This document lists things the author likes about Clojure including static typing with schema, parallelism with futures, and templating with Hiccup. It also recommends tools and libraries for Clojure projects like Leiningen, linting with kibit and eastwood, testing with Midje, and frameworks like Luminus and RouteOne. Finally, it suggests next steps of installing Clojure and trying a first project using recommended technologies.

1. Things to in Clojure
Jiri Knesl

2. Things I already like

3. • static typing makes me write types everywhere (inference
helps but only a little)
• schema allows me to type only in places I like
• types are data (you can create them, modify them, merge
them)
• you can add validators to types (only even size of vector?)
• optional keys & Maybe
• Disadvantage: magic happens in runtime :(

4. • https://github.com/prismatic/schema
• Install:
• [prismatic/schema “0.2.1”]
• Require:
• (:require [schema.core :as s])

6. Parallelism for free
• Simple as (future (do something))
• Or Atoms/Agents…
• Or core.async

7. One day
• One day I improved performance of my
application by 100 %
• With only a few characters
• Without need to think
• I put my model queries to (future) and
@deref’d them in template

8. More
parallel/concurrent/async
goodness
• Software Transactional Memory
• Futures, Promises
• Actors
• Core.async
• Actors (more on this later)
• Homoiconicity for the great good

9. Great presentation on topic
“The Future is Parallel, and the
Future of Parallel is Declarative”
Simon Peyton Jones

10. Leiningen everywhere
• lein deps (Clojure is just another dependency)
• lein kibit & lein eastwood (lint)
• lein uberjar
• lein midje
• …

11. Hiccup
• Turing-complete templates
• Compile-time checking
• Adding own helpers & logic became natural
• And templates are shorter
• With RouteOne

12. Hiccup looks like…

13. Things I believe I will like

14. Double-check
https://github.com/cemerick/do
uble-check
now you can test on thousands
of inputs
and then get the minimal input

15. ZMQ-Async
https://github.com/lynaghk/zmq-async

16. http://www.avout.io
distributed atom & ref

17. Pulsar
http://docs.paralleluniverse.co/pulsar/
Erlang-like Actors

18. Next step
• Install Clojure & try your first project
• Luminus framework & RouteOne & Hiccup &
Midje
• Follow @jiriknesl
• E-mail me to jiri@sprintmasters.cz (I would be
happy to help you with transition to functional
programming)