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PIEBALD rolls a three and reaches for his GOF book...
The closest I see is Proxy, but that's more about deferred instantiation.
As mentioned by others, it's also close to Singleton, yet possibly Singleton done right. (The standard Singleton Pattern is filth.)
Maybe this could be called the Library Pattern.
Anyway, I do that a lot too. Most recently as a store for RegEx instances which I use frequently.
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Flyweight?
Starting to think people post kid pics in their profiles because that was the last time they were cute - Jeremy Falcon.
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OriginalGriff wrote: But ... is that a pattern?
Yes, it is. I would refer to it as the static OGDictionarySingleton.
OriginalGriff wrote: I hope not, I might have to stop using it
Why?
The definition of a pattern is a piece of reusable code that solves a given problem. Does your manager not allow for tested and documented solutions?
Bastard Programmer from Hell 
If you can't read my code, try converting it here[^]
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Because most patterns are a waste of time, but worshipped as the One True Holy Grail of Computing by those that learn it. And then force all applications they write to fit that pattern regardless of the appropriateness.
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
AntiTwitter: @DalekDave is now a follower!
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OriginalGriff wrote: Because most patterns are a waste of time, but worshipped as the One True Holy Grail of Computing by those that learn it. And then force all applications they write to fit that pattern regardless of the appropriateness.
..you are interacting with the wrong kind of people. Regardless of your silver bullet, I will not follow in the procession.
"Most patterns"? Which are you referring to? They're used throughout the .NET Framework, from factories and adapters to decorators. Just my favourite, the memento, isn't included (afaik, which doesn't mean much).
A pattern is simply a formalized piece of code that solves a problem. You have a list of those in your intellisense, don't you? Those snippets are formalized pieces of code that follow a specific pattern and that have a name.
Now how does one take one of those templated pieces of code and make a holy grail of it? Is it some consultant, yammering to implement an event-receiver in C#?
Code needs to be kissable clean; no patterns "just" to show of that you know something, the simplest solution is always the preferred one. But please, do follow the pattern of wrapping your connections and commands in a using-clause, do use parameterized queries, and please, use the factory-method that is included in the connection object to create your command. It saves a lot of time when rewriting to another provider.
..maybe I should just put my rambling in an article, as a lot of devs that I respect are not too fond of patterns for some weird reason. Tell me, do you vary your code to show a form, or does that happen to be another unnamed pattern that you repeat? 
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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Eddy Vluggen wrote: But please, do follow the pattern of wrapping your connections and commands in a using-clause, do use parameterized queries, and please, use the factory-method that is included in the connection object to create your command. It saves a lot of time when rewriting to another provider.
Can't tell if you're being sarcastic because there's not much there I agree with (except maybe the parametrised queries, even then ...) Using older dated systems/databases/external devices some of that is not even possible let alone sensible. But this is not really the correct forum for that and I'm off to bed anyway.
Installing Signature...
Do not switch off your computer.
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Eddy Vluggen wrote: maybe I should just put my rambling in an article,
Why not? Do it... I really think it might bring a nice debate in the board
M.D.V. 
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
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Eddy Vluggen wrote: maybe I should just put my rambling in an article, as a lot of devs that I respect are not too fond of patterns
I am sure I would learn something valuable, if you did !
«While I complain of being able to see only a shadow of the past, I may be insensitive to reality as it is now, since I'm not at a stage of development where I'm capable of seeing it.» Claude Levi-Strauss (Tristes Tropiques, 1955)
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Yes, 10 novel ways to obfuscate your code and get a higher LOC
Working on it, and trying to make it usefull, instead of another summary on which pattern does what and whether it is creational or recriational.
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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I don't care for patterns in my code and I definitely don't care for vague terms like "clean" code.
I only care for code that's short, safe to fail, easy to test, and understandable by a college freshman in less than 2 weeks.
Nevertheless, please write about the patterns you think are worthwhile; preferably with a not-too-generic example. You might teach us something worthwhile.
Also, if anyone knows of a must-read regarding the use of factory-pattern, please share. I really hate it and I'm looking for material to nuance my feelings towards it.
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killbot5000 wrote: understandable by a college freshman in less than 2 weeks.
If you can't explain your pattern in 5 minutes time, then you probably don't understand it. That is assuming that your freshman knows how to code 
killbot5000 wrote: Also, if anyone knows of a must-read regarding the use of factory-pattern, please share.
That's the pattern I'm opening the article with. May take another day or two.
killbot5000 wrote: I really hate it
Yah, then you had the wrong explanation. Most important question to answer is always "what's in it for me?", and a factory has an easy to explain benefit 
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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If you can't explain your pattern in 5 minutes time, then you probably don't understand it. True enough. I was only trying to explain our somewhat informal guideline at work; a junior should be able to master any one of our projects in a maximum of 2 weeks time, without any help from a senior. In general, we don't trust juniors to correctly identify or implement various patterns, so we don't approach our code as such.
But, of course, we do want juniors to be able to work for clients almost instantly. *grin*
It's mostly an effort of gathering/vetting the right tools; ones that are easy to use, easy to test, and with a low code footprint. Around 90% of our R&D is spend on simplifying the way we do things.
But, to come back to factory pattern:
I hate it because it often seems the right choice, but, for me, it has never panned out. Every time I try it out, I end up over-designing my data models and adding an abstraction layer I don't really need. In the end, I usually remove it and end up with (almost embarrassingly..) simple classes with distinct data.
It can be infuriating.
I try to come up with a clever looking data structure, hope factory pattern fits the bill, and *boom* suddenly I see there's no need for abstraction whatsoever, vastly reducing my test code and simplifying my DB design. 
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killbot5000 wrote: Every time I try it out, I end up over-designing my data models and adding an abstraction layer I don't really need.
Might be easier to not try it until you need one. To find a scenario where the use of it would be beneficial, you'd need some decent example. The abstract examples didn't help me much.
killbot5000 wrote: *boom* suddenly I see there's no need for abstraction whatsoever, vastly reducing my test code and simplifying my DB design.
KISS is always the best choice. Someone else will inderstand it better when reading, updates are easier and less complicated, and less code in general means fewer bugs.
I'll give you a ping when I'm done and posted it
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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As promised[^], with a not-too-generic example
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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I was really wondering why you did not want to use a pattern so badly you would strike it from your code.
I bought the GoF book, and was excited to be able to communicate better designs quicker. But, like you, I found zealots who used patterns like an indentation style. The could not code without them, and would convolute a simple program with them.
I moved away from them, but use patterns (factory, most often) where they are clearly a solid approach, but NEVER worrying about doing it exactly as prescribed.
But your comment felt like "I refuse to indent my code because there are indentation extremists"...
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The only pattern worth using is GIWAGO - 'Get It Working And Get Out!' 
veni bibi saltavi
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It is the Tinder pattern.
(A collection of singletons)
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Swipe left! Swipe left!
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
AntiTwitter: @DalekDave is now a follower!
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Boom! You sir, have won the Internet today.
Jeremy Falcon
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Duncan Edwards Jones wrote: the Tinder pattern
That's a very tricky one since you have to implement your own MultiTassking, and MultiBedding.
«While I complain of being able to see only a shadow of the past, I may be insensitive to reality as it is now, since I'm not at a stage of development where I'm capable of seeing it.» Claude Levi-Strauss (Tristes Tropiques, 1955)
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Yes, it's called the "static cling" pattern as nothing put into the dictionary ever gets garbage collected.
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Global variables of any flavor have that problem, that's why I would only do something like that for things that remain mostly constant throughout the program's lifetime.
Remember the Win32 hInstance parameter? It was passed to WinMain() as a parameter and remained unchanged from then on and you needed it for many Win32 API calls. The four bytes for a global variable were not much of a problem (yes, it was memory that was not cleaned up until the program ended) and it sure beats passing around that value to every window and dialog.
When memory hogging is under control, state is not problematic (or even constant), and when I need it all over the place, I will not go through the trouble of routing that object or variable to the remotest parts of the application.
I have lived with several Zen masters - all of them were cats.
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Marc Clifton wrote: nothing put into the dictionary ever gets garbage collected.
Is there no way to handle that >?
«While I complain of being able to see only a shadow of the past, I may be insensitive to reality as it is now, since I'm not at a stage of development where I'm capable of seeing it.» Claude Levi-Strauss (Tristes Tropiques, 1955)
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OriginalGriff wrote: So I have a private constructor, a static Dictionary containing all created instances, and a static method which fetches the instance:
I only see a downside
you create an "instance" and fill it with data // no problems
...
later fetch your "instanse" and do the work // ...wow, that went pretty quick
all you've done is taken away the ability of the code editor/compiler to check the item exists and built in another opportunity for a hard to find run-time problem. (if you missed it check the spelling, because the compiler wont do that for you.)
and the upside isn't there, a separately declared list left empty takes few resoures.
Installing Signature...
Do not switch off your computer.
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OriginalGriff wrote: I hope not, I might have to stop using it ... 
Bullshit!
Design patterns were never intended to be the last word and the answer for everything. There is no law against coming up with your very own way of doing something, no matter what some gurus want to have you believe.
The SOLID faction would condemn you for breaching the single responsibility principle and using something akin to global variables and singletons. So what?
My personal sin is a message broker that I use in almost any UI. When compared to awkward wasteful automatic routing in a large UI tree or fragile code bloating manual routing, having a message broker as a singleton is a blessing. Some object registers with the broker to be notified when a specific message is sent, another object sends the message at some time and the broker looks up all subscribers and calls their event handlers. This is reasonably fast (no searching the entire UI tree) and absolutely unproblematic. The only weak spot is that an object better unregister its subscriptions when it is being destroyed, otherwise the broker may get bogged down servicing dead subscriptions.
Yes, global variables or singletons may be problematic, but sometimes you can have all of the benefits without any complications. I would immediately redesign if any complications materialized, but not simply for the purity of some design philosophy's sake. Why throw away something that has proven itself to be useful often enough?
But that's just me. I have always been conservative with redesigning and been building libraries, even when that meant to store machine code routines on cassette tapes and manually relocating them into a new program.
I have lived with several Zen masters - all of them were cats.
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