Ruby: compute path string only once

ruby/extractor/src/extractor.rs

@@ -119,27 +119,28 @@ pub fn extract(
     source: &[u8],
     ranges: &[Range],
 ) -> std::io::Result<()> {
+    let path_str = format!("{}", path.display());
     let span = span!(
         Level::TRACE,
         "extract",
-        file = %path.display()
+        file = %path_str
     );
 
     let _enter = span.enter();
 
-    info!("extracting: {}", path.display());
+    info!("extracting: {}", path_str);
 
     let mut parser = Parser::new();
     parser.set_language(language).unwrap();
     parser.set_included_ranges(ranges).unwrap();
     let tree = parser.parse(&source, None).expect("Failed to parse file");
-    trap_writer.comment(format!("Auto-generated TRAP file for {}", path.display()));
+    trap_writer.comment(format!("Auto-generated TRAP file for {}", path_str));
     let file_label = populate_file(trap_writer, path);
     let mut visitor = Visitor {
         source,
         trap_writer,
         // TODO: should we handle path strings that are not valid UTF8 better?
-        path: format!("{}", path.display()),
+        path: &path_str,
         file_label,
         toplevel_child_counter: 0,
         stack: Vec::new(),
@@ -199,7 +200,7 @@ struct ChildNode {
 
 struct Visitor<'a> {
     /// The file path of the source code (as string)
-    path: String,
+    path: &'a str,
     /// The label to use whenever we need to refer to the `@file` entity of this
     /// source file.
     file_label: trap::Label,