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How To View Inception Through Code

dhirschl — Sat, 31 Jul 2010 15:28:30 +0000

If you have not seen Inception yet, I highly recommend doing so before reading this post.

**** SPOILERS AHEAD ****

Inception combines the best elements of movies in the Simulism genre; such as Dark City, eXistenZ, The Thirteenth Floor and The Maxtrix Trilogy; and creates an original, thought provoking film.

Watching the film from the standpoint of a programmer, I could not help seeing the similarities between the plot devices and basic programming concepts.

The Kick

The Kick is the concept they use in the movie to return to a dream level above the existing one. For example, if you perceive that you are falling in a dream, you have a tendency to wake up.

The Kick can be portrayed in programming in several different ways:

Recursion

public bool Dream()

{

     kick = CheckForKick();

     if(kick) return true;

     return Dream();

}

* CheckForKick() implementation has been omitted.

In this recursion example, each call to function Dream() will call another sub-Dream – until the CheckForKick() function returns true, which can occur however many levels deep.

Exception Bubble

public bool Dream()

        {

            try

            {

                try

                {

                    try

                    {

                        throw new DreamException("Receive Kick");

                    }

                    catch(DreamException dx)

                    {

                        throw dx;

                    }

                }

                catch(DreamException dx)

                {

                    throw dx;

                }

            }

            catch(DreamException dx)

            {

                // Handle Kick thrown 3 levels deep.

                Console.WriteLine(dx.Message);

            }

        }

In this Exception example, an exception is thrown within a nested try block. Rather than handling the exception at that level, it’s bubbled up until is (hopefully) handled gracefully.

Stack

This can best be represented by the following infographic, which I reconstructed to be a stack. Here is the original source.

A stack is one of the most fundamental data structures in computing. A stack operates in the following: items are added in a First-In, Last-Out (FIFO) manner. They are added via being “Pushed” onto the stack and removed via being “popped” from the Stack.

In the movie, each sub-dream is pushed onto the stack starting with reality. Our characters cannot return to a different dream level by popping the dream above off the stack.

Sedation

They use Sedation in the movie to prevent the dreamers from waking up any means other than “falling” on all dream levels above the first. At the first dream level, the only way to wake up is for the machine’s time to elapse.

Sedation in the movie can be explained through the use of Threading.

Threading

public void Inception()

{

     Machine mach = new Machine();

     Sedation sed = new Sedation();

     Thread machineThread = new Thread(new ThreadStart(mach.Start());

     Thread sedationThread = new Thread(new ThreadStart(sed.Sedate());

     try

     {

          sedationThread.Start();

          machineThread.Start();

          sedationThread.Join();

          machineThread.Join();

          ReturnToReality();

     }

     catch(Exception ex)

     {

          // Limbo ???

     }

}

* Machine implementation omitted. Sedation implementation below.

In this example, you can think of the sedation and starting the “dream machine” as being two separate threads – both induce unconsciousness, but in different ways.

The sedation occurs first as indicated by the sedationThread.Start(), followed by the machine start machineThread.Start(). The Sedation.Sedate() implementation may look like the following:

public void Sedate()

{

        Thread.Sleep(36000000); // 10 Hours

}

By calling join on the threads, the ReturnToReality() function will not get called until both the sedation wears off or the machine time elapses.

Limbo

Limbo is defined in the movie has a mental state where your mind doesn’t know if you are in reality or not. The only way out is to realize that Limbo is not reality.

I already hinted at how Limbo could be represented in code in the previous example – if there is an exception (i.e. death) during the running of the threads that does not allow them to complete. Also, Limbo could also be represented by the following:

Infinite Loop or Infinite Recursion

while(!IsAwareOfReality)

{

     CreateBuildings();

     CreateFromMemories();

     QuestionReality();

}

Most of the time that we are programming and find ourselves in an infinite loop, we are not aware of it until we start to question:

Why is this taking so long?
Why is my memory decreasing?
Why is my CPU pegged at 100%

Fortunately in programming there are ways to identify that we are in an infinite loop state.

If you are not aware of these conditions, you will stay there until your program runs out of memory or crashes (dies) or you realize you are in a loop (meet a condition) – by calling the QuestionReality() function.

Architect

The last item I will mention is the role of Architect. In the movie, Ariadne (Ellen Page) is responsible for creating the dreamscapes. This shares similarities with Software Architecture. As a software architect you responsible for knowing the systems (the main characters in movie) that you work with and to create the best solutions (e.g. Never Ending Staircase) to new problems that need to be solved (Inception). Being able to see the world around you as objects with state and behavior is a useful skill for both understanding Object Oriented Design/Programming; and as a Software Architect.

I was surprised how many people shared similar thoughts with comparing the movie with programming. If you enjoyed my post, please read their perspectives:

ASP.NET – Access To Path is Denied

dhirschl — Fri, 23 Jul 2010 02:29:11 +0000

If your ASP.NET program is attempting to read, write and/or delete a fie it can display the error “Access to Path … is Denied”. If this is the case, the directory may have the incorrect security settings.

Here are the steps to add the correct the user security settings on Windows Server 2003:

1. Find the folder or file that you are trying to access.
2. Right-click the folder
3. Select Properties
4. Click the Security tab
5. Click the Add button

6. Enter the user: \IIS_WPG
7. Click Check Names button

8. Click OK button
9. Verify user has correct permissions (Read/Write)

10. Click OK button

Other Windows operating systems (XP, Vista, 7) may require the user: \ASPNET to be added.

SharePoint 2010 Development Resources

dhirschl — Sat, 10 Jul 2010 16:50:13 +0000

Implementing SharePoint 2010 is an idea that is being thrown around at my place of employment right now. As a developer, there seems to be some significant differences between WSS 3.0/MOSS 2007 and SharePoint 2010 (SharePoint 2010 Sandbox Environment) and I wanted to make sure that my skills were updated for the latest release of SharePoint.

For everyone who is already developing or those who will start, I put together this list of resources that are available.

Videos

There are a few hands-on videos if you are a visual learner.

Books

If you prefer to learn from a book, there are many more resources available for SharePoint 2010 than there were previously for WSS 3.0 or MOSS 2007.

Pro SharePoint 2010 Solution Development: Combining .NET, SharePoint, and Office

Ed Hild and Chad Wach

SharePoint 2010 as a Development Platform

Joerg Krause, Martin Daring, Christian Langhirt, Bernd Pehlke, Alexander Sterff

SharePoint 2010 Development with Visual Studio 2010

Eric Carter, Boris Scholl, Peter Jausovec

Beginning SharePoint 2010 Development

Steve Fox

Professional SharePoint 2010 Development

Tom Rizzo, Reza Alirezaei, Jeff Fried, Paul Swider, Scot Hillier, Kenneth Schaefer

My Experience at Orlando Code Camp 2010

dhirschl — Fri, 09 Apr 2010 18:08:58 +0000

This post is long overdue but I thought I would share my experiences with attending my first code camp: Orlando Code Camp 2010.

Code Camp is something that always interested me, I thought it would be cool to experience some of the bleeding-edge technology and also receive some “free” training in the process.

If you are not aware of what a Code Camp is, it is an event where developers volunteer their time to present on several different topics – typically related to Microsoft products and technology and is sponsored by local technology companies.

Here is a breakdown of each session I attended:

Session 1

What to Know About WF 4.0

Presented by: Bayer White

I have just introduced myself to Windows Workflow Foundation (WF) since I have been teaching myself Windows SharePoint Services – so I thought I would get some exposure to what’s new in WF 4.0.

Take Away: WF 4.0 is significantly different from it’s predecessors, but there are some features that make it more productive: activities. A lot of the information was a bit over my head for being a novice at WF; however, once I get a good understanding of WF 3.0, I will migrate my skills to WF 4.0.

Links:
www.humanworkflow.net
www.flowfocus.com

Session 2

Building a Data Warehouse Using Sql Server 2008

Presented by Wes Dumey

The topic of Building a Data Warehouse is not new to me. I have taken graduate-level classes on the subject and actually built a Data Warehouse for a hospital as a team project – back in the days of Sql Server 2000. However, since taking this class, I have not had much exposure to the topic and the tools from Microsoft have changed significantly.

In the week previous to Orlando Code Camp I had attended several webinars by Pragmatic Works on Business Intelligence, so a lot of the information was review.

Take Away: Wes shared some ‘best practices’ that his firm adopted, such as storing the extracts after each step of the ETL process to verify the data.

Links:
Durable Impact Consulting
www.dayofdata.com

Session 3

Developing OLAP Solutions with SASS 2008

Presented by: Adam Jorgensen

One of the webinar sessions I missed with Pragmatic Works, was this very same presentation with Adam. So it was a treat to see Adam present this in person and demo the BI tools in Sql Server 2008.

Take Away: Since I have not used Sql Server 2008 BI Tools or even Sql Server 2005 BI Tools for that matter, I think there was an assumption that the audience had prior exposure. Adam frequently referred to the differences between 2005 and 2008 and also shared his pet peeve of naming dimensions with underscores.

Links:
Pragmatic Works

Session 4

Getting Started with WPF

Presented by: Shervin Shakibi

I haven’t had much exposure to WPF, so I thought I would check out this session for beginners. The presenter Shervin Shakibi is very comical and made the session pretty enjoyable.

Take Away:
From what I understand about WPF, is that it add additional functionality to creating Windows Forms and is primarily driven by XAML. It is possible to create web apps using WPF, but Shervin suggested to use Silverlight for that purpose.

Links:
www.computerways.com

Session 5

Silverlight Viewer for Reporting Services

Presented by: Jeremy Groves

This had to be the most unproductive session that I attended. It seemed as if the presenter was there against his will – the session only lasted about 10 minutes.

Take Away:
Silverlight Viewer for Reporting Services is actually a product by Perpetuumsoft and this session was nothing more than a marketing presentation to buy their product.

Links:
www.perpetuumsoft.com

Session 5.5

Stream It! Live + HD + Silverlight

Presented by Kevin Rohling

Since I had some time to kill, I went to this session since it was the location for Session 6.

Take Away:
Kevin Rohling made note of a video (that I had never heard of before) that is available in the public domain: Big Buck Bunny.

Links:
www.perpetuumsoft.com

Session 6

Dissecting a Real-World Silverlight 4 Application

David Silverlight

I really wanted to see Silverlight development in action and I was provided this opportunity in David Silverlight’s session.

Note: I have to admit I once thought that Silverlight was named after him.

Take Away:
David presented a User Group Website Starter Kit software package that was developed using Silverlight, and is available to download via CodePlex.

Links:
Silverlight User Group Website Starter Kit
www.perpetuumsoft.com

Overall, I was exposed to a lot of new technology at Orlando Code Camp. I look forward to attending Tampa Code Camp later this year.

More Blogs about Orlando Code Camp:

How To Master a Programming Language V

dhirschl — Thu, 21 Jan 2010 16:52:02 +0000

For my final post of the series How to Master a Programming Language, I want to make note how you can take the programming knowledge that you have gained so far and apply it to something bigger.

Learn a Framework

Now that you have worked through the language and applied it to solving problems, how do you go about solving bigger problems or accomplishing large project? Answer: Use a framework.

If you are unfamiliar with frameworks, they allow you extend the API of your language beyond the base software library. All frameworks are not created equal, a given language may have several frameworks available – each one used for solving a different problem.

Java

C#/VB.NET

PHP

Comparison of PHP Frameworks

Ruby

Python

Web Frameworks for Python

Start a Project For Yourself

You will only start to appreciate a programming language and its framework when you start working with it to create something of value.

If you already have an idea in mind – great! Run with this idea and start using the tools that you have learned.

If you are stuck trying to figure out a potential project – talk to people. People always speak of ideas, but few people actually follow up. Identify phrases such as “I wish there was…”:

“… a website that would do this…”
“… an easier way of doing this…”

Still stuck? Here is a list of resources to help you in the right direction:

I am always looking for suggestions from my readers. If there are any frameworks or programming project websites that I should add, please feel free to share.

How To Master a Programming Language IV

dhirschl — Sun, 17 Jan 2010 13:49:19 +0000

At this point you should competent in the programming language that you have chosen (Part III) — you should be able to recognize basic code constructs (such as types, loops, and variable assignment). You should also be able to recognize syntax and semantic errors in your code and be able to debug them.

The next step to mastering a programming language involves “flexing your code muscle.” What I mean by that is to start using the knowledge you have acquired through reading books and tutorials and apply it to solve problems.

Flexing Your Code Muscle

Basic Exercises

I came across a website a while ago that lists 15 Exercises for Learning a new Programming Language by Prashant N Mhatre.

The purpose of these exercises is to learn how to perform basic mathematical and commonly used code procedures in your language of choice.

Topics Covered by 15 Exercises

Program Interruption
Mathematical Problem Solving
Sorting a list
If Statements
Loop Mechanisms
Exception Handling
Input and Output
File Operations
Date Operations
String Searching and Replacement
Inserting into List
Language specific operations

Most of these topics can be applied to mostly any 4th generation programming language.

Problem Solving

I have previously listed several websites with programming puzzles to allow practice your skills: Get Hired By Solving Programming Puzzles.

Out of all the sites with programming puzzles, I would have to recommend Project Euler.

There are over 270 problems (as of 1/15/2009) with new problems being added every month. The problems found on Project Euler are geared towards students and are not meant to be too extensive. The problems can be solved using any programming language.

Setup an account with Project Euler and start solving problems. If you are finding the problems too difficult, Project Euler has the option to sort the problems in ascending difficulty.

If you continue to have difficulty, read about the mathematical concept you are solving for (e.g. Fibonacci, Greatest Common Divisor, etc.) on a site like wikipedia and think about how you would solve the problem without a computer. Then think about how you would apply that technique using a programming language.

Practice, Practice, Practice

“Practice isn’t the thing you do once you’re good. It’s the thing you do that makes you good.” – Malcolm Gladwell

This post is all about practice, which is also the mantra of this blog. If you want to become a master at programming, this is one step that you cannot leave out.

How do you practice using your programming skills?

How To Master a Programming Language III

dhirschl — Fri, 15 Jan 2010 00:48:50 +0000

Now that you are comfortable working within your desired editor or IDE (Part II) – you can start to focus on learning the programming language syntax.

To learn a programming language you can read a variety of different books or read through online tutorials and how-to’s. Since everyone approaches learning differently, I will leave the decision up to you.

Programming Books

If you learn best by reading a book, I suggest choosing a tutorial book that walks you through learning the language rather than a reference book (at first).

A tutorial books is the better choice because it can be read cover-to-cover and it encourages the reader to work through problems, examples and case studies.

I am a big fan of the Deitel & Deitel books for this reason.

C++ How to Program

Paul J. Deitel and Harvey M. Deitel

Visual C# 2008 How to Program

Paul J. Deitel

Java How to Program

Paul J. Deitel and Harvey M. Deitel

I’ve also mentioned before that I am also recommend the Head First series of books because they teach programming concepts in a practical way without technical jargon.

Head First HTML with CSS & XHTML

Elisabeth Freeman and Eric Freeman

Head First PHP & MySQL

Lynn Beighley and Michael Morrison

You can also find free e-books (in pdf format) that teach programming languages. I recommend How to Think Like a Computer Scientist by Allen B. Downey for learning the Python language.

Programming Tutorials and How-To’s

If you learn better by online tutorial or if you want to supplement your books – there are many websites that offer programming language tutorials.

Again, I recommend finding an online tutorial that walks you through learning the syntax of the language.

List of Tutorials

Ruby Tutorial (via RubyLearning.com)
C/C++ Tutorial (via CProgramming.com)
Free Programming Tutorials (via freeprogrammingresources.com)
Programming Tutorials (via tutorialguide.net)
Misc. Tutorials (via ProgrammingTutorials.com)
Web Building Tutorials (via w3schools.com)

A Grasp of the Language

After you have read through a book or tutorial, you should have a good grasp of the language syntax – but you are far from being a master of the language at this point.

Keep in mind that you don’t need to memorize every little detail about the language, but you should be familiar. You should know how to reference the language API, a useful reference is gotAPI.com which has a comprehensive listing of many programming languages.

If you know of any good tutorial websites or books, please share in the comments.

How To Master a Programming Language II

dhirschl — Mon, 11 Jan 2010 12:20:39 +0000

So you’ve chosen a programming language that you want to learn, where do you start?

Learn the Environment

Depending on the type of language that you have chosen (interpreted vs. compiled) there may be several options available to you in choosing an editor or Integrated Development Environment (IDE).

Editors

Most programming languages can be written in your editor of choice. The preferred editor will include at a minimum syntax highlighting.

Some Text Editors Supporting Syntax Highlighting

VIM (All Platforms)
Notepad++ (Windows)
TextMate (OS X)

Integrated Development Environment

If you want a full-featured editor, you may consider choosing an Integrated Development Environment (IDE). IDEs will provide an interactive debugger, advanced syntax checking, integration with software configuration management (SCM) systems, etc. Sometimes learning all the features of the IDE is just a big of a task as learning a language.

Some Integrated Development Environments

Visual Studio (C/C++, C#, Visual Basic, Others via Install)
Eclipse (Java, Others via plug-ins)
Netbeans (Java, PHP, Ruby, etc.)

Resolve Dependencies

Depending on the language you are learning, there may be additional dependencies that your development environment requires. Whether you are using an IDE or text editor you need to have the language interpreter or compiler installed (or else you won’t get very far).

Also, if you are developing web applications, you will need to have a web server or web application server installed and configured.

Most IDEs will resolve these dependencies for you – however, you may also consider using a all-in-one local server environment.

MAMP
XAMPP

Basic Programming Tasks

After your programming environment is setup correctly (you may need to make some additional tweaks along the way), work through a “Hello World!” problem in the language of your choice. Make sure you can do the following:

Check for Errors in Syntax
Compile via GUI and Command Line (if your language supports this)
Run your Program

At this point you should have basic command of your environment. As you work with it and get deeper into your language, you will become more familiar with the different features and options available to you.

How To Master a Programming Language

dhirschl — Mon, 11 Jan 2010 02:00:02 +0000

With the start of a new year, as a programmer have you made a resolution or goal to learn a new programming language?

For the next few days, I will be writing a series of posts titled How to Master a Programming Language, where I will be walking you through the steps that you need to take to learn the ins and outs of a programming language.

If you really want to master a new programming language, you have to do more than just read these posts — you need to take action!

Think about what you have done previously when learning a language. Is there anything you have done differently that has helped you learn a language? Please feel free to share your experiences in the comments.

Read the series of posts here:

9 Useful Websites for Thematic Child Theme Development

dhirschl — Mon, 23 Nov 2009 10:00:28 +0000

You’ve may have noticed a design change here at RepeatGeek, if you’ve visited before. I have been exploring different WordPress frameworks to build my website around and I finally decided upon Thematic.

My decision to go with Thematic was that it is extensible, stable, SEO optimized, easily configurable and most importantly FREE.

In developing my child theme, I thought I would share some resources that I found useful.