treewide: enforce strict clippy check

fix/src/main.rs

@@ -20,33 +20,49 @@ struct Cli {
 enum Command {
     Compile {
         #[clap(flatten)]
-        source: ExprSource,
+        source: ExprSourceArgs,
         #[arg(long)]
         silent: bool,
     },
     Eval {
         #[clap(flatten)]
-        source: ExprSource,
+        source: ExprSourceArgs,
     },
     Repl,
 }
 
 #[derive(Args)]
 #[group(required = true, multiple = false)]
-struct ExprSource {
+struct ExprSourceArgs {
     #[clap(short, long)]
     expr: Option<String>,
     #[clap(short, long)]
     file: Option<PathBuf>,
 }
 
+enum ExprSource {
+    Expr(String),
+    File(PathBuf),
+}
+
+#[expect(
+    clippy::unreachable,
+    reason = "clap's arg group guarantees exactly one of --expr/--file is set"
+)]
+impl From<ExprSourceArgs> for ExprSource {
+    fn from(args: ExprSourceArgs) -> Self {
+        match (args.expr, args.file) {
+            (Some(expr), None) => ExprSource::Expr(expr),
+            (None, Some(file)) => ExprSource::File(file),
+            _ => unreachable!(),
+        }
+    }
+}
+
 fn run_compile(eval: &mut Evaluator, src: ExprSource, silent: bool) -> Result<()> {
-    let src = if let Some(expr) = src.expr {
-        Source::new_eval(expr)?
-    } else if let Some(file) = src.file {
-        Source::new_file(file)?
-    } else {
-        unreachable!()
+    let src = match src {
+        ExprSource::Expr(expr) => Source::new_eval(expr)?,
+        ExprSource::File(file) => Source::new_file(file)?,
     };
     match eval.compile_bytecode(src) {
         Ok(ip) => {
@@ -63,12 +79,9 @@ fn run_compile(eval: &mut Evaluator, src: ExprSource, silent: bool) -> Result<()
 }
 
 fn run_eval(eval: &mut Evaluator, src: ExprSource) -> Result<()> {
-    let src = if let Some(expr) = src.expr {
-        Source::new_eval(expr)?
-    } else if let Some(file) = src.file {
-        Source::new_file(file)?
-    } else {
-        unreachable!()
+    let src = match src {
+        ExprSource::Expr(expr) => Source::new_eval(expr)?,
+        ExprSource::File(file) => Source::new_file(file)?,
     };
     match eval.eval_deep(src) {
         Ok(value) => {
@@ -93,7 +106,9 @@ fn run_repl(eval: &mut Evaluator) -> Result<()> {
                 if line.trim().is_empty() {
                     continue;
                 }
-                let _ = rl.add_history_entry(line.as_str());
+                if let Err(err) = rl.add_history_entry(line.as_str()) {
+                    eprintln!("[WARN] Failed to add history entry: {err}");
+                }
                 if let Some([Some(_), Some(ident), Some(rest)]) = RE.exec(&line) {
                     if let Some(expr) = rest.strip_prefix('=') {
                         let expr = expr.trim_start();
@@ -137,15 +152,15 @@ fn run_repl(eval: &mut Evaluator) -> Result<()> {
 }
 
 fn main() -> Result<()> {
-    fix::logging::init_logging();
+    fix::logging::init_logging()?;
 
     let cli = Cli::parse();
 
     let mut eval = Evaluator::new();
 
     match cli.command {
-        Command::Compile { source, silent } => run_compile(&mut eval, source, silent),
-        Command::Eval { source } => run_eval(&mut eval, source),
+        Command::Compile { source, silent } => run_compile(&mut eval, source.into(), silent),
+        Command::Eval { source } => run_eval(&mut eval, source.into()),
         Command::Repl => run_repl(&mut eval),
     }
 }