austintaylor

type Precedence = Int
data Associativity = AssocL | AssocR
data Token = Operand Int | Operator String (Int -> Int -> Int) Associativity Precedence | ParenL | ParenR

instance Show Token where
  show (Operator s _ _ _) = s
  show (Operand x)        = show x
  show ParenL             = "("
  show ParenR             = ")"

Fristi

{-# LANGUAGE TypeFamilies #-}

import Data.Function (on)
import Control.Applicative

data EventData e = EventData {
    eventId :: Int,
    body :: Event e
}

garybernhardt

(Chapters marked with * are already written. This gets reorganized constantly
and 10 or so written chapters that I'm on the fence about aren't listed.)

Programmer Epistemology
  * Dispersed Cost vs. Reduced Cost
  * Verificationist Fallacy
  * Mistake Metastasis
  The Overton Window
  Epicycles All The Way Down
  The Hyperspace Gates Were Just There

paf31

Introduction

At DICOM Grid, we recently made the decision to use Haskell for some of our newer projects, mostly small, independent web services. This isn't the first time I've had the opportunity to use Haskell at work - I had previously used Haskell to write tools to automate some processes like generation of documentation for TypeScript code - but this is the first time we will be deploying Haskell code into production.

Over the past few months, I have been working on two Haskell services:

• A reimplementation of an existing socket.io service, previously written for NodeJS using TypeScript.
• A new service, which would interact with third-party components using standard data formats from the medical industry.

I will write here mostly about the first project, since it is a self-contained project which provides a good example of the power of Haskell. Moreover, the proces

sebmarkbage

import { Component } from "React";

export var Enhance = ComposedComponent => class extends Component {
  constructor() {
    this.state = { data: null };
  }
  componentDidMount() {
    this.setState({ data: 'Hello' });
  }
  render() {

jamestalmage

Why

Doing require extensions correctly is essential, because:

1. Users should be able to install multiple extensions in succession, and have them work together.
2. Coverage tools like nyc need it to reliably supply coverage information that takes into account sourcemaps from upstream transforms.
3. Because non-standard, un-predictable behavior causes hard to solve bugs, and major headaches for project maintainers.

What is a require extension anyways?

luisherranz

I'd got rid of action types and I'd have only actions (action creators). No strings, the function (reference) is used later for comparisons.

export const addTodo = (id, title) => ({ id, title });
export const removeTodo = id => ({ id });
actions({ addTodo, removeTodo }); // Connect it to actions.addTodo & actions.removeTodo.

That's it. They define what your app can do.