Significantly simplified opcode decoding; all clippy warnings fixed.

src/app.rs

@@ -1,5 +1,6 @@
 use crate::chip_core::{ ChipCore };
 use std::path::PathBuf;
+use std::process::Command;
 use std::time::{ Duration, Instant };
 use minifb::{ Key, KeyRepeat, Menu, Window, WindowOptions };
 
@@ -95,9 +96,20 @@ impl App {
         self.window.set_title(title.as_str());
     }
 
+    fn clear_console() {
+        if cfg!(target_os = "windows") {
+            let _ = Command::new("cmd").args(["/C", "cls"]).status();
+        }
+        else {
+            let _ = Command::new("clear").status();
+        }
+    }
+
     fn check_seconds_timer(&mut self) {
         if self.seconds_timer.elapsed() >= Duration::from_secs(1) && self.rom_loaded && !self.chip_paused {
             let avg_exec_time = (self.execute_times / self.execute_count as f64) * 1000.0;
+
+            Self::clear_console();
             println!("Average execute time: {:.3} ms", avg_exec_time);
 
             self.execute_times = 0.0;