refactor: significant digits calculation out of fn main

src/main.rs

@@ -12,6 +12,20 @@ pub fn parse_and_calc(s: &str) -> Float {
     nodes::Nodes::from_str(s).unwrap().evaluate()
 }
 
+pub fn get_significant_digits(n: &Float) -> usize {
+    let raw_string = format!("{n}");
+
+    let mut significant_digits = raw_string.len() - 1;
+    for (i, _) in raw_string.char_indices() {
+        if !raw_string[i..raw_string.len()].contains(|c| matches!(c, '1'..'9')) {
+            significant_digits = i;
+            break;
+        }
+    }
+
+    significant_digits
+}
+
 fn main() {
     let input = match env::args().skip(1).reduce(|x, a| a + &x) {
         Some(s) => s,
@@ -24,14 +38,5 @@ fn main() {
 
     let result = parse_and_calc(&input);
 
-    let result_raw_string = format!("{}", result);
-    let mut significant_digits = result_raw_string.len() - 1;
-    for (i, _) in result_raw_string.char_indices() {
-        if !result_raw_string[i..result_raw_string.len()].contains(|c| matches!(c, '1'..'9')) {
-            significant_digits = i;
-            break;
-        }
-    }
-
-    println!("{result:.significant_digits$}");
+    println!("{result:.0$}", get_significant_digits(&result));
 }