Sorting By Functions in OpenSCAD

Our example demonstrates custom sorting in OpenSCAD. Since OpenSCAD doesn’t have built-in sorting functions or complex data structures like structs, we’ll implement a basic bubble sort algorithm and use it to sort a list of numbers.

// Function to swap two elements in a list
function swap(list, i, j) = 
    [for(k=[0:len(list)-1])
        k == i ? list[j] :
        k == j ? list[i] :
        list[k]];

// Bubble sort implementation
function bubble_sort(list) =
    let(n = len(list))
    [for(i=[0:n-1])
        for(j=[0:n-i-2])
            if(list[j] > list[j+1])
                list = swap(list, j, j+1)][n-1];

// Main function
function main() =
    let(
        numbers = [5, 2, 8, 1, 9, 3],
        sorted_numbers = bubble_sort(numbers)
    )
    sorted_numbers;

// Print the result
echo(main());

In this example:

1. We define a swap function that swaps two elements in a list. This is used by our sorting algorithm.

2. We implement a bubble_sort function. This is a simple sorting algorithm that repeatedly steps through the list, compares adjacent elements and swaps them if they’re in the wrong order.

3. In the main function, we create a list of numbers and sort them using our bubble_sort function.

4. Finally, we use echo to print the sorted list.

To run this program, save it as sorting_example.scad and use OpenSCAD to execute it. You should see the sorted list in the console output.

ECHO: [1, 2, 3, 5, 8, 9]

Note that OpenSCAD is primarily a 3D modeling scripting language, so it doesn’t have many features of general-purpose programming languages. This example demonstrates a basic sorting algorithm implementation, but for more complex operations, you might need to use a different language or external tools in conjunction with OpenSCAD.