Clojure Documents

Table of Contents

• 1. Introduction
• 2. Why is Clojure such a nice idea
• 3. Libraries / frameworks
  • 3.1. DI / IoC
• 4. References

1. Introduction

This is information and links about the Clojure programming language. This reason for this document is mainly for myself so I don’t have to remember all of these details.

2. Why is Clojure such a nice idea

1. State and identity are not conflated

   • Usually everything you do in Clojure is immutable

     • That is usually not a problem thanks to structural sharing

     • When mutability really is required (no place oriented programming)

     • It means that usually a location in memory holding a location will not be changed after it is allocated. Place Oriented Programming is a form of premature optimization.

   • When you must have mutable stuff, that state can be managed really well:

     • Atoms

     • Agents

     • Refs and Software Transactional Memory

     • Locks

     • Future, Promise

     • CSP (core.async)

2. Dynamically typed (compile time) and strongly typed (run time) language makes for more readable code.

   • However, you can add type hints for performance reasons (static typing).

3. Code is data and data is code (homoiconicity)

   • https://www.booleanknot.com/blog/2016/12/20/code-is-data.html

4. Very clean code without much ceremony

   • You can do the same in C++ or Java. But is it less readable.

Downside of Clojure: it’s pretty strange coming from any mainstream imperative programming language.

3. Libraries / frameworks

3.1. DI / IoC

1. https://github.com/weavejester/integrant

   • Is used in Duct

2. https://github.com/tolitius/mount

   • Is used in Luminus

3. https://github.com/aroemers/mount-lite

   • http://aroemers.github.io/mount-lite/

   • https://github.com/dryewo/mount-lite-example

   • https://cljdoc.org/d/functionalbytes/mount-lite/

4. https://github.com/aroemers/system

5. https://github.com/stuartsierra/component

   • https://functionalbytes.nl/clojure/component/reloaded-workflow/2019/05/28/component-lite.html

6. https://github.com/vspinu/commix

Some thoughts on Component and Mount: https://yogthos.net/posts/2016-01-19-ContrastingComponentAndMount.html/ An application that used both Mount and Integrant: https://github.com/serioga/webapp-clojure-2020

4. References

1. Excellent introduction to Clojure: https://grison.me/2020/04/04/starting-with-clojure/

2. Building a Drug Dealer API

   1. https://medium.com/@shivekkhurana/learn-clojure-by-building-a-drug-dealer-api-part-1-83bd4adb9946

   2. https://medium.com/@shivekkhurana/learn-clojure-by-building-a-drug-dealer-api-part-2-de8c47512a71

   3. https://medium.com/@shivekkhurana/learn-clojure-by-building-a-drug-dealer-api-part-3-endgame-b12717164574

3. Much informatio nabout Clojure cli tools

4. Hosted on the JVM: https://www.clojure.org

   • https://clojure.org/api/cheatsheet

5. Hosted by JavaScript: https://clojurescript.org

6. Hosted by .Net runtimes (CLR): https://github.com/clojure/clojure-clr

7. https://search.maven.org/

   • Get Clojure from this Maven repository

8. https://clojars.org/

   • Rest of the Clojure libraries can be found here

9. https://oli.me.uk/clojure-projects-from-scratch/

10. https://tirkarthi.github.io/clojure/2017/12/11/clj-tools-repl.html

11. https://curiousprogrammer.net/

12. https://www.booleanknot.com/

    • Website for author of may Clojure libraries, ao: Integrant, Compojure and Duct. https://clojuredays.org/

13. https://www.clojure-toolbox.com/

14. https://practicalli.github.io/

    • https://practicalli.github.io/spacemacs/evaluating-clojure/

    • https://practicalli.github.io/blog/posts/clojure-web-server-cli-tools-deps-edn/