When working with Elixir, we often find ourselves immersed in the world of `.exs` files. These script files, different from the standard Elixir application structure defined in `mix.exs`, offer a unique approach to problem-solving. However, many developers may not have delved into the intricacies of Elixir scripting. In this article, we'll explore the possibilities and limitations of Elixir script files to help you harness their potential.
How to write a script in Elixir
Elixir, a functional programming language, can be used for scripting. Here's how to write a script in Elixir:
1. Single File Elixir Scripts:
Elixir allows you to create single-file scripts. You can write your code in a single file with a `.exs` extension, which can be executed with the `elixir` command. You can find more details in the [Phoenix Files on Fly.io].
2. Self-Contained Command Line Scripts:
You can write self-contained command-line scripts using Elixir. Check out this [tutorial] by Alex Koutmos for step-by-step guidance.
3. Using the Scripting Module:
Elixir provides a [Scripting module] that simplifies the process of writing scripts. It's a no-dependency module that makes it easier to start and write scripts in Elixir.
4. Running Elixir Files as Scripts:
Elixir can run scripts that are compiled into memory. This is useful for experimenting. Create a file with a `.exs` extension and execute it with `elixir` as explained in this [guide].
5. Additional Examples:
For more examples of scripting in Elixir, you can explore Wojtek Mach's Mix Install Examples repository mentioned in the [Underjord blog].
6. Organizing Scripts:
You can organize your Elixir scripts by creating a `bin/` directory. Place your `.exs` files there for easy execution, as mentioned in this [thoughtbot article].
These resources provide a comprehensive guide to writing and running scripts in Elixir, making it a versatile choice for various automation and scripting tasks.
Defining Functions in Elixir Scripts
One of the revelations when working with Elixir scripts is that you can define functions just like in a regular Elixir module. The key difference lies in how you call the function at the end of the file.
Let's take a look at an example:
This script reads lines from the standard input and collects them until an empty line is encountered. Then, it processes and displays the collected lines.
To run this script, execute the following command:
For example, when you input:
You will get the output:
Anonymous Functions for Simplicity
If you prefer a more straightforward approach without defining modules or functions, you can use anonymous functions.
Here's an alternative method:
This script achieves the same result as the previous example, but it relies on anonymous functions to streamline the code. It reads lines, collects them until an empty line is encountered, processes the lines, and displays the result. Run the script using the command provided earlier.
Streamlining Input Processing
If you're looking for a more concise way to handle input lines, Elixir scripts offer a streamlined solution:
This script reads lines from the standard input and stops when an empty line is entered. It then processes and displays the collected lines. As with the other examples, run the script using the provided command.
Conclusion
In conclusion, Elixir scripts provide a versatile and efficient way to interact with the Elixir ecosystem outside the traditional application structure. While the code examples in this article may not be groundbreaking, the real challenge often lies in understanding the scoping issues when transitioning from standard Elixir code to scripting.
If you've ever found yourself in a similar situation, struggling to grasp the full potential of Elixir scripting, rest assured that there's more flexibility than you might have initially thought. Elixir scripts can simplify various tasks and offer alternative approaches to problem-solving.
Lastly, if you encounter any limitations or have insights to share, don't hesitate to explore the Elixir documentation. You can even consider making contributions to enhance it further.
In the spirit of open-source collaboration, consider making your own contributions to the Elixir community. Happy scripting!