Add length and opCmp to the Queue

source/tanya/container/queue.d

@@ -6,32 +6,22 @@
  * Copyright: Eugene Wissner 2016.
  * License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
  *                  Mozilla Public License, v. 2.0).
- * Authors: $(LINK2 mailto:belka@caraus.de, Eugene Wissner)
+ * Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
  */  
 module tanya.container.queue;
 
+import tanya.container.entry;
+import std.traits;
 import tanya.memory;
 
 /**
- * Queue.
+ * FIFO queue.
  *
  * Params:
  * 	T = Content type.
  */
 struct Queue(T)
 {
-	/**
-	 * Creates a new $(D_PSYMBOL Queue).
-	 *
-	 * Params:
-	 * 	allocator = The allocator should be used for the element
-	 * 	            allocations.
-	 */
-	this(shared Allocator allocator)
-	{
-		this.allocator = allocator;
-	}
-
 	/**
 	 * Removes all elements from the queue.
 	 */
@@ -54,15 +44,147 @@ struct Queue(T)
 	///
 	unittest
 	{
-		auto q = defaultAllocator.make!(Queue!int);
+		Queue!int q;
 
 		assert(q.empty);
 		q.insertBack(8);
 		q.insertBack(9);
 		q.clear();
 		assert(q.empty);
+	}
 
-		defaultAllocator.dispose(q);
+	/**
+	 * Returns how many elements are in the queue. It iterates through the queue
+	 * to count the elements.
+	 *
+	 * Returns: How many elements are in the queue.
+	 */
+	size_t length() const
+	{
+		size_t len;
+		for (const(Entry!T)* i = first.next; i !is null; i = i.next)
+		{
+			++len;
+		}
+		return len;
+	}
+
+	///
+	unittest
+	{
+		Queue!int q;
+
+		assert(q.length == 0);
+		q.insertBack(5);
+		assert(q.length == 1);
+		q.insertBack(4);
+		assert(q.length == 2);
+		q.insertBack(9);
+		assert(q.length == 3);
+
+		q.popFront();
+		assert(q.length == 2);
+		q.popFront();
+		assert(q.length == 1);
+		q.popFront();
+		assert(q.length == 0);
+	}
+
+	version (D_Ddoc)
+	{
+		/**
+		 * Compares two queues. Checks if all elements of the both queues are equal.
+		 *
+		 * Returns: Whether $(D_KEYWORD this) and $(D_PARAM that) are equal.
+		 */
+		int opEquals(ref typeof(this) that);
+
+		/// Ditto.
+		int opEquals(typeof(this) that);
+	}
+	else static if (!hasMember!(T, "opEquals")
+	             || (functionAttributes!(T.opEquals) & FunctionAttribute.const_))
+	{
+		bool opEquals(in ref typeof(this) that) const
+		{
+			const(Entry!T)* i = first.next;
+			const(Entry!T)* j = that.first.next;
+			while (i !is null && j !is null)
+			{
+				if (i.content != j.content)
+				{
+					return false;
+				}
+				i = i.next;
+				j = j.next;
+			}
+			return i is null && j is null;
+		}
+
+		/// Ditto.
+		bool opEquals(in typeof(this) that) const
+		{
+			return opEquals(that);
+		}
+	}
+	else
+	{
+		/**
+		 * Compares two queues. Checks if all elements of the both queues are equal.
+		 *
+		 * Returns: How many elements are in the queue.
+		 */
+		bool opEquals(ref typeof(this) that)
+		{
+			Entry!T* i = first.next;
+			Entry!T* j = that.first.next;
+			while (i !is null && j !is null)
+			{
+				if (i.content != j.content)
+				{
+					return false;
+				}
+				i = i.next;
+				j = j.next;
+			}
+			return i is null && j is null;
+		}
+
+		/// Ditto.
+		bool opEquals(typeof(this) that)
+		{
+			return opEquals(that);
+		}
+	}
+
+	///
+	unittest
+	{
+		Queue!int q1, q2;
+
+		q1.insertBack(5);
+		q1.insertBack(4);
+		q2.insertBack(5);
+		assert(q1 != q2);
+		q2.insertBack(4);
+		assert(q1 == q2);
+
+		q2.popFront();
+		assert(q1 != q2);
+
+		q1.popFront();
+		assert(q1 == q2);
+
+		q1.popFront();
+		q2.popFront();
+		assert(q1 == q2);
+	}
+
+	private unittest
+	{
+		static assert(is(Queue!ConstEqualsStruct));
+		static assert(is(Queue!MutableEqualsStruct));
+		static assert(is(Queue!NoEqualsStruct));
 	}
 
 	/**
@@ -84,13 +206,9 @@ struct Queue(T)
 	 * Params:
 	 * 	x = New element.
 	 */
-	void insertBack(T x)
+	void insertBack(ref T x)
 	{
-		if (allocator is null)
-		{
-			allocator = defaultAllocator;
-		}
-		Entry* temp = make!Entry(allocator);
+		auto temp = allocator.make!(Entry!T);
 		
 		temp.content = x;
 
@@ -105,27 +223,31 @@ struct Queue(T)
 		}
 	}
 
+	/// Ditto.
+	void insertBack(T x)
+	{
+		insertBack(x);
+	}
+
 	/// Ditto.
 	alias insert = insertBack;
 
 	///
 	unittest
 	{
-		auto q = make!(Queue!int)(defaultAllocator);
+		Queue!int q;
 
 		assert(q.empty);
 		q.insertBack(8);
 		assert(q.front == 8);
 		q.insertBack(9);
 		assert(q.front == 8);
-
-		dispose(defaultAllocator, q);
 	}
 
 	/**
 	 * Returns: $(D_KEYWORD true) if the queue is empty.
 	 */
-	@property bool empty() inout const pure nothrow @safe
+	@property bool empty() const
 	{
 		return first.next is null;
 	}
@@ -133,14 +255,12 @@ struct Queue(T)
 	///
 	unittest
 	{
-		auto q = make!(Queue!int)(defaultAllocator);
+		Queue!int q;
 		int value = 7;
 
 		assert(q.empty);
 		q.insertBack(value);
 		assert(!q.empty);
-
-		dispose(defaultAllocator, q);
 	}
 
 	/**
@@ -163,15 +283,13 @@ struct Queue(T)
 	///
 	unittest
 	{
-		auto q = make!(Queue!int)(defaultAllocator);
+		Queue!int q;
 
 		q.insertBack(8);
 		q.insertBack(9);
 		assert(q.front == 8);
 		q.popFront();
 		assert(q.front == 9);
-
-		dispose(defaultAllocator, q);
 	}
 
 	/**
@@ -215,7 +333,7 @@ struct Queue(T)
 	///
 	unittest
 	{
-		auto q = Queue!int(defaultAllocator);
+		Queue!int q;
 
 		size_t j;
 		q.insertBack(5);
@@ -246,32 +364,19 @@ struct Queue(T)
 		assert(q.empty);
 	}
 
-	/**
-	 * Queue entry.
-	 */
-	protected struct Entry
-	{
-		/// Queue item content.
-		T content;
-
-		/// Next list item.
-		Entry* next;
-	}
-
 	/// The first element of the list.
-	protected Entry first;
+	private Entry!T first;
 
 	/// The last element of the list.
-	protected Entry* rear;
+	private Entry!T* rear;
 
-	/// The allocator.
-	protected shared Allocator allocator;
+	mixin DefaultAllocator;
 }
 
 ///
 unittest
 {
-	auto q = Queue!int(defaultAllocator);
+	Queue!int q;
 
 	q.insertBack(5);
 	assert(!q.empty);