const app = {
lines: document.getElementById('lines'),
textbox: createTextbox(),
lineTemplate: createLineTemplate(),
}

const socket = connect(
`ws://${location.host}/app`,
{

initial({ lines, uuid, charLimit }) {
app.uuid = uuid
app.charLimit = charLimit
lines.forEach(addLine)
},

added(line) {
addLine(line)
},

removed(i) {
app.lines.children[i].remove()
},

server.onclose = (ws) => {
if (ws.line) {
const i = lines.indexOf(ws.line)
lines.splice(i, 1)
server.sendToAll({ removed: i })
}
}

server.commands = {

begin(ws) {
const line = {
hash: ws.hash,
uuid: ws.uuid,
text: '',
}

ws.line = line
lines.push(line)
server.sendToAll({ added: line })
},

run() {
console.log(`Running on port ${this.port}`)

this.wss = new WebSocket.Server({
port: this.port,
verifyClient: this.verify.bind(this)
})

setInterval(
this.prune.bind(this),
this.pruneInterval * 1000
)

this.wss.on(
'connection',
this.connection.bind(this)
)
}

Steven Degutis

Full-stack software developer for hire

First thoughts on Haskell

February 9, 2015 — 2 years ago

I spent the past few weeks using the evening and weekend to learn Haskell and research how I could use it to build a web app. Here's the most interesting points I found:

Compared to Clojure

  1. Rich borrowed almost all of Clojure's standard library from Haskell.
  2. Destructuring in Clojure also looks like it came directly from Haskell.
  3. Haskell's pattern matching is so much more useful than Clojure's core.match library.
  4. Haskell's sum types are really indispensable, I really wish Clojure had them.
  5. Static typing acts like free unit tests!
  6. Type inference means you almost never have to specify a type, so it feels as limber as dynamic typing.

Neat features

  1. You can use the $ operator to avoid parentheses. So foo quux (bar baz) can become foo quux $ bar baz.
  2. All functions are curried, so there's no need for Clojure's partial function.
  3. You can make your own operators, with their own precedence and associativity.
  4. Type classes are great for polymorphism, and can also define operators (like Eq and Ord do).

Uses for monads

  1. They make sequential operations much less ugly while working in a purely-functional language.
  2. They can be used to separate interface from implementation.
  3. They make error propagation much simpler. In almost all cases, you can use the Either or Maybe monads to replace exceptions.
  4. A lot of what they call EDSLs (like Clay, Lucid, Scotty, etc.) are made using monads.

The bad

  1. I love Haskell's syntax in theory, but real-world code is kind of hard for me to read. Maybe it just takes time like it did with Clojure.
  2. We have to pay attention to operator precedence once again.
  3. The tooling around Haskell isn't as good as in the Clojure ecosystem, but it's not that far off.
  4. The "do" syntactic sugar for chaining monads can trick you into thinking you're writing imperative code. This confused me at first.

The ugly

  1. Records (like defrecord) can't use a field name that's already been used within another record in the same namespace.
  2. Monads still confuse me a lot, even though I think I understand them.
  3. There's such a thing as "Monad Transformers" which sound even scarier than Monads to me. I've yet to even look into them.
  4. Compiling a Haskell project is about as slow as compiling a Clojure project.
  5. I really don't like lazy IO. But it's not related to non-strict evaluation, so it's very much an opt-in feature that I just wouldn't use.

Some interesting libraries

  1. Clay: library to generate CSS, like Garden.
  2. Lucid: library to generate HTML, like Hiccup.
  3. Hspec: RSpec clone.
  4. Scotty: just like Compojure, built on top of WAI, the Haskell equivalent to Ring.
  5. Aeson: JSON library, but serves a similar purpose as Prismatic's Schema.

There are also a few Haskell-to-JavaScript compilers, but the situation's still in flux. Some people want a full runtime, others want none. Some want lazy ("non-strict") evaluation, some want normal evaluation so that it emits more readable JavaScript.

Anyway, just some thoughts on Haskell. It looks really cool, but I'm still undecided on whether I want to actually write a real-world app in Haskell.

About me

My name is Steven Degutis, and I've been writing software professionally for almost a decade. During that time, I've written many apps and websites, quite a few techical articles, and kept up-to-date with the rapidly evolving software industry.

If you have software needs for web, mobile, or desktop, and are looking for a seasoned software professional, please reach out to me at sbdegutis@gmail.com to set up a phone call.

Work Experience

  • Self-employed – present
  • Clean Coders – 5 years
  • 8th Light – 2 years
  • Big Nerd Ranch – 1 year
  • Self-employed - 1 year

Platforms

  • Web: full-stack
  • iOS (UIKit)
  • macOS (Cocoa)
  • REST APIs
  • AWS / EC2 / ELB

Languages

  • JavaScript
  • HTML5 / CSS
  • Swift
  • Objective-C
  • Clojure

Frameworks

  • Node.js
  • Express.js
  • React
  • Vue.js
  • Electron

Technical articles

Over the past decade, I've written a total of 169 technical articles on various programming languages, frameworks, best practices, and my own projects, as I kept up-to-date and active in the software industry.

Subscribe via RSS / Atom.

Chronological

Portfolio

Here are some of the projects I'm most proud of. They were created using a variety of technologies, running on several different platforms and OSes. They're all finished products, and many of them are open source.

CleanCoders.com

Website - Online Video Store

I wrote this web store for Robert "Uncle Bob" Martin, using Clojure for the back-end, and JavaScript for the front-end. Over the course of 5 years, I took the site from a simple three-page website to a full enterprise-ready business solution, with nearly 100% test coverage.

  • Clojure
  • Datomic
  • jQuery / D3.js
  • JavaScript
  • ClojureScript

Docks

macOS app - Dock Utility

I made Docks in 2009 for users who wanted to swap out icons in their Dock with a single click. Its unique functionality and design aesthetic attracted the attention of Apple, Engadget, MacWorld, and led to an acquisition of my start-up by Big Nerd Ranch.

  • Apple.com Staff Pick
  • MacWorld 4/5 Rating
  • MacWorld Gem of the Year
  • Featured on Engadget.com

Leviathan

macOS app - Clojure IDE

Source Code

While working on CleanCoders.com, a website written completely in Clojure, I increased my productivity by building a custom IDE for macOS designed specifically for Clojure projects.

  • Objective-C
  • Clojure
  • C / C++
  • Cocoa
  • Themeable

Zephyros

macOS app - Hackable Automation

Source Code

This began as an experiment to see how many languages I could use to script a custom macOS window manager using our custom TCP protocol. Eventually it had bindings for Clojure, Ruby, Python, Go, JavaScript, CoffeeScript, Node.js, Chicken Sceme, and Racket, as well as other community additions.

  • TCP / Unix sockets
  • Custom protocol
  • Highly Scriptable
  • 10+ language bindings
  • Open source community

Bubble Maker

iOS app - Bubble simulator

This toy was made in a weekend to entertain my 1 year old daughter. It lets you create bubbles with your fingers, which then simulate physics by bumping into each other and falling.

  • SpirteKit
  • Custom art
  • Physics simulation
  • iOS
  • tvOS

Quick List

iOS app - Todo list app

When I couldn't find an app in the App Store that let me make very simple lists extremely quickly, I made one myself. I use it almost every day to organize and track my activities.

  • In-app purchases
  • Custom UI / UX
  • Social media
  • App Store artwork
  • Spring animations

sdegutis.com

Website - Personal Portfolio

Source Code

This very site itself was written from scratch in about a day. It uses best practices for modern responsive web design, and a custom build phase to compile the sources into a single HTML file.

  • Node.js
  • Pug / Jade
  • LessCSS
  • HTML5
  • WebSockets

2048

Java app - Game

Source Code

The game 2048 (created by Gabriele Cirulli) is so fun that my kids wanted their own copy. So I wrote this version in Java 8, using JavaFx for attractive graphics and silky smooth animations.

  • Java 8
  • JavaFx
  • Modular code
  • Customizable
  • Animations

Mjolnir

macOS app - Window Manager

Source Code

I created this app to increase my productivity by letting me move windows around in macOS using keyboard shortcuts. It grew into a community-driven highly extensible app, using Lua for its plugin system.

  • Objective-C
  • Embedded Lua
  • Plugin system
  • Fully documented
  • 5,000 GitHub stars

AffluentConfidante.com

Website - Social Network

Implementing this elite social network gave me experience integrating both Apple Pay and credit card payments (via Stripe.com) seamlessly into web apps, for a frictionless and pain-free payment experience.

  • Clojure
  • Elastic Beanstalk
  • PostgreSQL
  • Stripe.com
  • Apple Pay

HyperChat

Website - Live Chatroom

Source Code

This isn't just any chatroom. In this web app, you can see what everyone is typing while they type it. I made this in order to scratch my itch for making real-time apps and games, and learned how to use WebSockets in the process.

  • JavaScript
  • WebSockets
  • Node.js
  • Vue.js
  • CSS

Bahamut

macOS app - Music Player

Source Code

As iTunes went through many user interface changes, I wanted an app that was consistent, intuitive, and easy to use. So I created Bahamut, a minimal music player for macOS with a custom user interface.

  • Objective-C
  • Custom UI
  • Cocoa
  • Core Data
  • AVFoundation

Chatter

macOS app - Chat (IRC) Client

Source Code

This was written in 2009, before the time of Slack, when IRC was the main way for programmers to get short-term assistance from each other. Its purpose was to be a beautiful app with an emphasis on simplicity and usability over technical power.

  • Async networking
  • Core Animation
  • Core Text
  • IRC Protocol
  • UI Design

AppGrid

macOS app - Window Manager

Source Code

This is an app I actually use every single day. It lets you move windows with global keyboard shortcuts. Since it uses Vim-like key bindings, it should feel pretty natural to any programmer. There's no configuration needed; it Just Works™.

  • Minimalist UI
  • Simple UI
  • Vim-like Hotkeys
  • Global Hotkeys
  • Zero-configuration

Hydra

macOS app - Lua window manager

Source Code

As an evolution of Phoenix, Hydra was my first attempt at embedding a full Lua virtual machine into an Objective-C app, to make a lightweight and efficient window manager that focused on speed, low memory usage, low CPU usage, and overall being gentle on laptop batteries.

  • Embedded Lua
  • Generated docs
  • Lightweight
  • Memory efficient
  • CPU efficient

Phoenix

macOS app - JavaScript window manager

Source Code

As an evolution of Zephyros, Phoenix was my attempt to use Cocoa's native JavaScript bindings to make a more lightweight and efficient window manager, that focused on speed, low memory usage, low CPU usage, and overall being gentle on laptop batteries.

  • JavaScriptCore
  • JavaScript API
  • Lightweight
  • Memory efficient
  • CPU efficient

Smaller projects

These may be tiny, but they're interesting technical feats.

Lua4SwiftSwift framework for embedding Lua with a native Swift API.
chooseCommand line fuzzy-matching tool for macOS that uses a GUI
musicCommand line music daemon for macOS that only speaks JSON
hectoCommand line text editor with an embedded Lua plugin system
ZephSharpWindow manager for Windows using Clojure for scripting
managementMinimalist EC2 configuration & deployment tool in Ruby.
go.assertAssertion helper package for writing tests in Go.
go.shattrGo library for printing shell-attributed strings to stdout.
OCDSpec2Objective-C based testing framework with Xcode integration.