Avoid match for error handling where it makes sense

src/converter/ddr2osu.rs

@@ -284,10 +284,7 @@ impl ssq::Step {
                 }
             }
             ssq::Step::Shock { beats } => {
-                let columns = match shock_step_generator.next() {
+                let columns = shock_step_generator.next().unwrap_or_else(Vec::new);
-                    Some(columns) => columns,
-                    None => vec![],
-                };
 
                 for column in columns {
                     hit_objects.push(beatmap::HitObject::HitCircle {

src/main.rs

@@ -166,13 +166,6 @@ struct BatchDDR2osu {
     convert: converter::ddr2osu::Config,
 }
 
-fn get_basename(path: &PathBuf) -> Option<&str> {
-    match path.file_stem() {
-        Some(stem) => stem.to_str(),
-        None => None,
-    }
-}
-
 fn read_musicdb(path: &PathBuf) -> Result<musicdb::MusicDB> {
     let extension = path.extension().and_then(|ext| ext.to_str()).unwrap_or("");
 
@@ -372,7 +365,10 @@ fn main() -> Result<()> {
         }
         SubCommand::DDR2osu(opts) => {
             let basename = opts.basename.clone().unwrap_or(
-                get_basename(&opts.ssq_file)
+                opts.ssq_file
+                    .file_stem()
+                    .map(|stem| stem.to_str())
+                    .flatten()
                     .map(|basename| basename.to_string())
                     .ok_or_else(|| {
                         anyhow!(