PurelyFunctional.tv Newsletter 250: Lean, Creole Cuisine, Types

Issue 250 - November 06, 2017

Hi Clojurfarians,

Can you believe that this is the 250th issue? To celebrate, here's a coupon code for 50% off any and all courses on PurelyFunctional.tv.


I'm not sure how long I'm going to keep the coupon active, but it's active now. Thank you for being a part of this adventure.

In other news, RubyConf is coming to New Orleans very soon. I won't be attending, but I will be in town. If you are attending, let me know and we can meet. You may also want the Food Guide (linked below).

Please enjoy the issue.

Rock on!

PS Want to get this in your email? Subscribe!

Food Guide to New Orleans for Clojure SYNC

New Orleans is home to Creole cuisine. It's a set of dishes and cooking techniques that people cook at home and you also find outside of the home at restaurants and gatherings. Dishes like red beans and rice, gumbo, and crawfish étouffée. When you come to Clojure SYNC, you may find yourself browsing through the menu of a local restaurant, scratching your head about what you'll get if you order jambalaya. I made this guide to help you out.

There are still tickets available. Remember that Clojure/West will be merged with the Conj next year, so there's no other US Clojure conferences around that time.

The Cost Center Trap

An excellent essay by Mary Poppendieck about treating IT as a cost center instead of a profit center. She has been a pioneer in Agile and Lean software methods for many years. I always look to her work for guidance.


Zach Oakes is at it again! This time, he's built a tool to build full-stack Clojure/ClojureScript applications. It is totally self-contained. You install the package for your OS (Mac, Windows, Linux) and it needs nothing else to run! Be sure to watch the screencast to understand more about how it works.

On Types and Intent

More discussion stemming from Rich Hickey's latest talk at the Conj. This is a great, balanced and measured take by Jean-Louis Giordano comparing Haskell with Clojure.


I will be speaking at LambdaUp in Prague in December. Are you going? There are some cool speakers and the tickets are not expensive. Give it a shot!

Expo ClojureScript Template

Sean Tempesta has created a template for React Native apps using Expo. With Expo, you don't need XCode or Android Studio to develop your app.

Deliver software faster by managing work in progress, not by adding overtime

Another Lean idea is to keep work in progress to a minimum. This article by Matt Weiden goes into lots of detail about policy changes at SoundCloud that resulted in better time to delivery.

Understanding Re-frame

I've been recording this course, which aims to be a comprehensive tour of everything in Re-frame. Right now, I'm focused on Reagent's Hicc up. You'll find lessons on React's Event system; using inline style attributes; Hiccup's shortcuts for ids, classes, and nested tags; and more. I'll soon include it in the Early Access Program, so get ready for the pre-sale.

The Re-frame Building Blocks Guide: Interceptors

I've added a section on Interceptors to The Re-frame Building Blocks Guide. Interceptors are an intermediate to advanced concept and they're not really needed for most tasks. But I've put them in for completeness. I've also expanded the Reactive Subscriptions section to show how to combine multiple subscriptions into one.