From 026cf067c872b74252ae1f82e26b5891b043adcb Mon Sep 17 00:00:00 2001
From: "bob.hongbo.zhang" <bob.hongbo.zhang@idea.edu.cn>
Date: Tue, 26 Mar 2024 22:53:47 +0800
Subject: [PATCH 1/2] split types

---
 queue/queue.mbt | 17 +----------------
 queue/types.mbt | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 16 deletions(-)
 create mode 100644 queue/types.mbt

diff --git a/queue/queue.mbt b/queue/queue.mbt
index 68f64c2c6..7aa9450dc 100644
--- a/queue/queue.mbt
+++ b/queue/queue.mbt
@@ -12,21 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-struct Cont[T] {
-  content : T
-  mut next : Cell[T]
-}
-
-enum Cell[T] {
-  Nil
-  Cons(Cont[T])
-}
-
-struct Queue[T] {
-  mut length : Int
-  mut first : Cell[T]
-  mut last : Cell[T]
-}
 
 /// Creates a new empty queue.
 /// 
@@ -64,7 +49,7 @@ pub fn Queue::from_array[T](arr : Array[T]) -> Queue[T] {
 }
 
 /// Tests if two queue cells are equal.
-pub fn op_equal[T : Eq](self : Cell[T], other : Cell[T]) -> Bool {
+fn op_equal[T : Eq](self : Cell[T], other : Cell[T]) -> Bool {
   loop self, other {
     Nil, Nil => true
     Cons({ content: x, next: xs }), Cons({ content: y, next: ys }) => {
diff --git a/queue/types.mbt b/queue/types.mbt
new file mode 100644
index 000000000..5eea82ab6
--- /dev/null
+++ b/queue/types.mbt
@@ -0,0 +1,29 @@
+// Copyright 2024 International Digital Economy Academy
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+priv struct Cont[T] {
+  content : T
+  mut next : Cell[T]
+}
+
+priv enum Cell[T] {
+  Nil
+  Cons(Cont[T])
+}
+
+struct Queue[T] {
+  mut length : Int
+  mut first : Cell[T]
+  mut last : Cell[T]
+}
\ No newline at end of file

From 6b95f921e714869758495e9b7aa61840b44c2e68 Mon Sep 17 00:00:00 2001
From: "bob.hongbo.zhang" <bob.hongbo.zhang@idea.edu.cn>
Date: Tue, 26 Mar 2024 22:58:05 +0800
Subject: [PATCH 2/2] tweak

---
 queue/queue.mbt | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/queue/queue.mbt b/queue/queue.mbt
index 7aa9450dc..3066b3141 100644
--- a/queue/queue.mbt
+++ b/queue/queue.mbt
@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-
 /// Creates a new empty queue.
 /// 
 /// # Example
@@ -52,12 +51,12 @@ pub fn Queue::from_array[T](arr : Array[T]) -> Queue[T] {
 fn op_equal[T : Eq](self : Cell[T], other : Cell[T]) -> Bool {
   loop self, other {
     Nil, Nil => true
-    Cons({ content: x, next: xs }), Cons({ content: y, next: ys }) => {
-      if x != y {
-        break false
+    Cons({ content: x, next: xs }), Cons({ content: y, next: ys }) =>
+      if x == y {
+        continue xs, ys
+      } else {
+        false
       }
-      continue xs, ys
-    }
     _, _ => false
   }
 }