Go vs ClojureScript

Goroutines are "lightweight threads" that runs on OS threads. They provide a simple way for concurrent operations — prepending a function with go will execute it concurrently. It utilizes channels for communication between goroutines which aids to prevent races and makes synchronizing execution effortless across goroutines. The maximum number of OS threads goroutines can run on may be defined at compile time with the GOMAXPROCS variable.

The language is designed in a manner that seems logical. Syntax is simplified to reduce burden on the programmer and compiler developers.

Go has a solid team of engineers working on it (some of the best networking engineers in the world are working on Go). Up until now, the great engineering of the language has compensated for its lack of power.

Only features deemed critical are added to the language to prevent cruft from working its way into the language. The language is small enough to fit inside one's head without having to repeatedly open documentation. Documentation is hosted on an official webpage in a manner that is simple to read and understand.

Compiled binaries are fast — about as fast in C in most cases. Compiles on every OS without effort — truly cross-platform compiler. As a result of the fast compilation speed, you can use the gorun program to use go source code as if it was a scripting language.

The idiomatic approach to writing a Go software project is to perform test-driven development with unit testing. Every source code file should have an associated *_test.go file which tests functions in the code.

This helps keep every programmer on the same page in a project and eliminates arguments over formatting styles.

Go software can be immediately installed, regardless of your operating system, package manager, or processor architecture with the go get command. Software is compiled statically by default so there is no need to worry about software dependencies on the client system. Makefiles and headers are no longer necessary, as the package system automatically resolves dependencies, downloads source code and compiles via a single command: go build.

The language promotes programming in a specific idiomatic style, which helps keep every programmer on the same page.

Go was started as a systems language but now it has fully committed in the niche of networking services. This has been a brilliant move by Go because it allows them to capitalize on the immense talent of the Go engineering team (who are in the most part network engineers).

In a world dominated by Java EE and slow scripting language, Go was a breath of fresh air and it continues to be one of the most powerful languages if you want to build networking services.

All types are essentially objects, be they type aliases or structs. The compiler automatically associates types to their methods at compile time. Those methods are automatically associated to all interfaces that match. This allows you to gain the benefits of multiple inheritance without glue code. As a result of the design, classes are rendered obsolete and the resulting style is easy to comprehend.

Godoc is provided to automatically generate API documentation for Go projects. Godoc also hosts its own self-contained web server that will list documentation for all installed packages in your Go path.

This naturally also supports first class and high order functions, so you may pass functions as variables to other functions.

Go is blazing fast, but easier to write than Python, JS, Ruby, or many other dynamic languages.

Every Go source file contains a package line that indicates which package a file belongs to. If the name of the package is 'main', it indicates that this is a program that will be compiled into a binary. Otherwise, it will recognize that it is a package.

As long as every source code file in a directory has the same package name, the compiler will automatically concatenate all of the files together during the compilation process.

This conveniently eliminates the need to create temporary variables.
Fibonacci example: x, y = y, x+y

Any variable, type and function whose name begins with a capital letter will be exported by a project, while all other code remains private. There is no longer a need to signify that a piece of code is 'private' or 'public' manually.

Figwheel builds your ClojureScript code and hot loads it into the browser as you are coding! Every time you save your ClojureScript source file, the changes are sent to the browser so that you can see the effects of modifying your code in real time.

Lispness makes ClojureScript trivial to comprehend after an initial learning overhead.

Clojure and ClojureScript are designed to be able to interact with their host. So the language by design makes it is easy to use existing JS libraries.

Google's Closure Library converts regular JavaScript into a highly optimized form - including dead code analysis/elimination. It can even remove pieces of unused code from 3rd party libraries (eg, if you import jQuery but only use one function, Google Closure includes only that piece).

Clojure is also able to run web servers, so one can reap similar benefits to NodeJS in terms of sharing code between client and server.

Both Leiningen and Boot are great build tools that manage code dependencies and deployment.

ClojureScript has superb wrappers around React.js (see Reagent) that make building single-page apps a breeze. With figwheel, it's a web dev experience unlike any other -- hotloaded code, repl interaction, and instantly reflected changes make good development fun and fast. You can add things like Garden to make CSS-writing part of the same holistic experience and suddenly all development is a pleasant, smooth process.

From the creator of Clojure:
Spec is a new core library (Clojure 1.9 and Clojurescript) to support data and function specifications in Clojure.
Writing a spec should enable automatic: Validation, Error reporting, Destructuring, Instrumentation, Test-data generation and Generative test generation.