Welcome, young adventurers, to the magical world of Clojure ! Are you ready to explore this fascinating land full of weird symbols, mind-bending tricks, and mysterious creatures (a.k.a. functions)? Great! Let's embark on this wonderful journey together!
Once upon a time in the vast kingdom of programming languages, there was a unique and intriguing language family called Lisp. Lisp is like the wise old wizard of programming languages. It has many children and grandchildren, each with their own sparkling spells and enchantments. And one of its most magical grandkids is Clojure!
Clojure is a modern, powerful, and charming language that inherits the wisdom of Lisp while casting its very own spells . It was created by a talented wizard named Rich Hickey in 2007 and has been captivating explorers ever since!
Clojure has some incredible magic tricks up its sleeve that will make our adventure truly mystical!
Functional Programming: Clojure is a functional language, which means it's all about using spells (functions) to transform data without disturbing the peace (modifying variables). Imagine you have a magic box of crayons : instead of changing colors by breaking or melting them, you can simply cast enchanting spells to create new shades!
Immutable Data Structures: In the land of Clojure, everything is built with unbreakable materials . You can't change things directly; you must create new things based on old ones with the help of magical spells (functions). Imagine having unbreakable legos that you can only rearrange to create new structures, but not break or glue together.
Concurrency: Clojure is adept at handling multiple tasks at the same time , like a magical octopus juggling eight crystal balls! This power makes it great for building applications that need to process lots of information simultaneously.
Before we start casting spells, we need to set up our magic workshop (environment) and get your very own spellbook (editor) ready. To do this, follow these simple steps:
Install the Clojure command line tools on your computer to summon the magical powers of Clojure.
Choose your preferred magical tome (code editor). Popular choices among Clojure wizards include Emacs, Spacemacs, Vim, and Visual Studio Code.
Install Leiningen, a powerful potion that helps manage Clojure projects and brew magical concoctions (dependencies).
Great job! Now we're ready to dive deep into the world of Clojure and start casting spells!
Let's begin our journey by casting a simple spell that greets the magical world around us! Create a new file called
greetings.clj in your spellbook (editor), and write the following incantation:
(defn hello-world 
(println "Hello, Magical World!"))
This spell consists of two distinct parts:
defn: A magic word that defines a new spell (function). Our spell is called
hello-world and takes no magical ingredients (arguments). The empty brackets
 signify that.
println: A magical incantation that sends our message to the enchanted realm of the console . Here, we're sending a greeting to the magical world.
Now, to cast this spell, open your magical terminal and type:
Voila! You've just cast your first spell in Clojure and greeted the magical world!
The real magic of Clojure lies in its ability to combine spells (functions) seamlessly and create powerful enchantments! Let's learn how to conjure functions together by casting a spell that turns water into lemonade :
(defn add-water [water]
(* water 2))
(defn add-lemons [lemonade water]
(+ lemonade water))
(defn water-to-lemonade [water]
(add-lemons (add-water water) water))
(println (water-to-lemonade 5))
The spell first doubles the amount of water using the
add-water function and then adds the original amount of water using the
add-lemons function, creating a delightful lemonade mixture!
The magic here lies within
water-to-lemonade. Like expert potion-making, it combines two other spells (functions) to achieve a greater effect!
Our journey in the land of Clojure has just begun, and there are countless mysteries waiting to be unveiled! Here are a few amazing scrolls of knowledge (resources) to help you further explore this enchanting landscape:
Stay curious and keep exploring, my fellow adventurers! The world of Clojure is vast and full of wonder. And remember, you have the power to create amazing things with the beauty of Lisp and the magic of Clojure!
Grok.foo is a collection of articles on a variety of technology and programming articles assembled by James Padolsey. Enjoy! And please share! And if you feel like you can donate here so I can create more free content for you.