Function eval 

pub fn eval(
    world: Tracked<'_, dyn World + '_>,
    library: &LazyHash<Library>,
    traced: Tracked<'_, Traced>,
    sink: TrackedMut<'_, Sink>,
    route: Tracked<'_, Route<'_>>,
    source: &Source,
) -> SourceResult<Module>

Evaluate a source file and return the resulting module.