Or subdivisions can be deprecated.)
6. Prices can't have more precision than the smaller sub-unit of the currency. (e.g. gas prices)
7. For any currency you can have a price of 1. (ZWL)
8. Every country has its own currency. (EUR is the best example, but also Franc CFA, etc.)