Ranked in these QuestionsQuestion Ranking
Pro Has Typeclasses and RankNTypes
Pro Type safety
Compiling should be your first unit test. A tight type system (static and hopefully strong) will catch many logic errors that are often difficult to spot through debugging. In languages like PureScript, if it compiles, it often runs properly.
Pro Modules can be compiled to CommonJS
Pro High performance FFI code
Pro Has row polymorphism and extensible effects
Pro Awesome web frameworks
Halogen (VDOM, similar to ELM)
And hit these up with Signals, Isolated/(Managed?) Components, powerful functions and FFI
Pro Great tooling support
Since Kotlin is made by Jetbrains (the developers of IntelliJ IDEA) so it stands to reason that the IntelliJ support for Kotlin is also great. Besides that, Kotlin also works well with existing Java tools such as Eclipse, Maven, Gradle, Android Studio, etc...
Pro Easy adoption for existing Java programmers
Kotlin runs on the JVM and Java interoperability has been one of the main objectives since the language was born. It runs everywhere Java does; web servers, mobile devices (Android), and desktop applications. It also works with all the major tools in the Java ecosystem like Eclipse, IntelliJ, Maven, Ant, Gradle, Spring Boot, etc.
All of this makes adoption extremely easy even for existing Java projects. On top of this there's also ensured Type safety and less boilerplate code needed.
Pro Easy to learn if you have prior programming experience
Kotlin's syntax is extremely easy to understand. The language can be picked up in a few hours just by reading the language reference.
Pro No runtime overhead
The standard library is relatively small and tight. It mostly consists of focused extensions of the Java standard library and as such adds no additional runtime overhead to existing Java projects.
Pro Officially supported for Android development
Starting with version 3.0 of Android Studio, Kotlin support will be built-in. This means that it's now easier than ever to use Kotlin for existing Android projects or even start writing Android apps only with Kotlin from scratch.
This also means that Kotlin and Kotlin plugins for Android Studio will be fully supported in the future and their likelihood of being abandoned is quite small since Google is fully embracing the language for their Android ecosystem (alongside Java and C++).
Pro Low-risk adoption for existing Java codebases
Since it has such a good interoperability with Java, Java libraries, and Java tools. It can be adopted for an existing Java codebase at little to no cost. The codebase can be converted from Java to Kotlin little by little without ever disrupting the functionality of the application itself.
Pro Does not impose a particular philosophy of programming
It's not overly OOP like Java and it does not enforce strict functional paradigms either.
Pro Is built to solve industrial problems
Kotlin has been designed and built by developers who have an industrial background and not an academic one. As such, it tries to solve issues mostly found in industrial settings. For example, the Kotlin type system helps developers avoid null pointer exceptions. Reasearch languages usually do not have
null at all, but APIs and large codebases usually need
Con Lots of dependencies needed to get started
Purescript is written in Haskell, but meant to be used with Node.js. As a result, to get started , users must install ghc, cabal, node.js, grunt, and bower. Purescript also has its own compiler, and different semantics form Haskell, and so even after installing, there's still some overhead to getting productive with Purescript.
Con Restrictive FFI
Con Lack of good IDE/tooling support.
Con Slow compilation
On large project, for example Halogen
Con May be hard for programmers already used to imperative style to learn functional programming from Kotlin
Since Kotlin does not enforce any particular paradigms and is not purely functional, it can be pretty easy to fall back to imperative programming habits if a programmer comes from an imperative background.
Con The need for Java interoperability has forced some limitations
The need to make Kotlin interoperable with Java has caused some unintuitive limitations to the language design.