style: don't bury fn main

src/main.rs

@@ -8,6 +8,21 @@ use rug::Float;
 
 mod nodes;
 
+fn main() {
+    let input = match env::args().skip(1).reduce(|x, a| a + &x) {
+        Some(s) => s,
+        None => {
+            let mut buf = String::new();
+            io::stdin().read_to_string(&mut buf).unwrap();
+            buf
+        }
+    };
+
+    let result = parse_and_calc(&input);
+
+    println!("{result:.0$}", get_significant_digits(&result));
+}
+
 pub fn parse_and_calc(s: &str) -> Float {
     nodes::Nodes::from_str(s).unwrap().evaluate()
 }
@@ -47,18 +62,3 @@ pub fn get_significant_digits(n: &Float) -> usize {
 
     significant_digits
 }
-
-fn main() {
-    let input = match env::args().skip(1).reduce(|x, a| a + &x) {
-        Some(s) => s,
-        None => {
-            let mut buf = String::new();
-            io::stdin().read_to_string(&mut buf).unwrap();
-            buf
-        }
-    };
-
-    let result = parse_and_calc(&input);
-
-    println!("{result:.0$}", get_significant_digits(&result));
-}