refactor: simplify input logic

src/main.rs

@@ -7,14 +7,15 @@ use std::{
 use tylc as lib;
 
 fn main() -> ExitCode {
-    let input = match env::args().skip(1).rev().reduce(|x, a| a + &x) {
+    let input = env::args()
-        Some(s) => s,
+        .skip(1)
-        None => {
+        .rev()
+        .reduce(|x, a| a + &x)
+        .unwrap_or_else(|| {
             let mut buf = String::new();
             io::stdin().read_to_string(&mut buf).unwrap();
             buf
-        }
+        });
-    };
 
     match lib::formatting::pretty_eval(input, 10) {
         Ok(s) => println!("{s}"),