Trait Pluggable

Source

pub trait Pluggable: PluggableFields + PluggableMethods {
    // Required method
    fn name(&self) -> &'static str;

    // Provided methods
    fn fields(&self) -> Vec<Field> { ... }
    fn methods(&self) -> Vec<Method> { ... }
    fn class(&self) -> Class { ... }
}

Expand description

An object that can be plugged into a scripting language.

Can be automatically derived by placing #[pluggable] on a struct.

When implementing Pluggable, it is necessary to have both a struct and an impl, with both having the #[pluggable] attribute.

This has been split up into two other traits

PluggableFields
`PluggableMethods

This is because the syntax extender can not see all of the code - it can only see the thing it’s operating on. This is why we need an attribute on the struct and the impl. We can’t implement a trait twice, each time overriding a specific method.

Because of this, it is necessary to mark both the struct and the impl with the pluggable attribute. It’s not the prettiest, but it does work.