Structs in OpenSCAD

Based on the provided Go code, here is the equivalent in OpenSCAD with a suitable explanation.

Structs are a way to group together variables under a single name. Even though OpenSCAD does not have built-in structures like other programming languages, we can use dictionaries (collections of key-value pairs) to achieve a similar effect.

Structs in OpenSCAD#

In OpenSCAD, we can simulate structs using dictionaries. Here’s how you can define and use them.

// Define a person dictionary
person = [
    "name": "",
    "age": 0
];

// Function to create a new person
function newPerson(name) = [
    "name": name,
    "age": 42  // Default age
];

// Main code
people = [
    ["name": "Bob", "age": 20],
    ["name": "Alice", "age": 30],
    ["name": "Fred", "age": 0],
    ["name": "Ann", "age": 40],
    newPerson("Jon")
];

// Print the people
for (p = people) {
    echo(p);
}

// Access and modify fields
s = ["name": "Sean", "age": 50];
echo(s["name"]);

sp = s;  // In OpenSCAD, this creates a copy
sp["age"] = 51;
echo(sp["age"]);

// Anonymous dictionary
dog = [
    "name": "Rex",
    "isGood": true
];
echo(dog);

To run the script, save it as structs.scad and load it in the OpenSCAD environment. The echo statements will display the dictionary contents in the console output of OpenSCAD.

Explanation:#

1. person dictionary: Here, we define a generic template for a person dictionary with “name” and “age” fields.
2. newPerson function: This function creates a new person dictionary with the given name and a default age of 42.
3. Main code: We create a list of person dictionaries, including some with fixed names and ages, and one using the newPerson function for initialization.
4. Printing: The for loop iterates over the list of people and prints each dictionary using the echo function.
5. Access and modify fields: We demonstrate accessing a field in the dictionary and modifying it.
6. Anonymous dictionary: Similar to unnamed structs, we directly define and use a dictionary for a dog.

By organizing data in dictionaries, we can achieve a struct-like grouping of variables in OpenSCAD.