Difference Between Clojure, Kotlin and Scala

Intro

The JVM (Java Virtual Machine) ecosystem is home to several powerful languages, each bringing unique features and paradigms. Clojure, Kotlin, and Scala stand out as prominent options for developers working within the JVM environment. Here's a comparison of these languages, focusing on their integration with the JVM and JDK.

Clojure

Clojure is a dynamic, functional programming language inspired by Lisp. It emphasizes immutability, concurrency, and simplicity.

JVM:

• generates bytecode that runs on the JVM

• can call Java classes and methods making it ideal for integrating Java libraries, but it does not go well with Java Frameworks because they are written for OOP where Clojure is pure functional language

• compilation is dynamic, but it supports ahead-of-time (AOT) compilation for creating standalone

• has a REPL (Read-Eval-Print Loop)

JDK:

• it relies heavily on the JDK for standard functionalities like I/O, collections, and threading
• doesn’t impose a specific type system, it provides mechanisms to interoperate with Java’s static types when needed

Strengths:

• ideal for rapid prototyping and data-driven applications
• exceptional support for concurrency via immutable data structures and software transactional memory

Drawbacks:

• not statically typed, which can be a disadvantage for some use cases
• less suitable for complex object-oriented designs typical in Java-heavy environments.

Kotlin

Kotlin is a statically-typed, modern programming language developed by JetBrains. It was designed to improve upon Java by enhancing developer productivity while maintaining 100% interoperability with Java.

JVM:

• compiles directly to JVM bytecode
• allows mixing Kotlin and Java code within the same project - supports scripting and can even compile to JavaScript or native code (using Kotlin/Native)

JDK:

• fully compatible with the JDK
• simplifies Java’s verbose APIs by introducing features like extension functions, null safety, concise syntax and coroutines

Strengths:

• null safety at the language level reduces the likelihood of NullPointerException
• a shallow learning curve for Java developers due to its similar syntax and structure
• officially supported for Android development by Google

Drawbacks:

• features (like higher-order functions) can introduce complexity for new developers

Scala

Scala is a statically-typed functional and object-oriented programming language. It offers a robust feature set and is widely used in large-scale applications, particularly in data engineering and distributed systems.

JVM:

• compiles to JVM bytecode and supports full interoperability with Java, although its more
• has a REPL (Read-Eval-Print Loop)

JDK:

• it's standard library replaces much of the JDK functionality with more functional approcah
• preference for functional paradigms can make combining Scala with Java codebases hard.

Strengths:

• highly expressive, with support for advanced features like higher-kinded types, pattern matching, and functional constructs.

Drawbacks:

• steeper learning curve due to its rich feature set and advanced type systems
• compilation times can be longer

Choosing the Language

Clojure: Best for projects that benefit from functional programming, immutability, and dynamic typing. Ideal for startups, data-heavy applications, and scripting.

Kotlin: Suited for teams migrating from Java but wish to use Java Framweworks like Spring. Standard for developing Android apps. Its modern features make it a great choice for most JVM-based applications.

Scala: The go-to language for distributed systems, big data processing, and teams familiar with functional programming.