Function module_spans 

pub fn module_spans<'db>(
    db: &'db dyn Db,
    module: Module<'db>,
) -> &'db DatafunSpans<'db>

The spans of one module, in the form diagnostics look things up in.

parse_module_full returns the side tables as the parser filled them; this is the same data keyed for lookup. Tracked and keyed on the module, so building it is a cost only the modules something actually reports a diagnostic against pay, rather than every module on every compile.