Random bits of foo

Failings of the Unix Commodity

2012-01-19T11:08:00.000-08:00

Imagine if you will a city with an array of transportation systems. The most popular transportation system is a personal helicopter. A home can have dozens of automated helicopters, each built to go fly to a single place and back. Very little knowledge is needed to operate these helicopters and traveling with them is rather convenient: You don't have to wait for traffic lights or wind around with a road. You just hop in, the helicopter takes the absolutely most direct route to your destination, and you hop out.

People have grown quite accustomed to having large garages in this city where they keep little armadas of these specialized aircraft; one for going to the supermarket, one for going to the mall, one for going to work, one for going to school, one for going to night clubs, one to cruise around town, and so on. Hop in, push the "Start" button and you're on your way!

In order to keep selling these helicopters to consumers, manufacturers have been adding luxurious features. It began with cup holders and grew into hot tubs, projector screens, and all other sorts of amenities to make the flight more pleasant. While these luxuries do add weight that slows the helicopters down, people don't really notice because of all the fun they're having.

Because these helicopters blindly take the most direct routes to their destinations, crashes are not unheard of. Some manufacturers try to avoid crashes between two of their own helicopters but that doesn't really do much for the overall aviation safety.

Earlier-on in their history, these helicopters were infamous for their propensity to have mid-air collisions, landing mishaps, and the like. In spite of all the damage this incoherent method of transportation has caused, you can't argue with the billions of dollars the flying hot tubs have raked in.

While it is true that these helicopters can only travel to certain places, this is largely mitigated by the fact that people are willing to make many varieties of helicopters. Most helicopter riders only really care to go to the most popular shopping centers and movie theaters anyway so they're quite content with the selection.

The other major mode of transportation is the local subway system. This series of subterranean tracks is dark, damp and noisy. It's inconvenient -- requiring you to know a schedule and how trains connect in order to really get anywhere. It usually involves a lot of indirection as you connect to various stations and hop between different lines to get to your destination.

Those who prefer the subway system are proud of how low their expenses are and how few people actually get hurt by their transit system. They have experts dedicated to maintaining and fine-tuning the whole transit system to make sure that every train arrives on time with as few surprises as possible.

Subway workers and users get along well. They have a thriving subculture in their subway. They all know each other and were always eager to exchange ideas about anything but especially about how they could make their subway better.

Many of the riders are also share-holders in the subway. They take the money they save from having such an inexpensive transit system and invest it into expanding and refining it. As a result, there is no part of the city that is more than a mile from the nearest subway station. While walking to the subway station is a little bit of work, it is manageable and subway drivers tend to be fit and capable of the trek.

With a subway pass (that costs less than a tenth of the insurance premiums that most pay for their helicopters) and a good understanding of the subway system, subway passengers can get anywhere they'd like to go. They see parts of the city that may be beneath the notice of helicopter riders because nobody makes aircraft that fly there. These subway riders are totally content to trade some convenience for this kind of freedom; there are no prescribed ways or places to travel. There is only a system that helps you get anywhere.

Helicopter riders feel like fish out of water when they enter the subway. They enter the train and start looking for the massaging recliner seats but they find only stiff benches. They get confused by the unspoken need to pay attention and know whether or not a stop is at the destination. They are absolutely horrified about the idea of having to walk anywhere -- thinking that when the vehicle stops, the journey should be totally over. When buried in a tunnel, they feel incapable of knowing where they are or what direction they want to be going. In fact, they feel annoyed that they have to even know anything about direction.

When I was still in diapers, there were two kinds of computers around: The home desktop and the mainframe. Home desktops were like a garage full of the Helicopters above: Emphasizing personal convenience and mass-marketability at the cost of stability and long-term maintainability. Mainframes were like the Subway described above: Sacrificing personal convenience and ease-of-use in exchange for having a robust, reliable, versatile system that can service the needs of many people at once.

I know I'm going to get crap if I don't mention Linux so...

As the years went by in this city, helicopter manufacturers got adventurous. They tried to emulate admirable traits of the subway system; sometimes consciously, sometimes not. They started making helicopters that could fly to multiple destinations. They started making hybrid airplane-helicopter craft that could take you greater distances than just a helicopter could. They introduced parachutes to keep helicopters from crashing into the ground in a massive conflagration of doom, and they started teaching riders to jump out of one helicopter and into another in a highly dangerous attempt at getting people places faster without having to buy more helicopters.

Meanwhile, others who admired the solid engineering of the subway system tried to emulate its strengths. A group of volunteers paved an expansive road system on the ground that roughly resembled the subway tunnels beneath them. Other volunteers built custom cars to drive on this road that had some of the conveniences you find in personal helicopters.

These automobile drivers included crazy hippies that believed that asphalt was implicitly morally superior to flying as well as some entrepreneurs who hoped there would be a rising car market like there had been a helicopter market. Some still just liked the penguin logo that was painted onto the cars.

While driver neglect could cause crashes on these roads and they were still more common than in the subway, the consequences of these crashes weren't quite as catastrophic as the airborne equivalents and so it was generally believed to be better.

This is a story that many are familiar with. But there's actually a lot more to it than that. Years before the automobile was introduced, there emerged another subway imitation in town.

Some entrepreneurial souls looked at the great efficiency and usefulness of the subway and decided to try making rail travel a tradable commodity. They prefabricated railways that could be flown in and dropped on top of a neighborhood for an instant railway transit system. This process was naturally expensive so only the wealthiest districts could afford such a thing.

The enormous template of rail tried hard to look like the layout of the subway system. But building such a system in such a different circumstance is hard. When transporting this massive pretzel of track, it would often bend and warp under its own weight and had to be reshaped to fit the terrain. After the track was finally set in place, it usually didn't resemble the subway it was intended to emulate.

Three major companies rose as providers of trolley networks. Each had their own ideas as to what a track system should look like and how the trolley cars should behave. Each track would be just similar enough that a passenger could make a few safe assumptions about the schedules and directions of certain lines. And each would have its own "gotchas" that made expertise in one neighborhood's track not fully transferable to another.

The lack of standardization between all trolley systems made it incredibly difficult for some to navigate -- even those who had grown accustomed to the subway system were not quite at home on this surface railway.

Because the companies that made these tracks were more interested in manufacturing efficiency than in usage efficiency, trolleys were eventually written off as a cute anachronism rather than a real transit system. The purported savings of using such a system simply weren't there. What's more, because these trolleys purported themselves to be the same as the subway system, whatever bad reputation they'd accrued was shared with the subways.

Those who had sunk the great amounts of money into buying trolley systems were stuck with them and tried to make do with what they had but no new buyers were lining up.

Trolley companies eventually got to the point where they made all their money selling repair and maintenance services to people who'd previously purchased trolley systems from them.

Some tired to add propeller blades to their trolley cars; thinking this could attract some helicopter-style revenue. Other companies tried making their cars bigger or faster to see if that would attract neighborhoods to their wares.

In spite of all their efforts, the trolley companies weren't getting the kind of money they wanted. Their attempts at mutating with market demands only made whatever rail templates they did sell even less cohesive than before.

One trolley manufacturer decided to shift efforts toward building accessories for helicopters. Another transformed its trolleys into industrial freight trains. The last fumbled around for a while until the penguin cars showed up. They eagerly jumped on the bandwagon and have been trying to transform their own track into paved roads since. As soon as they saw the cars weren't just a fad, they started pulling parts out of their disheveled trolley cars and plugging them into the automobiles, hoping more than anything that they could turn it into a solid business plan.

This last company still has lingering segments of track with disheveled cars sputtering about it. This slow energy hog of a transit system is a glorious testament of the hubris of the trolley industry which presumed they could prefabricate the emergent brilliance of a peer-reviewed, actively used, actively maintained transit system.

Some took this lesson from the trolley industry as evidence that rail travel was all together flawed or that the mistakes of the trolley were the mistakes of the subway as well. Some even believed that the pitfalls of the trolley model were a problem with all non-aeronautic travel --- making it easy to dismiss the cars and their pavement when those started cropping up.

Today, the trolley is one of the more clumsy, unreliable forms of transportation there is. Even the messy helicopter industry has managed to fumble their way into some best practices that mitigate their system's shortcomings. As helicopters grow to more closely resemble the subway system beneath them, they brag about how novel and illustrious their inventions are and they mock the rails that they see beneath them.

Their mockery is not entirely unfounded. If your only exposure to computing systems were the home desktop and the commercial Unix system, it makes perfect sense why you would prefer your squadron of helicopters.

jQuery how I love you.

2012-01-18T08:34:00.000-08:00

So I had a problem today where I needed to be able to tell if a JavaScript object was empty. I spent 10 minuets Googleing for a consice soluction then I went to jQuery util page on a whim and the answer was there.

http://api.jquery.com/jQuery.isEmptyObject/

With just one call the library will tell me if it has data. Thanks to the people that build such cool tools for me to use.

Benchmarking arithmetic

2012-01-13T12:51:00.000-08:00

Got curious so I decided to see how quickly and accurately some arithmetic gets done in various environments. Results below.

[ishpeck@slcatedjamu ~]$ time dc -e "16384d^p"
113837518811535904250072068341232590877598871955010488951192642300792\
621302625312821980719831387362324936714246794526258573039676337010858\
828763430793585922853616976807646165532533059489556150449708988141578\
442943112023447213983043116092849446398990980402342632274314814328953\
404819192156219054837263740293206244418473178404516135133213244063518\
784562296023799090475839668510215390134010117698262576769574042814029\
529033278052184274508131740701273566100706819850632337113494857562098\
320151217292158833266370707127916108421901433177514694034750917722728
... ....
218238270074739736264157780272832032578594361150434678340392480113080\
089703735801591153586235927851796939292373259062814173277075113674401\
829043044144045490928371875112748010711233174142910835089303346849145\
895484745236306027347877637526426501080516036812222087305078640639225\
541848209795509140539016236258676383295890570846220185368800472374864\
023572119859359115185919085597104610288583655001397080304511835993974\
191673243089264458895016889710034575213135566915400700972672256581021\
999134594756634350940758242683390117111624193719460587302044176159214\
609746781781933047509937334480699072619539011846151062186574802048674\
92382202923258637344388123757033376532121188827136

real 0m1.167s
user 0m0.283s
sys 0m0.003s

dc surprised me with its slowness until I realized it was throwing those backslashes in there. That can eat up some time.

[ishpeck@slcatedjamu ~]$ time python -c "print 16384 ** 16384"
1138375188115359042500720683412325908775988719550104889511926423007926213026253128219807198313873623249367142467945262585730396763370108588287634307935859228536169768076461655325330594895561504497089881415784429431120234472139830431160928494463989909804023426322743148143289534048191921562190548372637402932062444184731784045161351332132440635187845622960237990904758396685102153901340101176982625767695740428140295290332780521842745081317407012735661007068198506323371134948575620983201512172921588332663707071279161084219014331775146940347509177227281385333933210897869224188603686168680892745382927717262582865116798735382574696365796311299351046728260094290719606736072012259117111400667629363151930588541659099143747134721613089069740776235687657534765557725361993289329394049820885278902800491606809630123223601804037635379024208423418856532333180705506732367579643586252181430162147604245508970283612154605179099342622822975114534462339240221466716903857275803280366341678962977346051289393798425922859136969165217554566247811263669128403448140287396494805411846462566580026934215636853835525602451004242548897751439534340759663617153864418706583169642432738589331305934295186834298433853228606541975022545265261045793253180106547809428350799194427853647105017781506127477182293624210259930919849611849204841346064260162960557828534199134070897721151924
... ...
703704366990068353216089737426366069381491347684599380093222610835917961800770781409200926729603012036399122612354223297965849193568220166221823827007473973626415778027283203257859436115043467834039248011308008970373580159115358623592785179693929237325906281417327707511367440182904304414404549092837187511274801071123317414291083508930334684914589548474523630602734787763752642650108051603681222208730507864063922554184820979550914053901623625867638329589057084622018536880047237486402357211985935911518591908559710461028858365500139708030451183599397419167324308926445889501688971003457521313556691540070097267225658102199913459475663435094075824268339011711162419371946058730204417615921460974678178193304750993733448069907261953901184615106218657480204867492382202923258637344388123757033376532121188827136

real 0m0.789s
user 0m0.203s
sys 0m0.010s

Intrepid old Python has some nice optimization to help eek out those fractions of a second.

[ishpeck@slcatedjamu ~]$ time clisp -x "(expt 16384 16384)"
i i i i i i i ooooo o ooooooo ooooo ooooo
I I I I I I I 8 8 8 8 8 o 8 8
I \ `+' / I 8 8 8 8 8 8
\ `-+-' / 8 8 8 ooooo 8oooo
`-__|__-' 8 8 8 8 8
| 8 o 8 8 o 8 8
------+------ ooooo 8oooooo ooo8ooo ooooo 8

Welcome to GNU CLISP 2.49 (2010-07-07)

Copyright (c) Bruno Haible, Michael Stoll 1992, 1993
Copyright (c) Bruno Haible, Marcus Daniels 1994-1997
Copyright (c) Bruno Haible, Pierpaolo Bernardi, Sam Steingold 1998
Copyright (c) Bruno Haible, Sam Steingold 1999-2000
Copyright (c) Sam Steingold, Bruno Haible 2001-2010

Type :h and hit Enter for context help.

1138375188115359042500720683412325908775988719550104889511926423007926213026253128219807198313873623249367142467945262585730396763370108588287634307935859228536169768076461655325330594895561504497089881415784429431120234472139830431160928494463989909804023426322743148143289534048191921562190548372637402932062444184731784045161351332132440635187845622960237990904758396685102153901340101176982625767
... ...
7414291083508930334684914589548474523630602734787763752642650108051603681222208730507864063922554184820979550914053901623625867638329589057084622018536880047237486402357211985935911518591908559710461028858365500139708030451183599397419167324308926445889501688971003457521313556691540070097267225658102199913459475663435094075824268339011711162419371946058730204417615921460974678178193304750993733448069907261953901184615106218657480204867492382202923258637344388123757033376532121188827136
Bye.

real 0m1.262s
user 0m0.393s
sys 0m0.007s

It surprised me how much slower Common was here. Doesn't help that it clutters the display with all that junk, either.

[ishpeck@slcatedjamu random_scripts]$ time csharp -e "Console.WriteLine(Math.Pow(16384, 16384));"
Infinity

real 0m0.282s
user 0m0.257s
sys 0m0.033s

I don't know what I did wrong here... I mean, besides trusting a statically typed language to know what to do with so huge a number.

[ishpeck@slcatedjamu ~]$ time newlisp -e "(pow 16384 16384)"
inf

real 0m0.003s
user 0m0.000s
sys 0m0.000s

LAWL! Infinity!

[ishpeck@slcatedjamu ~]$ time echo "16384 ^ 16384" | ghci
GHCi, version 7.0.3: http://www.haskell.org/ghc/ :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package ffi-1.0 ... linking ... done.
Prelude> 11383751881153590425007206834123259087759887195501048895119264230079262130262531282198071983138736232493671424679452625857303967633701085882876343079358592285361697680764616553253305948955615044970898814157844294311202344721398304311609284944639899098040234263227431481432895340481919215621905483726374029320624441847317840451613513321324406351878456229602379909047583966851021539013401011769826257676957404281402952903327805218427450813174070127356610070681985063233711349485756209832015121729215883326637070712791610842190143317751469403475091772272813853339332108978692241886036861686808927453829277172625828651167987353825746963657963112993510467282600942907196067360720122591171114006676293631519305885416590991437471347216130890697407762356876575347655577253619932893293940498208852789028004916068096301232236018040376353790242084234188565323331807055067323675796435862521814301621476042455089702836121546051790993426228229751145344623392402214667169038572758032803663416789629773460512893937984259228591369691652175545662478112636691284034481402873964948054118464625665800269342156368538355256024510042425488977514395343407596636171538644187065831696424327385893313059342951868342984338532286065419750225452652610457932531801065478094283507991944278536471050177815
......
1800770781409200926729603012036399122612354223297965849193568220166221823827007473973626415778027283203257859436115043467834039248011308008970373580159115358623592785179693929237325906281417327707511367440182904304414404549092837187511274801071123317414291083508930334684914589548474523630602734787763752642650108051603681222208730507864063922554184820979550914053901623625867638329589057084622018536880047237486402357211985935911518591908559710461028858365500139708030451183599397419167324308926445889501688971003457521313556691540070097267225658102199913459475663435094075824268339011711162419371946058730204417615921460974678178193304750993733448069907261953901184615106218657480204867492382202923258637344388123757033376532121188827136
Prelude> Leaving GHCi.

real 0m1.060s
user 0m0.250s
sys 0m0.173s

And for more LOL's!

[ishpeck@slcatedjamu ~]$ time lynx -dump http://www.wolframalpha.com/input/?i=16384%5E16384
#[1]Wolfram|Alpha

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+ [11]Wolfram Science
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+ [13]More

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Computing
Computing...
__________________________________________________________________

Input:

16384^16384
[23]Save as image [24]Copyable plaintext [25]Mathematica form
__________________________________________________________________
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Decimal approximation:

* [26]More digits

[27]1.13837518811535904250072068341232590877598871955010... 10^69049
__________________________________________________________________
__________________________________________________________________

Power of 10 representation:

10^(10^4.839157747319649)
__________________________________________________________________
__________________________________________________________________

Number length:

69050 decimal digits
__________________________________________________________________
__________________________________________________________________

Last few digits:

...1188827136
__________________________________________________________________

[28]Computed by Wolfram MathematicaDownload as: PDFLive Mathematica

... ...

real 0m1.025s
user 0m0.017s
sys 0m0.010s

Of course, this is all very far from scientific but it was amusing to try. I've noticed that clisp tends to out-perform Python on smaller numbers (I assume because Python's cache is helpind it out when there's a lot of repitition). Nobody who actually _tried_ to compute the desired value botched anything up (the way Python is wont to in some arithmetic situations).

I know Haskell tended to be much faster if you subtracted start-up time (which this test does not).

Wrote my first jquery plugin it strips out html for an input field

2011-12-07T13:19:00.001-08:00

I needed a way to remove up html from my input from the users.  This is my first attempt at it.
(function ($) {
 
    $.fn.safeVal = function () {
        var value = $(this).val();
        var ret = $('<div>').html(value).text();
        return ret;
    };
})(jQuery);

My Rules for Development

2011-08-04T13:34:00.000-07:00

If you think you need a region you really need a new class.
If you are using a for loop in c# there is something wrong with your code.
If you are using a foreach fix you code so you don't need it.
If you think you want to use exceptions to control flow stop now and go to your room and think about what damage you may do.
If you don't write a unit test it's not done.

Some Fun With Linq.

2011-05-18T13:27:00.000-07:00

A friend of mine was asking me how I search through dictionary that contain lists of objects with Linq. After I chatted with him for a bit. I realized I don't do that. I have one huge list that I parse out with linq. It makes my life easier. Here is a code example of what I would use.

        public class section
        {
            public string Group { get; set; }
            public string Order { get; set; }
            public string Section { get; set; }
            public string Title { get; set; }
        }
 
        static void Main(string[] args)
        {
            var sec = new List<section>();
            sec.Add(new section { Group = "1", Order = "1", Section = "1.1", Title = "one one" });           
            sec.Add(new section { Group = "1", Order = "3", Section = "1.3", Title = "one three" });
            sec.Add(new section { Group = "1", Order = "2", Section = "1.2", Title = "one two" });
            sec.Add(new section { Group = "2", Order = "1", Section = "2.1", Title = "two one" });
            sec.Add(new section { Group = "2", Order = "2", Section = "2.2", Title = "two two" });
            sec.Add(new section { Group = "3", Order = "1", Section = "3.1", Title = "three one" });
 
            //creates a diction with all the sections in order grouped by group.
            var jmp = sec.OrderBy(j => j.Order).GroupBy(c => c.Group).ToDictionary(c => c.Key, d => d.ToList());
            //gets one section form a section
            var wantedSection = sec.FirstOrDefault(c => c.Section == "2.2");  //return null if no iteem found
            //gets one section in the order you set in order
            var sectionOne = sec.Where(c => c.Group == "1").OrderBy(c => c.Order).ToList();                        
        }

I found this to be a very interesting watch

2011-05-04T14:39:00.000-07:00

How much of the world is filtered out for you. http://www.ted.com/talks/eli_pariser_beware_online_filter_bubbles.html

Test Code that Doesn't

2011-04-22T13:28:00.000-07:00

Consider the following code taken from an automated testing suite:


   def group(self, group, options="", authUser=None, cmdOptions=""):
       if options != "":
           options = "-" + options
          
       output, rCode = self._run(cmdOptions, "list {} group {}".format(options, group), authUser, returnOutput=True)
       if rCode != 0 and output != None:
           lines = output.splitlines()
           if len(lines) > 1:
               for line in lines:
                   if line.find("[debug]") == -1:
                       group =  self._parseGroup(line)
           else:
               group = self._parseGroup(output)
             
       return group, rCode

What's especially interesting about this piece of code is that if the program being called succeeds and returns multiple lines, only the very last one is considered the actual output. If the program being called by _run fails, the return value is the text of what you asked for!

Though this is part of an automated testing suite, no real checks take place. The only thing it bothers to do is ignore debugging output. But that's handy!

Chat between frinds

2011-03-25T10:16:00.000-07:00

It's often the case where I learn more about programming from a conversation over google talk then I do form reading a book. This is a copy of one such conversation between two of my friends. I thought the content was good enough to actually post for others to read.

Sqrl says:
Feels nice to perfect a 468-line data model using LINQ extremely liberally

Llama says:
how does LINQ relate to a data model?

Sqrl says:
Probably the wrong word

There are a number of properties of my data model that I'm exposing that are little but fundamental interpretations of the data

That's where the LINQ resides

Llama says:
data operations then
technically speaking your data model should be POCO's

Sqrl says:
What's that?

Llama says:
Plain Old CLR Objects

Sqrl says:
Why?

Llama says:
ask yourself this question, what is a Data Model, simple answer, a unified representation of the data in a system
not a unified representatino of the logic in the system
by using POCO's you make your system firstly portable and simply definable

Sqrl says:
Well
I'm defining a system in which the rules can be changed dynamically by simply modifying some .csv or .xml files
For example, there is a number that defines how many slots you can put in your ship before the size in increased a level.
This size number is fundamental to the data itself, but emerges based on the rules
So, although it includes logic, I've included it in my data model
Defense and Speed are based on size and, again, fundamental
They also emerge from some logic

Llama says:
This is where i tell you, your system will never scale you've just written a very small idea
so if for example you want to do server side scaling of your game

Sqrl says:
Are you suggesting I should separate them into two different layers?

Llama says:
it won't happen and would be a nightmare
lol i'm suggesting you learn about software architecture
you can program, but the where and why needs to be taught

Sqrl says:
I try -_-

Llama says:
lol you suceed
dude
this is something i learned only 18 months ago at best

Sqrl says:
So would the problem be that so much computation is done server-side?

Llama says:
the problem is, if you try to do server side calculations you can simply push data easily in a POCO from client to server
your having to push the entire logic base with it and deploy the same logic on client and server
OR
do stateful server side objects which don't scale either

Sqrl says:
Well

Llama says:
meaning when you create an instance of an object it stays alive on the server, rather that data moving through a system

Sqrl says:
This particular data and rule set would be computed and immutable when the actual "game" part begins, I'll tell you that

Llama says:
having dicipline does NOT make up for architectural mistakes

Sqrl says:
hah
Fair enough
I'ma quote that, actually.

Llama says:
See your trying to apply a simple OOD which in truth is fundamentally flawed
by that, when you create an Object Oriented System, to be properly constructed it must implement this http://en.wikipedia.org/wiki/Solid_(object-oriented_design)
Its the only way of making an OO system scale and be properly designed

Sqrl says:
I never did understand where the line is drawn with SRP

Llama says:
more is better
meaning, if you have to break up logic into multiple logic blocks because it violates the single responsibility, then do so
so take this for example
you have a Repository object that handles CRUD (create, retrieve, update, delete) operations
now a repository pattern does not a happy llama make but its an easy way to explain this
Technically speaking the object can follow SRP if it does CRUD operations
but that can lead to a ton of operations right?

Sqrl says:
yeah

Llama says:
insert, update, delete, and data queries
so one could say that doing insert, update, delete, and select by id is one responsibility because its doing autonomous operations on an entity in the model
and any queries should be seperated out to a secondary or multiple objects in order to satisfy SRP
both are valid interpretations
however breaking it down further gives greater scope to the SRP making it more real

Sqrl says:
hrm
But certainly wouldn't create one object to generate the Defense, another to generate Speed

Llama says:
why not
they're components aren't they?
or is it making too many objects?

Sqrl says:

public int Speed
        {
            get
            {
                return (int)Math.Ceiling(this.AllSlots
                    .Where(i => i.SlotType == SlotType.Engine
                        || i.SlotType == SlotType.Universal)
                    .Where(i => i.SlottedSystem != null)
                    .Where(i => i.SlottedSystem is IShipEngine)
                    .Sum(i => (i.SlottedSystem as IShipEngine).Thrust)
                    / (float)this.Size);
            }
        }

That's it
Llama says:
ok, thats a horrible bastardization of a data layer
you did that in a getter? o.O

Sqrl says:
Hahahaha

Llama says:
dude, ICalculateSpeed ftw

Sqrl says:
Are you serious?

Llama says:
as a heart attack
you CAN use a factory to keep a singleton of it
but thats logic hiding in the data layer
its a calculation leading from one entity to a speed value
You do want to learn proper OO systems no?

Sqrl says:
Why would I use a singleton instead of a static method?

Llama says:
Its a piece of logic, which is encapsulated into an object
therfore keeping w/ the DIP principle you have an interface to define the operation, and an object instance to operate it
keeping a singleton just manages memory overhead
but you can manage that w/ the Factory
which yields flexibility
rather than a run of the mill rigidity that using a Utility class w/ a static method gives you
make sense?

Sqrl says:
Yeah
Damn good song btw http://listen.grooveshark.com/s/The+Truth+Of+A+Liar/2gag9R?src=5

Llama says:
i'll have to check it out on pandora

Sqrl says:
I can definitely see where the flexibility comes in
It builds more of an internal protocol-based system instead know-it-all master objects

Llama says:
see: God Object
suprisingly, it builds a stronger system with fantastic segregation
you can tune and tweak various parts of the system
AND
its bloody easy to unit test
you can create various proxy objects to plug into the system that mock actual logic, so your system can be 100% testable

Sqrl says:
And now

Llama says:
especially testing negatively

Sqrl says:
I have struggle with the decision of getting this thing done or plow through it so I can use it
It's a tool I wanted to use two weeks ago

Llama says:
Star Thugs?

Sqrl says:
yeah

Llama says:
hahaha
rebuild it yo
use it as a teaching moment for yourself

Sqrl says:
Well here's the good news
I'm still using MVVM, even though my models are a bit massive
So I can finish it off and refactor the models without remaining committed to my shit

Llama says:
sweet
well i got NUnit to start running my F# unit tests
namespace Llama.Test
open NUnit.Framework

[<TestFixture>]
type EndpointRegistryTests() =
    [<Test>]
    member x.add_value_to_registry() : unit =
        printfn "hello testing world 2"
        Assert.AreEqual(5, 5)

not bad for unit tests
Sqrl says:
Hahahaha

Llama says:
now i actually gotta fill in logic

Sqrl says:
Just testing the JIT
Iz coo

Llama says:
next is start testing components in my node server

Sqrl says:
How portable is the ViewModel architecture to ASP MVC?

Llama says:
depends on what you do
if its my framework Kronos
extremely
we actually had this type of layer for how data moves through layers

ViewModel -> Domain
View -> Controller -> Provider -> (Service : Optional) -> NHibernate
the domain object would live till the controller
then we'd do a transform using AutoMapper to a ViewModel to be used in the View
we use this for a very damn good reason, Domain objects are actually dynamically generated inherited objects that do lazy loading etc that are attached to a Session
So if we access a collection on an object in a view, we're literally running a db query in the view layer

Sqrl says:
lololol

Llama says:
So thats why we use ViewModels
So you know, Crystal thought my description of your getter as being a grose bastardization was rude
She says i should be nicer
>,>

Sqrl says:
Hahahaha

Llama says:
Granted, i won't be, because we devs are the way we are

Sqrl says:
'course

Llama says:
but its the thought that really counts
i told her it def wasn't the worst thing i've ever said

Sqrl says:
Gawd, what do you do when ignorant people call cute flash animations "programming"?

Llama says:
cuz they think it is

The way of Testivus

2011-03-02T07:37:00.000-08:00

A friend of mine linked me to TheWayOfTestivus.pdf the other day. It is a funny read that talks about unit testing and has a very pragmatic view on it. Read it enjoy it and apply it. I think you will find that it improves your development process if you do.

CodeProject has some gems in it.

2011-03-01T08:04:00.000-08:00

I friend linked me to this the other day and it changed how I program. It's not very often that one article changes the way I handle coding but this allowed me to clean up a lot of code. From the work in the article I have added one more function as well.

public static TResult Let(this TInput o, Func evaluator, TResult failValue)
            where TResult : class
            where TInput : class
        {
            if (o == null) return failValue;
 
            return evaluator(o);
 
        }

This one allows for the calling of functions that return a value.

Date Time you are doing it wrong again.

2011-02-16T13:59:00.000-08:00

The other day I reading the greatest developer fallacy or the wisest words you'll ever hear and then today I found some code that I think illustrated his point that learning it when you need it isn't always the way to go. This code looks very much that way. Although I think a quick Google search would have found better code then this even if you didn't know what words to look for.

System.Text.StringBuilder mxIsDt = new System.Text.StringBuilder();
mxIsDt.Append(DateTime.Now.Year.ToString());
mxIsDt.Append(DateTime.Now.Month.ToString());
mxIsDt.Append(DateTime.Now.Day.ToString());
mxIsDt.Append(DateTime.Now.Hour.ToString());
mxIsDt.Append(DateTime.Now.Minute.ToString());
mxIsDt.Append(DateTime.Now.Second.ToString());
string mxDate = mxIsDt.ToString();

Which converts into around 70 lines of IL and takes just 19160 milliseconds to complete.   Now my question is why wouldn't you use ToString on DateTime to do this.

var d = DateTime.Now.ToString("yyyyMdhms");            
Which takes 8 lines or less in IL and takes 1213 milliseconds to complete. It's way less code easier to maintain and examples on how to do this can be found all over the web.

Date Time You did it wrong.

2011-01-03T10:49:00.000-08:00

This is a priceless gem I found today

TranslateText("MonthName"+(DateTime.Now.Month-2).ToString("D2"),"")

It will even work for 10 months out of the year.

It should be

TranslateText("MonthName"+(DateTime.Now.AddMonths(-2).Month).ToString("D2")
Which works for 12 months out of the year.

Getting the value of a property through reflection.

2010-07-27T07:31:00.001-07:00

For a project I am working on I needed to retrieve the value of a property. Problem was I had a string that told me the name of the property. Most .NET people out there would say just use reflection stupid. Which is what I did but it was a learning experience for me. This is my first foray into reflection. Here is the code.

public static object GetPropertyValue(object ObjectInstance, string WantedProperty)
        {
            var aviableProperties = ObjectInstance.GetType().GetProperties();
            var workingProperty = aviableProperties.FirstOrDefault(c => c.Name == WantedProperty);
            if (workingProperty != null)
            {
                return workingProperty.GetValue(ObjectInstance, null);
            }
            throw new ApplicationException(string.Format("The Property {0} was not found in the class.", WantedProperty));
        }

ValidationAttribute verses the contextual validation

2010-07-13T15:56:00.001-07:00

This last week I got tasked with building some validation for the customer object in our new system here at work. Since we are using MVC2 I can use DataAnnotations to do this. Which in most situations would just mean I throw on some attributes like [Required(ErrorMessage="No soup for you")] But not where I work we can’t have one set of required fields no. Each country has a different set of required fields. This means that I not only need to know what the data I am validating is but what context it is validate in.

This means I can’t use

public bool IsValid(object value)

since it has no idea of context. However there is a second overload of IsValid that will work. It took me a bit to understand how this works but it is very nice.

protected ValidationResult IsValid(object value, ValidationContext validationContext)

the ValidationContext gives you access to the object that’s data member you are validating. By using the ObjectType and ObjectInstances of the property you can get access to all the data members of the current object.

Using the above functions It is easy to create a validator that checks to see if a country should or shouldn’t be validate for a given data member and then validate it if I need to.

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field)]
public class RequiredForCountry : ValidationAttribute
{
   public string CountryIds { get; set; }
   public int TermId { get; set; }

   protected override ValidationResult IsValid(object value, ValidationContext validationContext)
   {
       if (string.IsNullOrEmpty(this.CountryIds))
       {
           throw new System.ApplicationException(string.Format(
                              "The property {0} is not set up correctly in class {1}",
                             validationContext.MemberName,
                             validationContext.ObjectType.FullName));
       }
       var countryId = GetCountryID(validationContext);
       if (CountryIds.Contains(countryId.ToString()))
       {
           if (value == null)
               return new ValidationResult(TermId.ToString());
           var strCheck = value as string;
           if (strCheck != null && strCheck == string.Empty)
               return new ValidationResult(TermId.ToString());
       }
       return ValidationResult.Success;
   }      

   private int GetCountryID(ValidationContext context)
   {
       switch (context.ObjectType.Name)
       {
           case "Customer":
               return (context.ObjectInstance as ICustomer).MainAddress.Country.Id;                  
           case "Order":
               return (context.ObjectInstance as IOrder).Country.Id;                  
           default:
               return -1; // eventually this will throw an error
       }
   }      
}

While the above code isn’t the prettiest code I have ever written it gets the job done and allows me to not have to write custom validation for every country.

Proper Use of Properties

2010-06-30T10:49:00.001-07:00

Today we are talking about properties. How to use them and more importantly how not to use them.

When dealing with properties like they wore written before 3.5 you should have some thing that looks like this.

private string _test;
public string Test
{
    get { return this._test; }
    set { this._test = value; }
}

I love properties like this it’s only slightly less cool then using the 3.5 version of a property. The thing I don’t like about a property like this is when a programmer decides he doesn’t need to user the property and accesses the _test variable directly inside of the class to make a change. So like this

this._test = "some string";

I consider this bad programming. It makes maintaining code much more difficult and adds an unnecessary level of complexity. You have to look at two things now to see how a value gets set or modified. To do all the access through the property takes about the same amount of work and ends up in a much cleaner code file.

this.Test = "Some string";

Is actually one less key stroke and is so much easier to work with.

This code just rocks.

2010-06-29T12:21:00.001-07:00

Usually I post examples of code that sucks. Today I am posting an example of code that just rocks. Why does it rock because it solves a problem in a very elegant way. I have had to write code to do the same thing several times but mine never looks or works as this example. The code comes from ravenDB’s server. It handles the case where you need to run in elevated privileges but the program wasn’t started at such a state.

private static void AdminRequired(Action actionThatMayRequiresAdminPrivileges, string cmdLine)
{
    var principal = new WindowsPrincipal(WindowsIdentity.GetCurrent());
    if (principal.IsInRole(WindowsBuiltInRole.Administrator) == false)
    {
        if (RunAgainAsAdmin(cmdLine))
            return;
    }
    actionThatMayRequiresAdminPrivileges();
}

private static bool RunAgainAsAdmin(string cmdLine)
{
    try
    {
        var process = Process.Start(new ProcessStartInfo
        {
            Arguments = cmdLine,
            FileName = Assembly.GetExecutingAssembly().Location,
            Verb = "runas",
        });
        if (process != null)
            process.WaitForExit();
        return true;
    }
    catch (Exception)
    {
        return false;
    }
}

Wow this one takes the cake.

2010-01-20T11:34:00.000-08:00

So of late I have been working on a older system created in .NET by a delphi programmer. It has some very interesting behaviors.

private string Xml { set { this.Address = value; } }

public FooClass(PaymentInfo info)
: base(info)
{
this.Xml = string.Format("Some random string goes here" . .

The problems with this are many. The least of which would be the fact they created a property Xml that just sets another property Address. Why would you do this. You can just call Address.

Walk Of Shame.

2009-08-27T12:13:00.000-07:00

So today as I am looking into why a program failed. I ran across a wonderful little bug that was completely my fault. The offending line of code is.

   76 this._AviableCabinets.RemoveAt(this._AviableCabinets.FindIndex(c => c.Name == LanguageDB.GetText("SelectDestLocalAllCabinetsText")));

The error it will throw is index out of bounds.

The solution is easy.

   76 var cLoc = this._AviableCabinets.FindIndex(c => c.Name == LanguageDB.GetText("SelectDestLocalAllCabinetsText"));

   77             if (cLoc > -1)

   78             {

   79                 this._AviableCabinets.RemoveAt(cLoc);

   80             }

Some Times it is better to not do it all on one line.

Getting the day of the week the first day of the month is.

2009-07-24T08:05:00.000-07:00

A co-worker of mine is learning to program and decided to write a calendar program. He needed a way to find out what day of the week the first day of the month would be. In his explaining of how he was doing it we came up with the following code that would work for his needs.

   17 static void Main(string[] args)

   18 {

   20     string date = "1-1-09";

   21     string dofw = GetDayOfWeekFromString(date);

   23 }

   25 private static string GetDayOfWeekFromString(string date)

   26 {

   27     DateTime desiredDay = new DateTime();

   28     DateTime.TryParse(date, out desiredDay);

   29     return desiredDay.DayOfWeek.ToString();

   30 }

After I gave him that code I decided to just pack it into an extension function. Like so.

   36 public static string GetFirstDayOfMonthDayOfWeek(this DateTime dt)

   37 {

   38     DateTime firstOfMonth = new DateTime();

   39     if (DateTime.TryParse(string.Format("{0}/1/{1}", dt.Month, dt.Year), out firstOfMonth))

   40     {

   41         return firstOfMonth.DayOfWeek.ToString();

   42     }

   43     return string.Empty;

   44 }

Which can be called like this.

   21 string dofw = DateTime.Now.GetFirstDayOfMonthDayOfWeek();

Hope someone else finds it of use.

My python hours worked calc.

2009-07-23T15:57:00.000-07:00

I use this horrid little piece of code to tell me how long i work each day. It isn't all that grate but it gets the job done.


ClockInHoure = 7
ClockInMinuet = 10
ClockOutHoure = 5
ClockOutMinuet = 0
lunchstartHoure = 11
lunchstartMinuet = 28
lunchEndHour = 12
lunchEndMInuets = 05

#caculate hours worked
mHours = 12 - ClockInHoure
aHours = ClockOutHoure
#get theminuets 
mMinuets = mHours * 60 - ClockInMinuet
aMinuets = aHours * 60 + ClockOutMinuet

tMins = mMinuets + aMinuets

Lhours = lunchEndHour - lunchstartHoure
lmins = lunchstartMinuet - lunchEndMInuets

bMin = Lhours * 60 - lmins


tMins -= bMin

tHour = tMins / 60
tMinuets = tMins % 60
if(tMinuets < 10):
    pMin = "0"+ str(tMinuets)
else:
    pMin = str(tMinuets)
print "%d:%s" %(tHour,pMin )

Setting the selected treeItem in a treeview on right click

2009-07-20T11:40:00.000-07:00

So over the past several weeks I have been working with a lot of TreeViews in WPF I use a HierarchicalDataTemplate with a custom ItemContainerStyle for my nodes in the tree. I have been having a rather hard time finding a way to easily set the right clicked on node before the context menu is opened on it. My HierarchicalDataTemplate consists of a stackpanel with a context menu and a image and textblock.

In the ContextMenu_Opened function i put the following code.

   93 var cMenu = sender as ContextMenu;

   94             var tbase = (cMenu.PlacementTarget as StackPanel).DataContext as BasicTreeViewBase;

   95             tbase.IsSelected = true;

Which will set my selected item to true. The BasicTreeViewBase is a ViewModdle object baised off of the code found at TreeViewWithViewModel and is rather simple.

Some times you just have to rename files.

2009-05-06T06:56:00.000-07:00

So I needed to rename a bunch of files. I needed to add the size of the file as a postfix. Same name just an adition of 16x16 which when doing it by hand is tedious. So this little script was created. You have to dump it into the same folder as the files you are working with, and you have to put the path in walkPath. I could have it pull the current directory from the os but that would take work.

import os

walkPath = r"some disk path"

for d in os.walk(walkPath):

dirpath, dirnames, filenames = d

for a in filenames:

if a.endswith(".py"):

pass

else:

print a

aSplit = a.split(".")

os.rename(a,aSplit[0]+"16x16."+aSplit[1])

Strings in c++

2009-03-16T07:25:00.000-07:00

I made the mistake of taking a c++ class. Well itn's not a mistake it is good to be reminded of how much effort things are in c++. Take strings for example. In c# if you want to lower case a string you do a str.ToLower() and it is lower case in c++ you have to do some thign like this.

   30     static void ToLower(string &itext)

   31     {

   32         transform(itext.begin(), itext.end(), itext.begin(), (int(*)(int)) tolower);

   33     }

This one wasn't all that bad it is still just one line. This what the first one I needed

for the project I am working on at the moment.  The other one I wished I had on several

was str.Trim() just to clear off the white space. So I spend 5 minuets googling and found

something simlar to this.

    35 static void Trim(string &itext)
   36 {
   37     int startLoc = itext.find_first_not_of(" \t\n");
   38     int endLoc = itext.find_last_not_of(" \t\n");
   39     if((std::string::npos == startLoc) || (std::string::npos == endLoc))
   40     {
   41         itext = "";
   42     }
   43     else
   44     {
   45         itext = itext.substr(startLoc,endLoc - startLoc + 1);
   46     }
   47 }

it dosn't do any thing but white space but still it is better then a kick in the face.

C# is so much easier then C++

2008-12-31T11:24:00.001-08:00

I have been given the opportunity to work on an old c++ program for work this last couple works. I just have to say that C# is so much easier to follow and understand then MFC any day of the week. I did learn how to check if a directory exists before creating it though.

 1569 if(GetFileAttributes(_T(tPath)) == INVALID_FILE_ATTRIBUTES)

 1570     {

 1571         SECURITY_ATTRIBUTES sa;

 1572         sa.nLength = sizeof(SECURITY_ATTRIBUTES);

 1573         sa.lpSecurityDescriptor = NULL;

 1574         sa.bInheritHandle = FALSE;

 1575         CreateDirectory(_T(tPath),&sa);

 1576     }

Just thought I put this here for when I need it again.

Delimiters

2008-12-10T07:44:00.001-08:00

Let’s talk about string delimiters and why you shouldn’t hard code them. Take the following example.

   16 return String.Format("#Command#{0}#{1}#{2}#{3}#{4}#{5}#{6}#{7}#{8}#{9}", completePath,

   17                                                                       GUID,

   18                                                                       UID,

   19                                                                       otherinfo,

   20                                                                       option1,

   21                                                                       displayText,

   22                                                                       filter,

   23                                                                       someint.ToString(),

   24                                                                       file,

   25                                                                       seckret);

It and three other ones just like it can be found in the code I am currently working on. Now when you see this you think that isn’t all that bad. Until you need to change the delimiter for one reason or another. You could go with something like the following but it not the most readable thing you will ever see.

   28 return String.Format("{10}Command{10}{0}{10}{1}{10}{2}{10}{3}{10}{4}{10}{5}{10}{6}{10}{7}{10}{8}{10}{9}",

   29                                                                       completePath,

   30                                                                       GUID,

   31                                                                       UID,

   32                                                                       otherinfo,

   33                                                                       option1,

   34                                                                       displayText,

   35                                                                       filter,

   36                                                                       someint.ToString(),

   37                                                                       file,

   38                                                                       seckret,

   39                                                                       commandStringDelimiter);

This is a little better now you can just change “commandStringDelimiter” to a different value when you need to change the delimiter. But it’s not verry readabel a better soluction is to do build a function that can build the string for you. This allows you to hide how it is created and keep it all in one place. Like this.

   54 public string BuildFileCommandString(params string[] options)

   55         {

   56             List<string> cStr = new List<string>();

   57             cStr.Add("Command");

   58             cStr.AddRange(options);

   59             return this.commandStringDelimiter + string.Join(this.commandStringDelimiter, cStr.ToArray());

   60         }

You would call it like this.

   41 BuildFileCommandString(completePath,

   42                        GUID,

   43                        UID,

   44                        otherinfo,

   45                        option1,

   46                        displayText,

   47                        filter,

   48                        someint.ToString(),

   49                        file,

   50                        Seckret);

You will also notice that I used a string.Join rather then a string.Format this just makes it more readable to me.

Cool if statement.

2008-10-29T12:14:00.001-07:00

I ran into this little if statement while fixing moving some code around today. It does something like 18 string functions and that is assuming that Path.GetExtension is just one string function call.

   30 if (Path.GetExtension(path).ToLower() == ".tif"

   31     || Path.GetExtension(path).ToLower() == ".pdf"

   32     || Path.GetExtension(path).ToLower() == ".jpg"

   33     || Path.GetExtension(path).ToLower() == ".png"

   34     || Path.GetExtension(path).ToLower() == ".gif"

   35     || Path.GetExtension(path).ToLower() == ".jpeg")

I decided that it needed to be removed and I replaced it with this.

   25 string ext = Path.GetExtension(path).ToLower();

   26 List<string> validExt = new List<string> { ".tif", ".pdf", ".jpg", ".png", ".gif", ".jpeg" };

   27 if(validExt.Contains(ext))

But you could also do this with LINQ

   25 var extensions = new List<string> { ".jpg", ".jpeg", ".tif", ".png", ".gif" };

   26 if ((from i in extensions where i == Path.GetExtension(dir).ToLower() select i).Count() > 0)

I like the second version the best but that is just personal preference. Both alternatives are way better then the first option.

Fun with directory security

2008-10-28T16:07:00.001-07:00

So for the last couple weeks we have been having a problem with our installer and it’s setting of access rights on directories. This was mostly a problem with vista and well I got made the “vista access rights expert” so that translates into you get to figure out what is wrong.

   15 static void Main(string[] args)

   16 {

   17     string aPath = @"C:\ProgramData\TestApp";

   18     string fPath = Path.Combine(aPath, "files");

   19     Directory.CreateDirectory(fPath);

   20     SetPermissions(aPath);

   21 }

   22 public static void SetPermissions(string dir)

   23 {

   24     DirectoryInfo info = new DirectoryInfo(dir);

   25     DirectorySecurity ds = info.GetAccessControl();

   26     ds.AddAccessRule(new FileSystemAccessRule(@"BUILTIN\Users",

   27                      FileSystemRights.FullControl,

   28                      InheritanceFlags.ContainerInherit,

   29                      PropagationFlags.None,

   30                      AccessControlType.Allow));

   31     info.SetAccessControl(ds);

   32 }

The code started out looking something like this. It adds a security rule for all users to the folder allowing use users access to data on the local system. Problem is that if a program tries to access the files it throws an access denied error. Even though the user’s effective permission to the folder is FullControl. He doesn’t have any access to the files in the folder, and can’t access the files dir at all. After several hours of reading and trying different things all the smart people I drug into help me with the problem came up with three small changes that make it all work without a problem.

   15 static void Main(string[] args)

   16 {

   17     string aPath = @"C:\ProgramData\TestApp";

   18     string fPath = Path.Combine(aPath, "files");

   19     Directory.CreateDirectory(aPath);

   20     SetPermissions(aPath);

   21     Directory.CreateDirectory(fPath);

   22 }

   23 public static void SetPermissions(string dir)

   24 {

   25     DirectoryInfo info = new DirectoryInfo(dir);

   26     DirectorySecurity ds = info.GetAccessControl();

   27     ds.AddAccessRule(new FileSystemAccessRule(@"BUILTIN\Users",

   28                      FileSystemRights.FullControl,

   29                      InheritanceFlags.ObjectInherit |

   30                      InheritanceFlags.ContainerInherit,

   31                      PropagationFlags.None,

   32                      AccessControlType.Allow));

   33     info.SetAccessControl(ds);

   34 }

The changes that needed to be made wore creating the base directory and setting permissions before the sub folder was added. In the set permissions folder there was also a second flag added to the inheritance option of FileSystemAccessRule that changed it so that both files and folders inherited the settings.

The DAO Class

2008-10-06T07:36:00.001-07:00

In the project I am currently working on we have lots of objects and each object has it's own DAO class. This is fine every class should have a DAO object. Or I should say that there should be a DAO object that every class can use to access it's data from it's storage location. The thing is that most systems I have worked with don't do it this way. They have a DAO object that creates objects. Not objects that use the DAO system to create them selves.

I will give you an example. Say you have a class called foo and you want to get an instance of it from the database. With the DAO as create system you have to do the following.

   20 foo bar = fooDAO.GetFooByID(fooID);

bar gets created in the fooDAO object so basically any place where you want to work with foo you have to have fooDAO around and visible in scope as well. No in the way I like to see things like this done a foo object has a reference to the fooDAO in his class so when you are creating the foo object you just say:

   19 foo bar = new foo(fooID);

So some people will say you haven't accomplished all that much by pushing it down into the class. Which is true you still have the same amount of code, but when the guy that writes the business logic is working with foo now he doesn't have to know about fooDAO or care about it. He gets to make calls like.

   22 bar.Save();

rather then calls like this.

   23 fooDAO.UpdateFoo(bar);

Then when the day comes where it is time to stop using the cheep read free database you decided to use and switch over to a more powerful database. All of your updates can be done one place for each class type, and if you designed it right and use an well defined interface for your DAO object you will be able just to change the DAO object reference in each class.

Best varible name ever.

2008-10-01T08:17:00.001-07:00

So today I was looking at a coworker’s code. I am doing CURD processes for the system I am working on this isn’t creative code or even variable code beyond you change the names of what you are keeping in the database. But while grabbing his code to use as a template for the new function I ran across this little pearl of code. My work went from boring to enjoyable in second all because of one line of code that made me laugh. Her it is.

  716 object of_my_affection = command.ExecuteScalar();

Sometimes having a bit of fun in your code makes it better than all the naming conventions you could ever use.

Returning the comparison results

2008-09-26T06:52:00.000-07:00

Over the last couple weeks I have been looking at some of my old code as well as going over other peoples projects. A personal pet peeve of mine keeps popping up in the code the worst part is when I started out programming I did the same thing. It’s when you do a Boolean comparison then return true or false rather than just returning the results of the comparison. Below is an example of what I am talking about.

   21 if (foo == otherFoo)

   22 {

   23     return true;

   24 }

   25 else

   26 {

   27     return false;

   28 }

The above is an example of what not to do. There have been many times in my life where I have done this not thinking about what I was doing. I am glad to say that time has passed. I have talked to others about it and they say they do it because it is more explicit and easier to read. I have a hard time agreeing with this stance how can the above be easier to read then the following.

   21 return foo == otherFoo;

It’s short simple and easy to read.

Adding unique items to a list the fun way

2008-09-19T08:13:00.000-07:00

In some of the work I do I have to combine several lists into one list and only add a item if it is unique by some arbitrary rule. I have done this so often in the last month I was about to write a code snipit for it. Then I started learning about template functions and realized I could just make one function to do this for me. I started out using Contains(vale,IEqualityComparer<>) to see if the item was already in a list this was a lot of effort and I never did figure out how to make a IEqualityCompare delegate. But there is this nice little method on lists called Exists which takes a predicate for comparisone. Which solved all my problems. The extention function I came up with seen below is probaly my favrite so far.

36 public static void AddIfUnique<T>(this List<T> tList, T toInsert, Func<T,T,bool> func)
37 {
38    if (!tList.Exists(p => func(p,toInsert)))
39    {
40        tList.Add(toInsert);
41    }
42 }

The usage for it is as follows.

15 DirectoryInfo mainDir = new DirectoryInfo(@"c:\");
16 List<FileSystemInfo> item = new List<FileSystemInfo>();
17 item.AddRange(mainDir.GetFiles());
18 DirectoryInfo mainDir2 = new DirectoryInfo(@"e:\");
19 List<FileSystemInfo> tList = new List<FileSystemInfo>();
20 tList.AddRange(mainDir2.GetFiles());
21 tList.ForEach(c => item.AddIfUnique(c, (k, j) => k.Name == j.Name));

In the above code the item list will end up with all file names that are unique. While this example is not the most useful example out there it does show how it works.

ForEach the functional way.

2008-09-16T06:16:00.000-07:00

Before I started my current job I worked as a software tester and did a lot of automated testing in python. I love working in python it takes most of the effort out of programming you just write down what you want and it compiles and runs. Down side is python is not a strongly typed language and I picked up some very bad habits form python. Which others have proceeded to beat out of me. One thing that python did have that I truly miss is the map function. It makes working on lists so much cleaner, and when you mix that with lambda you come out being able to do a lot of work in very few lines of code. A couple weeks ago I was talking with a friend of mine about how C# had no map functions and how if I had it I could shrink a bunch of code down to next to nothing. The following functions are the results of that conversation. At the time I didn't want to return a list at the time I was doing a lot of file maintenance and just wanted to traverse the folder structures in a clean way. So llama being the guy he is emailed me these two functions.

12 public static void ForEach<T>(this IEnumerable<T> list, Action<T> func)
13 {
14     foreach (T t in list)
15     {
16         func(t);
17     }
18 }
19 
20 public static void ForEach<T>(this IEnumerable<T> list, Action<T> func1, Action<T, Action<T>> func2)
21 {
22     foreach (T t in list)
23     {
24         func2(t, func1);
25     }
26 }

Here is an example of how they can be used.

14 public static void WalkFiles(string filePath, Action<string> workerFunc)
15 {
16     if (WalkFilesCont)
17     {
18         if (Directory.Exists(filePath))
19         {
20             System.IO.Directory.GetFiles(filePath).ForEach(workerFunc);
21             System.IO.Directory.GetDirectories(filePath).ForEach(workerFunc, WalkFiles);
22         }
23     }
24 }

I use them in a lot of other areas I even have one variation that behaves like a map in python I don't do much work on lists though where I need to see a result passed back so it doesn't get as much use. These first function gets used quite a bit more than I expected.

Programming the hard way

2008-09-11T11:07:00.000-07:00

On several occasions in my short life I have ran across coders that insist on not using the prebuilt classes and functions that come with .net. I can understand not using a 3rd party lib when you write the entire product for the ground up, but if you are using .net you might as well use it to its fullest extent.
Take the following code:

 9    using (FileStream fs = new FileStream(FilePath, FileMode.Open))
10    {
11        using (BinaryReader br = new BinaryReader(fs))
12            rawTiffData = br.ReadBytes((int)fs.Length);
13    }
14    tiffData = Convert.ToBase64String(rawTiffData);
15 
16    string name = tiffPath.Substring(tiffPath.LastIndexOf('\\') + 1,
17        tiffPath.LastIndexOf('.') - tiffPath.LastIndexOf('\\') - 1);

It will open up a tiff file and read in all of the bytes and then convert it to base 64 encoding. Then he gets the name of the file without its extension. Let's do the same thing but using the .Net functions that should be used.

 9    rawTiffData = File.ReadAllBytes(this.FilePath);
10    tiffData = Convert.ToBase64String(rawTiffData);
11    string name = Path.GetFileNameWithoutExtension(this.FilePath);

The second section of code is almost self documenting. You can at a glance see what is going where and why. You also don't have to worry about getting your substring wrong or someone a year down the road coming in and making a small change to the substring call to make it better. Adding a bug that is not trivial to find.

Good code layout.

2008-09-10T07:51:00.000-07:00

Recently I have been looking at and writing a lot of c# code. It's nice when you get paid to program in the language you want to learn. I have noticed in several places where people build the same complete object with one or two difference in two separate locations in the code usually a if else statement. I have a big belief in don't repeat yourself when programming. If you find you are writing the exact same code or close to it over and over again you are doing something wrong. Here is a good example of what I am talking about. It also isn't too far from the code that made me want to write this post.

String Foo1 = "3.4.5";
String Foo2= "3.4.6";
mObject boo = null;
if(new Version(Foo1) > new Version(Foo2))
{
    boo = new mObject
    {
        vLam = "yummy",
        jArp= "jello",
        cFile= "No"
    };
}
Else
{
    boo = new mObject
    {
        vLam = "yummy",
        jArp= "jam",
        cFile= "Yes"
    };
}

In the above code we see an example of what not to do. You are creating dynamic objects to make a decision that could be made using a string comparison operator which isn't really on topic but is worth mentioning. Also you have double the code you need in creating your object.

Now let's do it in the cleaner way that I would like to see one instantiation and then just assign the values as we go.

String Foo1 = "3.4.5";
String Foo2= "3.4.6";
bool isFoo2Less = Foo1.CompareTo(Foo2) > 0
mObject boo = new mObject
{
    vLam = "yummy",
    jArp= (isFoo2Less)? "jello" : "jam",
    cFile=(isFoo2Less)? "No" : "Yes"
};

We end up with less lines of code and even though we add a variable to the mix and do two checks. The maintainability of this code is much easier and will cause less confusion over the life of the program.