serialize.rs

    let mut registry = TypeRegistryInternal::default();
    registry.register::<f32>();
    registry.register::<bool>();
    registry.register::<Vec2>();
    registry.register::<components::Position>();
    registry.register::<components::KineticBody>();
...
                for entity in entities.iter() {
                    if let Some(location) = world.get_entity_location(*entity) {
                        let archetype = &world.archetypes[location.archetype as usize];

                                for type_info in archetype.types() {
                                    if let Some(registration) = registry.get(type_info.id()) {
                                        if let Some(reflect_component) =
                                            registration.data::<ReflectComponent>()
                                        {
                                            let serializer = unsafe {
                                                let component = reflect_component
                                                    .reflect_component(&archetype, location.index);
                                                ReflectSerializer::new(component, &registry)
                                            };

                                            let json = serde_json::to_string(&serializer).unwrap();

// This allows to introspect and serialize components tagged with:
#[derive(Debug, Reflect, Copy, Clone)]
#[reflect(Component)]
pub struct SomeComponent {
  ...