Fix minor warnings and debug log

src/debug.rs

@@ -1,12 +1,12 @@
-use std::num::NonZeroUsize;
+// use std::num::NonZeroUsize;
 
 #[derive(Debug, Clone)]
 pub struct DebugLog {
     enabled: bool,
     current: String,
     history: Vec<String>,
-    max_history: Option<NonZeroUsize>,
-    pos: usize,
+    // max_history: Option<NonZeroUsize>,
+    // pos: usize,
 }
 
 impl DebugLog {
@@ -15,8 +15,8 @@ impl DebugLog {
             enabled: false,
             current: String::new(),
             history: vec![],
-            max_history: None,
-            pos: 0,
+            // max_history: None,
+            // pos: 0,
         }
     }
 
@@ -53,6 +53,10 @@ impl DebugLog {
     pub fn enable(&mut self) {
         self.enabled = true;
     }
+
+    pub fn enabled(&self) -> bool {
+        self.enabled
+    }
 }
 
 impl std::fmt::Write for DebugLog {