Sometimes you have to fail hard

This was a post I wrote in the middle of 2013 but never published. I wanted to share this since it’s a common story across all technologies and developers of all skill levels. Sometimes things really just don’t work. As a post-script, I did come back to this project and had a lot of success. When in doubt, let time figure it out :)

For the last couple of weeks, I’ve been trying my hand at the node.js ecosystem. I had an app idea but I wanted to make sure I chose tech stacks wisely. There’s no better way to get familiar with different stacks than to get your hands dirty and try them all, so that’s what I did.

Sometimes when you start with a new language or platform things come easy, you can blaze a burning trail writing great software. You’re like an extension of the computer, everything … Read more

wcf Request Entity Too Large

I ran into a stupid issue today with WCF request entity too large errors. If you’re sure your bindings are set properly on both the server and client, make sure to double check that the service name and contract’s are set properly in the server.

My issue was that I had at some point refactored the namespaces where my service implementations were, and didn’t update the web.config. For the longest time things continued to work, but once I reached the default max limit (even though I had a binding that set the limits much higher), I got the 413 errors.

So where I had this:

<service name="Foo.Bar.Service">
	<endpoint address="" binding="basicHttpBinding" bindingConfiguration="LargeHttpBinding" contract="Foo.Bar.v1.Service.IService"/>

I needed

<service name="Foo.Bar.Implementation.Service">
	<endpoint address="" binding="basicHttpBinding" bindingConfiguration="LargeHttpBinding" contract="Foo.Bar.v1.Service.IService"/>

How WCF managed to work when the service name was pointing to a non-existent class, I have no idea. But it did.… Read more

Short and sweet powershell prompt with posh-git

My company has fully switched to git and it’s been great. Most people at work use SourceTree as a gui to manage their git workflow, some use only command line, and I use a mixture of posh-git in powershell with tortoise git when I need to visualize things.

Posh-git, if you load the example from your profile, will set the default prompt to be the current path. If you go into a git directory it’ll also add the git status. Awesome. But if you are frequently in directories that are 10+ levels deep, suddenly your prompt is just obscenely long.

For example, this is pretty useless right?

2014-07-09 11_53_20-

Obviously it’s a fictitious path, but sometimes you run into them, and it’d be nice to optionally shorten that up.

It’s easy to define a shortPwd function and expose a global “MAX_PATH” variable that can be reset.


function ShortPwd
    … Read more
Multiple SignalR clients and ASMX service calls from the same application

I was writing a test application to simulate what multiple signalR clients to a server would act like. The clients were triggered by the server and then would initiate a sequence of asmx web service calls back to the server using a legacy web service. This way I was using signalR as a triggering mechanism and not as a data transport. For my purpose this worked out great.

I had coupled the asmx calling code into a test class for a signalR client, so each class was responsible for its internal signalR connection as well as its outgoing asmx calls. When I had one class everything worked great. But the moment I had two classes running (i.e 2 signalR connections and 2+ asmx connections) everything locked up. I couldn’t figure out what was going on. The signalR clients had connected but all the asmx calls stopped making it through, and … Read more

Constraint based sudoku solver

A few weekends ago I decided to give solving Sudoku a try. In case you aren’t familiar with Sudoku, here is what an unsolved board looks like

from wikipedia

And here is a solved one

from wikipedia

Sudoku, of size 3 is pretty easy. Make a snapshot of the board, pick a random open cell, find out what its available possibilities are and set it to a value. To figure out it’s possibilities you need get the cells “group”. This means all the values of the 3×3 cell it’s in, as well as all the values of the row that it’s in and the columns that it’s in.

Based on what is available, you can choose a number that isn’t taken, plop it in down, and then recursively repeat. If nothing is available, and the board isn’t empty, you messed up and the recursion will backtrack.

Let’s get solvin’

Some … Read more

Creating futures

Futures (and promises) are a fun and useful design pattern in that they help encapsulate asynchronous work into composable objects. That and they help hide away the actual asynchronous execution implementation. It doesn’t matter if the future is finally resolved on the threadpool, in a new thread, or in an event loop (like nodejs).

Asynchronous work wrapped in futures has garnered a lot of attention in the javascript world since they alleviate the heavy use of nested callbacks to return a final result. But futures aren’t limited to just javascript, the C# async keyword is a form of a future, Java has a futures class, and a lot of other languages have the ability to use futures.

In order to to demystify the concept of Futures lets build own version. Futures aren’t hard to implement, even when you have a language that doesn’t have them built in (or if you … Read more

Instagram viewer with node and angular

I have an artist buddy who is working on an art installation and asked me if there was a way to display a realtime view of an instagram hashtag feed on a projector.

Unfortunately there isn’t anything right out of the box available, but I offered to write him a quick app that he could fire up that would give him what he wanted.

For the impatient, full source is available at my github.

One way to do this would be to hook into the instagram realtime API. Using the realtime API you subscribe to tags or users via their API and supply a url callback. Instagram will then callback to your endpoint with an HTTP GET, validate that you actually did request (via a handshake response), and then post to your endpoint whenever something on that subscription has changed. What it won’t do is actually give you … Read more

Building a prefix trie

Prefix trie‘s are cool data structures that let you compress a dictionary of words based on their shared prefix. If you think about it, this makes a lot of sense. Why store abs, abbr, and abysmal when you only need to store a,b,b,r,s,y,s,m,a,l. Only storing what you have to (based on prefix) in this example gives you a 70% compression ratio! Not too bad, and it would only get better the more words you added.

The classical way of dealing with prefix tries is to store the suffixes using a map, but for fun I tried something different and used a list.


The main data structure I had was like this

type Key a = [a]

data Trie key = Node (Maybe key) [Trie key] Bool deriving (Show, Eq, Read)

So a trie is really just a node that has a list of other tries … Read more

Avoiding nulls with expression trees

I’ve blogged about this subject before, but I REALLY hate null refs. This is one of the reasons I love F# and other functional languages, null ref’s almost never happen. But, in the real world I work as a C# dev and have to live with C#’s… nuisances.

In the other post, a big problem with the dynamic proxy was that it only worked with virtual methods, so it wasn’t really all that practical. This time around I decided to try a different route and leverage expression tree’s to actually build out the if checks automatically.

For the impatient, full source available at my github and the library is available on nuget


Let me demonstrate the final usage first. If all of users properties and methods return null, executing this whole chain would fail starting at the null result of GetSchool(). But, by using the Option static … Read more

Strongly typed powershell csv parser

Somehow I missed the powershell boat. I’ve been a .NET developer for years and I trudged through using the boring old cmd terminal, frequently mumbling about how much I missed zsh. But something snapped and I decided to really dive into powershell and learn why those who use it really love the hell out of it. After realizing that the reason everyone loves it is because everything is strongly typed and you can use .NET in your shell I was totally sold.

My first forays into powershell included customizing the shell environment. First I got conemu and made it look nice and pretty. Next was to get an ls highlighting module, since I love that about unix shells.

I set up a few fun aliases in my profile and felt ready to conquer the world! My next experiment was to try and create an actual binary cmdlet. I figured, what … Read more