refactor: use match with cmp instead of bunch of if's

src/main.rs

@@ -1,14 +1,16 @@
-use std::{env::args_os, ffi::OsString, process::ExitCode};
+use std::{cmp::Ordering, env::args_os, ffi::OsString, process::ExitCode};
 
 use izanami::{run_file, run_prompt, RunError};
 
 fn main() -> ExitCode {
     let args: Vec<OsString> = args_os().collect();
 
-    if args.len() > 2 {
+    match args.len().cmp(&2) {
+        Ordering::Greater => {
             println!("usage: izanami [script]");
             return ExitCode::from(64);
-    } else if args.len() == 2 {
+        }
+        Ordering::Equal => {
             let result = run_file(args[1].to_str().unwrap());
 
             if let Err(RunError::FileReadError(e)) = result {
@@ -27,7 +29,8 @@ fn main() -> ExitCode {
             if let Err(RunError::ParseError) = result {
                 return ExitCode::from(75);
             }
-    } else {
+        }
+        Ordering::Less => {
             let result = run_prompt();
 
             if let Err(res) = result {
@@ -35,6 +38,7 @@ fn main() -> ExitCode {
                 return ExitCode::from(1);
             }
         }
+    }
 
     ExitCode::SUCCESS
 }