bennadel · March 25, 2014 12:13 · artboard-studio · Dec 5, 2016 · vij1ay · Mar 29, 2017
diff --git a/code-1.htm b/code-1.htm
 <!DOCTYPE html>
 <html>
 <head>
 	<title>Fixed-Length Queue Data Type In JavaScript</title>

 	<script type="text/javascript">


 		// Create a constructor for the fixed-length queue. This is
 		// really more of a FACTORY than a construtor since an
 		// entirely tangential object is returned.
 		function FixedQueue( size, initialValues ){

 			// If there are no initial arguments, default it to
 			// an empty value so we can call the constructor in
 			// a uniform way.
 			initialValues = (initialValues || []);

 			// Create the fixed queue array value.
 			var queue = Array.apply( null, initialValues );

 			// Store the fixed size in the queue.
 			queue.fixedSize = size;

 			// Add the class methods to the queue. Some of these have
 			// to override the native Array methods in order to make
 			// sure the queue lenght is maintained.
 			queue.push = FixedQueue.push;
 			queue.splice = FixedQueue.splice;
 			queue.unshift = FixedQueue.unshift;

 			// Trim any initial excess from the queue.
 			FixedQueue.trimTail.call( queue );

 			// Return the new queue.
 			return( queue );

 		}


 		// I trim the queue down to the appropriate size, removing
 		// items from the beginning of the internal array.
 		FixedQueue.trimHead = function(){

 			// Check to see if any trimming needs to be performed.
 			if (this.length <= this.fixedSize){

 				// No trimming, return out.
 				return;

 			}

 			// Trim whatever is beyond the fixed size.
 			Array.prototype.splice.call(
 				this,
 				0,
 				(this.length - this.fixedSize)
 			);

 		};


 		// I trim the queue down to the appropriate size, removing
 		// items from the end of the internal array.
 		FixedQueue.trimTail = function(){

 			// Check to see if any trimming needs to be performed.
 			if (this.length <= this.fixedSize){

 				// No trimming, return out.
 				return;

 			}

 			// Trim whatever is beyond the fixed size.
 			Array.prototype.splice.call(
 				this,
 				this.fixedSize,
 				(this.length - this.fixedSize)
 			);

 		};


 		// I synthesize wrapper methods that call the native Array
 		// methods followed by a trimming method.
 		FixedQueue.wrapMethod = function( methodName, trimMethod ){

 			// Create a wrapper that calls the given method.
 			var wrapper = function(){

 				// Get the native Array method.
 				var method = Array.prototype[ methodName ];

 				// Call the native method first.
 				var result = method.apply( this, arguments );

 				// Trim the queue now that it's been augmented.
 				trimMethod.call( this );

 				// Return the original value.
 				return( result );

 			};

 			// Return the wrapper method.
 			return( wrapper );

 		};


 		// Wrap the native methods.
 		FixedQueue.push = FixedQueue.wrapMethod(
 			"push",
 			FixedQueue.trimHead
 		);

 		FixedQueue.splice = FixedQueue.wrapMethod(
 			"splice",
 			FixedQueue.trimTail
 		);

 		FixedQueue.unshift = FixedQueue.wrapMethod(
 			"unshift",
 			FixedQueue.trimTail
 		);



 		// -------------------------------------------------- //
 		// -------------------------------------------------- //
 		// -------------------------------------------------- //
 		// -------------------------------------------------- //



 		// Create a fixed queue with some values.
 		var friends = FixedQueue( 3, [ "Sarah", "Kit" ] );

 		console.log( "Initial Values" );
 		console.log( friends );

 		// Add 2 items to the head.
 		friends.unshift( "Tricia", "Anna" );

 		console.log( "Add [ Tricia, Anna ] to head." );
 		console.log( friends );

 		// Add 2 items to the tail.
 		friends.push( "Kim", "Joanna" );

 		console.log( "Add [ Kim, Joanna ] to tail." );
 		console.log( friends );

 		// Add explicit value outside array.
 		friends[ 5 ] = "Nancy";

 		console.log( "Add [ Nancy ] out of bounds (explicitly)." );
 		console.log( friends );

 		// Add another item to the tail.
 		friends.push( "Becca" );

 		console.log( "Add [ Becca ] to tail." );
 		console.log( friends );


 	</script>

 </head>
 <body>
 	<!-- Left intentionally blank. -->
 </body>
 </html>
	<!DOCTYPE html>
	<html>
	<head>
	<title>Fixed-Length Queue Data Type In JavaScript</title>

	<script type="text/javascript">


	// Create a constructor for the fixed-length queue. This is
	// really more of a FACTORY than a construtor since an
	// entirely tangential object is returned.
	function FixedQueue( size, initialValues ){

	// If there are no initial arguments, default it to
	// an empty value so we can call the constructor in
	// a uniform way.
	initialValues = (initialValues \|\| []);

	// Create the fixed queue array value.
	var queue = Array.apply( null, initialValues );

	// Store the fixed size in the queue.
	queue.fixedSize = size;

	// Add the class methods to the queue. Some of these have
	// to override the native Array methods in order to make
	// sure the queue lenght is maintained.
	queue.push = FixedQueue.push;
	queue.splice = FixedQueue.splice;
	queue.unshift = FixedQueue.unshift;

	// Trim any initial excess from the queue.
	FixedQueue.trimTail.call( queue );

	// Return the new queue.
	return( queue );

	}


	// I trim the queue down to the appropriate size, removing
	// items from the beginning of the internal array.
	FixedQueue.trimHead = function(){

	// Check to see if any trimming needs to be performed.
	if (this.length <= this.fixedSize){

	// No trimming, return out.
	return;

	}

	// Trim whatever is beyond the fixed size.
	Array.prototype.splice.call(
	this,
	0,
	(this.length - this.fixedSize)
	);

	};


	// I trim the queue down to the appropriate size, removing
	// items from the end of the internal array.
	FixedQueue.trimTail = function(){

	// Check to see if any trimming needs to be performed.
	if (this.length <= this.fixedSize){

	// No trimming, return out.
	return;

	}

	// Trim whatever is beyond the fixed size.
	Array.prototype.splice.call(
	this,
	this.fixedSize,
	(this.length - this.fixedSize)
	);

	};


	// I synthesize wrapper methods that call the native Array
	// methods followed by a trimming method.
	FixedQueue.wrapMethod = function( methodName, trimMethod ){

	// Create a wrapper that calls the given method.
	var wrapper = function(){

	// Get the native Array method.
	var method = Array.prototype[ methodName ];

	// Call the native method first.
	var result = method.apply( this, arguments );

	// Trim the queue now that it's been augmented.
	trimMethod.call( this );

	// Return the original value.
	return( result );

	};

	// Return the wrapper method.
	return( wrapper );

	};


	// Wrap the native methods.
	FixedQueue.push = FixedQueue.wrapMethod(
	"push",
	FixedQueue.trimHead
	);

	FixedQueue.splice = FixedQueue.wrapMethod(
	"splice",
	FixedQueue.trimTail
	);

	FixedQueue.unshift = FixedQueue.wrapMethod(
	"unshift",
	FixedQueue.trimTail
	);



	// -------------------------------------------------- //
	// -------------------------------------------------- //
	// -------------------------------------------------- //
	// -------------------------------------------------- //



	// Create a fixed queue with some values.
	var friends = FixedQueue( 3, [ "Sarah", "Kit" ] );

	console.log( "Initial Values" );
	console.log( friends );

	// Add 2 items to the head.
	friends.unshift( "Tricia", "Anna" );

	console.log( "Add [ Tricia, Anna ] to head." );
	console.log( friends );

	// Add 2 items to the tail.
	friends.push( "Kim", "Joanna" );

	console.log( "Add [ Kim, Joanna ] to tail." );
	console.log( friends );

	// Add explicit value outside array.
	friends[ 5 ] = "Nancy";

	console.log( "Add [ Nancy ] out of bounds (explicitly)." );
	console.log( friends );

	// Add another item to the tail.
	friends.push( "Becca" );

	console.log( "Add [ Becca ] to tail." );
	console.log( friends );


	</script>

	</head>
	<body>
	<!-- Left intentionally blank. -->
	</body>
	</html>