Erlang vs Hack: What are the differences?

Introduction:

Erlang and Hack are two programming languages that differ in various aspects. In this markdown, we will explore 6 key differences between Erlang and Hack.

1. Concurrency Model: Erlang is known for its built-in support for concurrency and scalability. It has lightweight processes, called "actors," which communicate through message passing. This concurrency model allows Erlang to handle a large number of concurrent tasks efficiently. In contrast, Hack does not have native support for concurrency and instead relies on traditional thread-based models for parallel execution.

2. Static Typing vs. Dynamic Typing: Erlang is a dynamically typed language, meaning that variable types are determined at runtime. This flexibility allows for easy code modification and dynamic behavior. Hack, on the other hand, is a statically typed language that requires variable types to be declared at compile-time. This ensures code correctness and performance optimization but might make the development process more rigid.

3. Platforms & Target Audience: Erlang was designed specifically for creating fault-tolerant and high-availability systems. It is widely used in telecommunication applications and distributed systems. Hack, on the other hand, is a programming language developed by Facebook for their own use. It focuses on web development and is optimized for PHP-based projects, targeting a different set of audiences and use cases.

4. Concurrency Control: Erlang provides built-in tools and techniques for handling concurrency and protecting shared resources, such as a process-based memory model and message passing. These features make it easier to deal with concurrency-related issues like race conditions and deadlocks. In Hack, concurrency control is left to the developer's discretion, requiring the use of external libraries or manual synchronization mechanisms.

5. Error Handling: Erlang has a special error handling mechanism called "let it crash." It encourages developers to isolate and handle errors at a local level instead of trying to catch all exceptions centrally. This approach allows for fault-tolerant systems that can recover from failures without affecting the whole application. In Hack, error handling is more traditional, relying on try-catch blocks for exception handling.

6. Tooling and Ecosystem: Erlang has a mature ecosystem with a wide range of tools and libraries that facilitate development, testing, and deployment. It has been widely adopted and has a large and active community. Hack, being a relatively newer language, has a smaller ecosystem with fewer tools and libraries available. However, being developed by Facebook, it has extensive support for their own frameworks and technologies.

In summary, Erlang and Hack differ in their concurrency models, typing systems, target audience, concurrency control mechanisms, error handling approaches, and ecosystem maturity.