C to Erlang

May 23, 2024

In the realm of programming languages, going from one language/paradigm to another often mark significant milestones in a developer’s journey. Whether driven by curiosity, necessity, or a desire for innovation, exploring new languages can open doors to fresh perspectives and opportunities. In this blog post, we delve into the switch from C programming to Erlang — a journey marked by distinct paradigms, philosophies, and potentials.

C has long stood as a stalwart in the realm of systems programming, renowned for its efficiency, versatility, and low-level control. Yet, as software systems grow in complexity and demand, the need for robustness, scalability, and fault tolerance becomes increasingly paramount. It’s within this context that developers often find themselves drawn to Erlang — a language celebrated for its concurrency model, fault tolerance, and distributed computing capabilities.

This blog post aims to serve as a guiding light for developers embarking on the transition from C to Erlang. We’ll explore the motivations driving this shift, delve into the core differences between the two languages, and provide practical insights, tips, and resources to ease the transition process. Whether you’re a seasoned C programmer seeking new horizons or a curious explorer venturing into the world of Erlang, this post is crafted to illuminate your path and empower your journey.


Understanding C and Erlang


Overview of C

C stands as a cornerstone in the landscape of programming languages, renowned for its efficiency, performance, and low-level control. Developed in the early 1970s by Dennis Ritchie at Bell Labs, C was designed with a focus on system programming, making it well-suited for tasks such as operating systems development, embedded systems programming, and performance-critical applications. Its simplicity, portability, and close-to-the-hardware nature have cemented its status as one of the most widely used programming languages in the world.


Overview of Erlang

In contrast, Erlang emerges from a different lineage, rooted in the telecommunications industry and designed to address the challenges of building fault-tolerant, distributed systems. Conceived by Joe Armstrong, Robert Virding, and Mike Williams at Ericsson in the late 1980s, Erlang embodies a unique blend of functional programming, concurrency-oriented design, and fault tolerance principles. Originally developed for building telecommunication infrastructure, Erlang has since found applications in a wide range of domains, including web development, financial systems, and real-time communication platforms.


Comparison of language paradigms

At their core, C and Erlang represent distinct programming paradigms — imperative and functional, respectively. C emphasizes mutable state, explicit memory management, and procedural programming, granting developers fine-grained control over hardware resources. In contrast, Erlang embraces immutability, message passing concurrency, and pattern matching, enabling developers to build highly concurrent, fault-tolerant systems with ease. While C’s low-level nature provides unparalleled performance and control, Erlang’s higher-level abstractions prioritize scalability, reliability, and ease of concurrency.


Ecosystem and tooling

Beyond language syntax and paradigms, the ecosystems surrounding C and Erlang also exhibit stark differences. C boasts a rich assortment of libraries, frameworks, and toolchains tailored to system-level development, with widely adopted standards like the C Standard Library (libc) and platforms like GNU Compiler Collection (GCC). On the other hand, Erlang offers a specialized ecosystem geared towards distributed systems, featuring libraries like OTP (Open Telecom Platform) for building fault-tolerant applications and tools like Mix for project management and dependency handling.


Getting started with Erlang


Overview of Erlang

Erlang is a powerful and versatile programming language known for its focus on concurrency, fault tolerance, and distributed computing. Developed by Ericsson for building telecommunication systems, Erlang has evolved into a general-purpose language suitable for a wide range of applications. Its unique features, including lightweight processes, message passing concurrency model, and built-in support for fault tolerance, make it particularly well-suited for developing highly reliable and scalable systems.


Setting up an Erlang development environment

Getting started with Erlang is straightforward, thanks to the availability of pre-built distributions for various operating systems. To set up an Erlang development environment, you’ll need to download and install the Erlang runtime, which includes the Erlang Virtual Machine (BEAM) and a set of command-line tools for compiling and running Erlang code. Alternatively, you can use package managers like Homebrew on macOS or apt-get on Linux to install Erlang.


Introduction to Erlang syntax and programming concepts

For developers familiar with C, moving to Erlang may require some adjustment due to differences in syntax and programming paradigms. While C is an imperative language focused on mutable state and explicit control flow, Erlang follows a functional programming paradigm characterized by immutable data, pattern matching, and recursion. Erlang’s syntax is concise and expressive, with a strong emphasis on pattern matching and list comprehensions.


Here’s a quick overview of some key Erlang concepts for C developers

  • Concurrency: Erlang’s lightweight processes (not to be confused with operating system processes) enable highly concurrent and scalable applications. Each process runs independently and communicates with other processes via message passing.
  • Pattern matching: Erlang’s pattern matching syntax allows developers to destructure data structures and match against specific patterns, making it easy to extract and manipulate values.
  • Fault tolerance: Erlang’s built-in supervisor hierarchy and OTP (Open Telecom Platform) framework provide robust mechanisms for handling errors and failures in distributed systems, ensuring high availability and fault tolerance.
  • Functional Programming: Erlang encourages a functional programming style, where functions are treated as first-class citizens and higher-order functions are used to compose complex behavior from simpler building blocks.


Switching from C to Erlang


Mapping C programming concepts to Erlang

Moving from C to Erlang involves adapting to a different programming paradigm and language ecosystem. While C is an imperative, low-level language focused on manual memory management and explicit control flow, Erlang follows a functional programming paradigm with a focus on immutability, pattern matching, and message passing concurrency.


Here’s a brief comparison of some common C programming concepts and their counterparts in Erlang

  • Variables: In C, variables are mutable and can be reassigned new values. In Erlang, variables are immutable bindings that cannot be changed once assigned.
  • Loops: C uses loops like `for` and `while` for iteration. In Erlang, recursion is the primary mechanism for iteration, with functions calling themselves with modified arguments until a base case is reached.
  • Functions: Both C and Erlang support functions, but Erlang functions are first-class citizens, allowing them to be passed as arguments and returned from other functions. Erlang functions are typically pure, with no side effects.


Differences in memory management, concurrency, and error handling

One of the most significant differences between C and Erlang is in memory management. In C, developers must manually allocate and deallocate memory using functions like malloc and free, leading to potential issues such as memory leaks and segmentation faults. In Erlang, memory management is automatic, with garbage collection handling memory deallocation.

Another key distinction is in concurrency. C relies on operating system threads and locks for concurrency, which can be error-prone and difficult to reason about. In contrast, Erlang’s lightweight processes and message passing concurrency model provide a simpler and safer way to handle concurrent tasks, with built-in support for isolation and fault tolerance.

Error handling is also handled differently in C and Erlang. In C, errors are often signaled via return codes or exceptions, which must be manually propagated and handled. In Erlang, errors are typically represented as tuples containing an error atom and additional information, with built-in mechanisms like try…catch and supervision trees for managing errors and failures.


Tips and Best Practices for Adapting C Code to Erlang

  • Embrace Erlang’s functional programming paradigm: Leverage pattern matching, recursion, and higher-order functions to express complex behavior in a concise and idiomatic way.
  • Take advantage of Erlang’s concurrency model: Use lightweight processes and message passing to build scalable and fault-tolerant systems.
  • Use Erlang’s built-in libraries and OTP: Take advantage of Erlang’s rich ecosystem of libraries and frameworks, including OTP (Open Telecom Platform), for building robust and maintainable applications.

By understanding the differences between C and Erlang and following best practices for adapting C code to Erlang’s functional programming paradigm, developers can unlock the full potential of Erlang and build reliable, scalable, and fault-tolerant systems.


Real-world use cases and examples


Switching from C to Erlang

Erlang has gained popularity in various industries and domains due to its robust concurrency model, fault tolerance, and scalability. Many organizations have successfully switched from C to Erlang to take advantage of these benefits and build high-performance, reliable systems.



One of the most notable use cases for Erlang is in the telecommunications industry. Erlang was originally developed by Ericsson for building telecommunication systems, and it remains a popular choice for building network infrastructure, switches, and protocol implementations. Erlang’s lightweight processes and built-in support for concurrency and distribution make it well-suited for handling the high concurrency and fault tolerance requirements of telecommunications systems.


Messaging systems

Erlang is also widely used for building messaging systems, chat applications, and real-time communication platforms. Its message passing concurrency model and built-in support for distributed computing enable developers to build scalable and fault-tolerant messaging systems that can handle large volumes of concurrent users and messages.


Distributed computing

Erlang’s support for distributed computing makes it an excellent choice for building distributed systems and cloud-native applications. Erlang’s OTP (Open Telecom Platform) provides abstractions for building fault-tolerant distributed systems, including supervisors, gen_servers, and application supervisors. These abstractions enable developers to build distributed systems that can automatically recover from failures and maintain high availability.


Code Examples

Let’s compare examples of common programming tasks or algorithms implemented in C and Erlang to highlight the differences between the two languages.

// Example: Factorial calculation in C
#include <stdio.h>

int factorial(int n) {
   if (n <= 1) {
      return 1;
   } else {
      return n * factorial(n - 1);

int main() {
   int n = 5;
   int result = factorial(n);
   printf("Factorial of %d is %d\n", n, result);
   return 0;


% Example: Factorial calculation in Erlang

factorial(0) -> 1;
factorial(N) when N > 0 -> N * factorial(N - 1).


In this example, we compare the factorial calculation implemented in C and Erlang. While the C version uses recursion and imperative programming, the Erlang version uses pattern matching and functional programming concepts like recursion and guards.

By examining real-world use cases and examples, developers can gain a better understanding of Erlang’s strengths and capabilities and explore its potential applications in their own projects.


Challenges and considerations


Switching from C to Erlang

While switching from C to Erlang offers many advantages, such as improved concurrency and fault tolerance, developers may encounter several challenges along the way. Understanding these challenges and considering strategies for overcoming them can help smooth the transition process.


Learning curve

One of the main challenges when transitioning from C to Erlang is the learning curve associated with functional programming and Erlang’s unique programming model. Developers accustomed to imperative programming in C may find it challenging to adjust to Erlang’s functional programming paradigm, which emphasizes immutability, pattern matching, and recursion. Additionally, Erlang’s syntax and conventions may be unfamiliar to developers coming from a C background, requiring time and effort to master.


Ecosystem differences

Another challenge is the differences in the ecosystems surrounding C and Erlang. While C has a mature ecosystem with a wide range of libraries and tools for various domains, Erlang’s ecosystem may be more specialized and focused on specific use cases such as telecommunications and distributed systems. Developers transitioning to Erlang may need to familiarize themselves with new libraries, frameworks, and development practices to effectively leverage Erlang’s capabilities.


Strategies for overcoming challenges

To overcome these challenges, developers switching from C to Erlang can consider the following strategies:

  1. Invest in learning: Take the time to learn Erlang’s programming model, syntax, and conventions thoroughly. Experiment with small projects and tutorials to gain hands-on experience and reinforce your understanding of Erlang’s concepts.
  1. Seek community support: Engage with the Erlang community through forums, mailing lists, and social media channels. Participate in Erlang meetups, conferences, and workshops to connect with other developers and learn from their experiences.
  1. Explore documentation and resources: Take advantage of Erlang’s extensive documentation and online resources, including tutorials, guides, and books. The official Erlang website and documentation provide comprehensive resources for learning Erlang and its ecosystem.
  1. Practice incremental adoption: Transitioning from C to Erlang doesn’t have to happen all at once. Start by integrating Erlang components into existing C projects or building new features in Erlang alongside existing C code. Gradually increase the use of Erlang as you become more comfortable with the language and its ecosystem.


By recognizing and addressing these challenges proactively, developers can navigate the transition from C to Erlang more effectively and leverage Erlang’s unique capabilities to build robust, scalable, and fault-tolerant software systems.


Resources for learning Erlang


Recommended learning materials


  • Learn You Some Erlang for Great Good! by Fred Hébert: This comprehensive and beginner-friendly book covers Erlang programming concepts, syntax, and best practices with humor and practical examples.
  • Programming Erlang: Software for a Concurrent World by Joe Armstrong: Authored by one of the creators of Erlang, this book provides a deep dive into Erlang’s concurrency model, distributed computing capabilities, and practical Erlang programming techniques.


Tutorials and courses


Community support

Forums and mailing lists

  • Erlang Questions – Stack Overflow: Stack Overflow’s Erlang tag is a valuable resource for asking questions, seeking help with specific Erlang programming problems, and learning from the experiences of other developers.
  • Erlang Slack – EEF: The Erlang Ecosystem Foundation website serves the invitation for the Erlang Slack for Erlang developers, including general discussion, specific Erlang libraries and tools questions, and announcements for Erlang-related events and updates.


Meetups and conferences

  • Erlang MeetUps: Erlang MeetUps are local meetups where Erlang developers can connect, share knowledge, and learn from each other’s experiences: Func Prog Sweden, Virtual BEAM Meetup GMT – Erlang, Elixir and more!
  • Erlang/Elixir Conferences: Attend Erlang and Elixir conferences, such as Code BEAM, and ElixirConf, to network with other Erlang developers, attend talks and workshops on Erlang-related topics, and stay updated on the latest trends and developments in the Erlang ecosystem.


By leveraging these resources and engaging with the Erlang community, developers can accelerate their learning journey, gain insights into Erlang best practices, and build connections with fellow Erlang enthusiasts and experts.



In this blog post, we’ve explored the switching from C to Erlang, uncovering motivations, comparisons, and resources for developers interested in making the switch. Let’s recap the key points discussed.

Motivations for switching: We’ve examined the reasons why developers might consider switching fromC to Erlang, including Erlang’s concurrency model, fault tolerance, and distributed computing capabilities. By leveraging Erlang’s strengths, developers can build highly scalable, fault-tolerant systems suited for modern distributed environments.

Comparing C and Erlang: We’ve highlighted the differences and similarities between C and Erlang, exploring language syntax, paradigms, and ecosystem support. While C offers low-level control and efficiency, Erlang provides abstractions for concurrent and distributed programming, simplifying the development of highly concurrent and fault-tolerant systems.

Resources for learning: We’ve provided a comprehensive list of resources for developers interested in learning Erlang, including books, tutorials, courses, forums, meetups, and conferences. By engaging with these resources and the Erlang community, developers can accelerate their learning journey and gain valuable insights into Erlag programming techniques and best practices.

In conclusion, switching from C to Erlang opens up new possibilities for building scalable, fault-tolerant, and distributed systems. Whether you’re exploring Erlang for the first time or looking to migrate existing C projects, embracing Erlang’s concurrency model and distributed computing capabilities can lead to more robust and resilient software solutions. I encourage you to delve deeper into Erlang, experiment with transitioning your projects, and join the vibrant Erlang community to unlock the full potential of this powerful language.


Additional resources

Check out the Ada Beat Functional Programming blog for more topics, including functional programming principles, summaries of MeetUps, language specific articles, and much more. Whether you’re interested in functional programming theory or practical application, we have something for everyone.