Replace use of unstable Option::flatten() with and_then()

src/commands/save.rs

@@ -59,7 +59,7 @@ fn save(
             // If there is no filename, check the metadata for the origin filename
             if input.len() > 0 {
                 let origin = input[0].origin();
-                match origin.map(|x| source_map.get(&x)).flatten() {
+                match origin.and_then(|x| source_map.get(&x)) {
                     Some(path) => match path {
                         SpanSource::File(file) => {
                             full_path.push(Path::new(file));

src/commands/tags.rs

@@ -38,7 +38,7 @@ fn tags(args: CommandArgs, _registry: &CommandRegistry) -> Result<OutputStream,
                 dict.insert("end", Value::int(span.end as i64));
                 tags.insert_tagged("span", dict.into_tagged_value());
 
-                match origin.map(|x| source_map.get(&x)).flatten() {
+                match origin.and_then(|x| source_map.get(&x)) {
                     Some(SpanSource::File(source)) => {
                         tags.insert("origin", Value::string(source));
                     }