syntax_data: {"ast_node_type":"variable","tokens":[{"end":95,"kind":"keyword","start":0,"text":"FileName::Real(realfile)"}]}
source_snippet:             FileName::Real(realfile) if let RealFileName::LocalPath(local_path) = realfile => {
context_before:         match file {
context_after:                 let (mapped_path, mapped) = self.map_prefix(local_path);