Initialization Code

If you use initializers you might place some initialization code on top of the workbench's body (before the first initializer).

The initialization code is just allowed to define some constants which then can be used in all following code (including code within initializers and functions).

sketch Wheel(radius: Length) {
    // init code
    const FACTOR = 2.0;

    // initializer
    init(diameter: Length) {
        radius = into_radius(diameter);
    }

    // function
    fn into_radius(diameter: Length) {
        // use constant FACTOR from init code
        diameter / FACTOR
    }

    // set property diameter and use FACTOR from init code
    prop diameter = radius * FACTOR;

    // code body
    std::geo2d::Circle(radius);
}

std::debug::assert_eq([Wheel(radius = 5cm).radius, 5cm]);
std::debug::assert_eq([Wheel(radius = 5cm).diameter, 10cm]);

If there are no initializers, the initialization code is just part of the building code.

Restrictions

Cannot access building plan in initialization code

sketch Wheel(radius: Length, thickness = 5mm) {
    use std::geo2d::Circle;

    const _ = radius * 2; // error: cannot use radius from building plan

    init(diameter: Length) {
        radius = diameter / 2;
    }
    Circle(radius + thickness) - Circle(radius)
}

Wheel(radius = 1cm);