Trace span events.

src/main.rs

@@ -1,6 +1,7 @@
 use crate::parser::document;
 use tracing::trace;
 use tracing::Level;
+use tracing_subscriber::fmt::format::FmtSpan;
 
 mod parser;
 
@@ -15,10 +16,11 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let subscriber = tracing_subscriber::fmt()
         .event_format(format)
         .with_max_level(Level::TRACE)
+        .with_span_events(FmtSpan::ENTER | FmtSpan::EXIT)
         .finish();
     tracing::subscriber::set_global_default(subscriber)?;
-    trace!("TESTING");
+    let parsed = document(TEST_DOC);
     println!("{}\n\n\n", TEST_DOC);
-    println!("{:#?}", document(TEST_DOC));
+    println!("{:#?}", parsed);
     Ok(())
 }