Channels in OpenSCAD

In OpenSCAD, there isn’t a direct equivalent to channels or goroutines as it’s primarily a 3D modeling scripting language. However, we can demonstrate a similar concept using modules and function calls to show how data can be passed between different parts of a script.

// Create a module that generates a message
module generate_message() {
    message = "ping";
    echo(str("Generated message: ", message));
    message;
}

// Create a module that receives and processes a message
module process_message(msg) {
    echo(str("Received message: ", msg));
}

// Main script
function main() = 
    let(
        message = generate_message()
    )
    process_message(message);

main();

In this OpenSCAD script:

1. We define a generate_message() module that creates a message. This is analogous to sending a value into a channel in the original example.

2. We define a process_message(msg) module that receives and processes a message. This is similar to receiving a value from a channel.

3. In the main() function, we call generate_message() and pass its result to process_message(). This mimics the flow of data from one part of the program to another, similar to how channels work in concurrent programming.

4. Finally, we call the main() function to execute our script.

When we run this program, the message “ping” is successfully passed from the generate_message() module to the process_message() module, demonstrating a simple form of data flow.

To run the program, save it as message_passing.scad and open it in the OpenSCAD application. The console output will show:

ECHO: "Generated message: ping"
ECHO: "Received message: ping"

While this example doesn’t demonstrate concurrency as in the original, it shows how we can structure our OpenSCAD code to pass data between different parts of the script, which is the core concept behind channels in concurrent programming languages.

OpenSCAD is primarily used for creating 3D models, so this example is more of a conceptual demonstration rather than a practical use case. In real OpenSCAD projects, you would typically use these techniques to pass parameters between different parts of your 3D model definitions.