some cleanup

ghostcell/examples/dlist_arc.rs

@@ -3,12 +3,10 @@ use ghostcell::GhostToken;
 use std::sync::RwLock;
 use std::{fmt, thread, time};
 
-fn print_list<'id, T: fmt::Debug>(list: &NodePtr<'id, T>, token: &GhostToken<'id>) {
-    print!("[");
+fn print_list<'id, T: fmt::Debug>(tag: char, list: &NodePtr<'id, T>, token: &GhostToken<'id>) {
     for d in Node::iter(list, token) {
-        print!("{:?}, ", d);
+        print!("{}{:?}, ", tag, d);
     }
-    print!("]");
 }
 
 fn main() {
@@ -30,7 +28,7 @@ fn main() {
         // Print the list we created
         print!("Numbers: ");
         // This only needs a &GhostToken
-        print_list(&list, &token);
+        print_list(' ', &list, &token);
         println!();
 
         // Oh, let's print it in parallel with thread `a` and thread `b`.
@@ -39,12 +37,8 @@ fn main() {
         // `b`'s can interleave.
         println!("Parallel printing: ");
         rayon::join(
-            ||  for d in Node::iter(&list, &token) {
-                    print!("a{:?} ", d);
-                },
-            ||  for d in Node::iter(&list, &token) {
-                    print!("b{:?} ", d);
-                }
+            ||  print_list('a', &list, &token),
+            ||  print_list('b', &list, &token),
         );
         println!();
 
@@ -59,7 +53,7 @@ fn main() {
         });
 
         print!("Post deletion: ");
-        print_list(&list, &token);
+        print_list(' ', &list, &token);
         println!();
 
         // RwLock on the token to allow concurrent writes and reads.
@@ -72,15 +66,11 @@ fn main() {
         rayon::join(
             || {
                 let token : &GhostToken = &token.read().unwrap();
-                for d in Node::iter(&list, token) {
-                    print!("a{:?} ", d);
-                }
+                print_list('a', &list, &token);
             },
             || {
                 let token : &GhostToken = &token.read().unwrap();
-                for d in Node::iter(&list, token) {
-                    print!("b{:?} ", d);
-                }
+                print_list('b', &list, &token);
             }
         );
         println!();
@@ -94,9 +84,7 @@ fn main() {
                 // Sleeps to allow the writer thread to acquire a writer lock.
                 thread::sleep(time::Duration::from_micros(10));
                 let token : &GhostToken = &token.read().unwrap();
-                for d in Node::iter(&list, token) {
-                    print!("r{:?} ", d);
-                }
+                print_list('r', &list, token);
             },
             || {
                 let token : &mut GhostToken = &mut token.write().unwrap();