pub type SpanLookup<'a> = &'a dyn Fn(Option<&str>, &str) -> Option<Span>;Expand description
Where a part of a map is in its FML text: the map’s canonical URL (the trace’s source) and
the part’s location (StructureMap.group[0].rule[1]). For maps compiled from FML, this comes
from fml_model::Locations.