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• Is it bad to be the only person supporting software you have developed?

  - by trpt4him

  My employer has a need for a web-based application to manage and share data within the department, with approximately 50-75 possible users. I feel I have the ability to write it for them. I would likely use Python/Django with a MySQL database, so it would be open source. However, I'm the only IT person in my department (our larger organization has a separate IT support staff with which I often work, but not for web development). I want to develop this application, but if I leave in 1-2 years, and someone else has to come in after me and support it, will this be seen as a bad decision? This is assuming all the obvious points -- I will write documentation, I will comment my code, and I will strive to follow good application design principles. But will that be enough? In principle, is it acceptable for one person to develop and support an entire web application? Is this a "do first, then show and ask" kind of situation, or should I be certain it will be adopted by everyone involved first?

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• Parallel Class/Interface Hierarchy with the Facade Design Pattern?

  - by Mike G

  About a third of my code is wrapped inside a Facade class. Note that this isn't a "God" class, but actually represents a single thing (called a Line). Naturally, it delegates responsibilities to the subsystem behind it. What ends up happening is that two of the subsystem classes (Output and Timeline) have all of their methods duplicated in the Line class, which effectively makes Line both an Output and a Timeline. It seems to make sense to make Output and Timeline interfaces, so that the Line class can implement them both. At the same time, I'm worried about creating parallel class and interface structures. You see, there are different types of lines AudioLine, VideoLine, which all use the same type of Timeline, but different types of Output (AudioOutput and VideoOutput, respectively). So that would mean that I'd have to create an AudioOutputInterface and VideoOutputInterface as well. So not only would I have to have parallel class hierarchy, but there would be a parallel interface hierarchy as well. Is there any solution to this design flaw? Here's an image of the basic structure (minus the Timeline class, though know that each Line has-a Timeline): NOTE: I just realized that the word 'line' in Timeline might make is sound like is does a similar function as the Line class. They don't, just to clarify.

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• Thoughts on type aliases/synonyms?

  - by Rei Miyasaka

  I'm going to try my best to frame this question in a way that doesn't result in a language war or list, because I think there could be a good, technical answer to this question. Different languages support type aliases to varying degrees. C# allows type aliases to be declared at the beginning of each code file, and they're valid only throughout that file. Languages like ML/Haskell use type aliases probably as much as they use type definitions. C/C++ are sort of a Wild West, with typedef and #define often being used seemingly interchangeably to alias types. The upsides of type aliasing don't invoke too much dispute: It makes it convenient to define composite types that are described naturally by the language, e.g. type Coordinate = float * float or type String = [Char]. Long names can be shortened: using DSBA = System.Diagnostics.DebuggerStepBoundaryAttribute. In languages like ML or Haskell, where function parameters often don't have names, type aliases provide a semblance of self-documentation. The downside is a bit more iffy: aliases can proliferate, making it difficult to read and understand code or to learn a platform. The Win32 API is a good example, with its DWORD = int and its HINSTANCE = HANDLE = void* and its LPHANDLE = HANDLE FAR* and such. In all of these cases it hardly makes any sense to distinguish between a HANDLE and a void pointer or a DWORD and an integer etc.. Setting aside the philosophical debate of whether a king should give complete freedom to their subjects and let them be responsible for themselves or whether they should have all of their questionable actions intervened, could there be a happy medium that would allow the benefits of type aliasing while mitigating the risk of its abuse? As an example, the issue of long names can be solved by good autocomplete features. Visual Studio 2010 for instance will alllow you to type DSBA in order to refer Intellisense to System.Diagnostics.DebuggerStepBoundaryAttribute. Could there be other features that would provide the other benefits of type aliasing more safely?

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• How does Python compile some its code in C?

  - by Howcan

  I read that some constructs of Python are more efficient because they are compiled in C. https://wiki.python.org/moin/PythonSpeed/PerformanceTips Some of the examples used were map() and filter(). I was wondering how Python is able to do this? It's generally interpreted, so how does some of the code get compiled while another is interpreted - and in a different language? Why not just compile the whole thing?

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• How to implement child-parent aggregation link in C++?

  - by Giorgio

  Suppose that I have three classes P, C1, C2, composition (strong aggregation) relations between P <>- C1 and P <>- C2, i.e. every instance of P contains an instance of C1 and an instance of C2, which are destroyed when the parent P instance is destroyed. an association relation between instances of C1 and C2 (not necessarily between children of the same P). To implement this, in C++ I normally define three classes P, C1, C2, define two member variables of P of type boost::shared_ptr<C1>, boost::shared_ptr<C2>, and initialize them with newly created objects in P's constructor, implement the relation between C1 and C2 using a boost::weak_ptr<C2> member variable in C1 and a boost::weak_ptr<C1> member variable in C2 that can be set later via appropriate methods, when the relation is established. Now, I also would like to have a link from each C1 and C2 object to its P parent object. What is a good way to implement this? My current idea is to use a simple constant raw pointer (P * const) that is set from the constructor of P (which, in turn, calls the constructors of C1 and C2), i.e. something like: class C1 { public: C1(P * const p, ...) : paren(p) { ... } private: P * const parent; ... }; class P { public: P(...) : childC1(new C1(this, ...)) ... { ... } private: boost::shared_ptr<C1> childC1; ... }; Honestly I see no risk in using a private constant raw pointer in this way but I know that raw pointers are often frowned upon in C++ so I was wondering if there is an alternative solution.

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• Everything has an Interface [closed]

  - by Shane

  Possible Duplicate: Do I need to use an interface when only one class will ever implement it? I am taking over a project where every single real class is implementing an Interface. The vast majority of these interfaces are implemented by a single class that share a similar name and the exact same methods (ex: MyCar and MyCarImpl). Almost no 2 classes in the project implement more than the interface that shares its name. I know the general recommendation is to code to an interface rather than an implementation, but isn't this taking it a bit too far? The system might be more flexible in that it is easier to add a new class that behaves very much like an existing class. However, it is significantly harder to parse through the code and method changes now require 2 edits instead of 1. Personally, I normally only create interfaces when there is a need for multiple classes to have the same behavior. I subscribe to YAGNI, so I don't create something unless I see a real need for it. Am I doing it all wrong or is this project going way overboard?

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• What problems can arise from emulating concepts from another languages?

  - by Vandell

  I've read many times on the web that if your language doesn't support some concept, for example, object orientation, or maybe function calls, and it's considered a good practice in this other context, you should do it. The only problem I can see now is that other programmers may find your code too different than the usual, making it hard for them to program. What other problems do you think may arise from this?

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• How to process large files in NetLogo? [closed]

  - by user65597

  I am running into problems in NetLogo with large *.csv / *.txt files. The documents can consist of about 1 million data sets and I need to read them (to eventually create a diagram based on the data). With the most straightforward source code, my program needs about 2 minutes to process these files. How should I approach reading such large data files faster in NetLogo? Is NetLogo even suitable for such tasks (as it seems to be designed more for teaching and learning)?

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• Defining formula through user interface in user form

  - by BriskLabs Pakistan

  I am a student and developing a simple assignment - windows form application in visual studio 2010. The application is suppose to construct formulas as per user requirement. The process: It has to pick data from columns of Microsoft Access database and the user should be able to pick the data by column name like we do in a drop down menu. and create reusable formulas in it ( configure it once and can change it again). followings are column titles from database that can be picked for example. e.g Col -1 : Marks in Maths Col -2 : Total Marks in Maths Col -3 : Marks in science Col -4 : Total marks in science Finally we should be able to construct any formula in the UI like (Col 1 + Col 3 ) / ( col 2 + col 4) = Formula 1 once this is formula is set saved and a name is assigned to it by user. he/she can use the formula and results shall appear in a window below. i.e He would be able to calculate his desired figures (formula) by only manipulating underlying data on the UI layer....choose the data for a period and apply the formula and get the answer Problem: It looks like I have to create an app where rules are set through UI....... this means no stored procedures are required in SQL.... please suggest the right approach.

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• Single or multiple return statements in a function [on hold]

  - by Juan Carlos Coto

  When writing a function that can have several different return values, particularly when different branches of code return different values, what is the cleanest or sanest way of returning? Please note the following are really contrived examples meant only to illustrate different styles. Example 1: Single return def my_function(): if some_condition: return_value = 1 elif another_condition: return_value = 2 else: return_value = 3 return return_value Example 2: Multiple returns def my_function(): if some_condition: return 1 elif another_condition: return 2 else: return 3 The second example seems simpler and is perhaps more readable. The first one, however, might describe the overall logic a bit better (the conditions affect the assignment of the value, not whether it's returned or not). Is the second way preferable to the first? Why?

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• Good book for improving c# skills?

  - by JMarsch

  Hello: I was asked to recommend a good book for a mid-level experienced developer who wants to improve their coding skills (c# developer). I was thinking about: Code Complete: http://www.amazon.com/Code-Complete-Practical-Handbook-Construction/dp/0735619670/ref=sr_1_1?ie=UTF8&qid=1291221928&sr=8-1 The Pragmatic Programmer: http://www.amazon.com/Pragmatic-Programmer-Journeyman-Master/dp/020161622X/ref=sr_1_3?ie=UTF8&qid=1291221928&sr=8-3 or Effective C#: http://www.amazon.com/Effective-Covers-4-0-Specific-Development/dp/0321658701/ref=sr_1_1?s=books&ie=UTF8&qid=1291222038&sr=1-1 What do you think about those? Any other suggestions?

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• Languages like Tcl that have configurable syntax?

  - by boost

  I'm looking for a language that will let me do what I could do with Clipper years ago, and which I can do with Tcl, namely add functionality in a way other than just adding functions. For example in Clipper/(x)Harbour there are commands #command, #translate, #xcommand and #xtranslate that allow things like this: #xcommand REPEAT; => DO WHILE .T. #xcommand UNTIL <cond>; => IF (<cond>); ;EXIT; ;ENDIF; ;ENDDO LOCAL n := 1 REPEAT n := n + 1 UNTIL n > 100 Similarly, in Tcl I'm doing proc process_range {_for_ project _from_ dat1 _to_ dat2 _by_ slice} { set fromDate [clock scan $dat1] set toDate [clock scan $dat2] if {$slice eq "day"} then {set incrementor [expr 24 * 60]} if {$slice eq "hour"} then {set incrementor 60} set method DateRange puts "Scanning from [clock format $fromDate -format "%c"] to [clock format $toDate -format "%c"] by $slice" for {set dateCursor $fromDate} {$dateCursor <= $toDate} {set dateCursor [clock add $dateCursor $incrementor minutes]} { # ... } } process_range for "client" from "2013-10-18 00:00" to "2013-10-20 23:59" by day Are there any other languages that permit this kind of, almost COBOL-esque, syntax modification? If you're wondering why I'm asking, it's for setting up stuff so that others with a not-as-geeky-as-I-am skillset can declare processing tasks.

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• Integrated ads in phone apps - how to avoid wasting battery?

  - by Jarede

  Considering the PCWorld review that came out in March: Free Android Apps Packed with Ads are Major Battery Drains ...Researchers from Purdue University in collaboration with Microsoft claim that third-party advertising in free smartphone apps can be responsible for as much as 65 percent to 75 percent of an app's energy consumption... Is there a best practice for integrating advert support into mobile applications, so as to not drain user battery too much? ...When you fire up Angry Birds on your Android phone, the researchers found that the core gaming component only consumes about 18 percent of total app energy. The biggest battery suck comes from the software powering third-party ads and analytics accounting for 45 percent of total app energy, according to the study... Has anyone invoked better ways of keeping away from the "3G Tail", as the report puts it? Is it better/possible to download a large set of adverts that are cached for a few hours, and using them to populate your ad space, to avoid constant use of the Wi-Fi/3G radios? Are there any best practices for the inclusion of adverts in mobile apps?

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• I want to be a programmer! [closed]

  - by Mohamed Abd El Maged

  I am a doctor. I have a bachelor of medicine and general surgery. I want to change my career and work as a programmer in big companies such as Microsoft, Oracle, ... this is my dream ! I haven't got any degree in IT or Computer science. The question here is: Is it possible to achieve my dream and work as professional programmer in the future? Another question: if applicable, which certifications should I strive to get?

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• How often is seq used in Haskell production code?

  - by Giorgio

  I have some experience writing small tools in Haskell and I find it very intuitive to use, especially for writing filters (using interact) that process their standard input and pipe it to standard output. Recently I tried to use one such filter on a file that was about 10 times larger than usual and I got a Stack space overflow error. After doing some reading (e.g. here and here) I have identified two guidelines to save stack space (experienced Haskellers, please correct me if I write something that is not correct): Avoid recursive function calls that are not tail-recursive (this is valid for all functional languages that support tail-call optimization). Introduce seq to force early evaluation of sub-expressions so that expressions do not grow to large before they are reduced (this is specific to Haskell, or at least to languages using lazy evaluation). After introducing five or six seq calls in my code my tool runs smoothly again (also on the larger data). However, I find the original code was a bit more readable. Since I am not an experienced Haskell programmer I wanted to ask if introducing seq in this way is a common practice, and how often one will normally see seq in Haskell production code. Or are there any techniques that allow to avoid using seq too often and still use little stack space?

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• Why job postings always looking for "rockstars?"

  - by Xepoch

  I have noticed a recent trend in requesting programmers who are rockstars. I get it, they're looking for someone who is really good at what they do. But why (pray) make the reference to a rockstar? Do these companies really want these traits as a real rockstar? Party all night and wake up to take care of quick business in the morning? Substance abuse, Narcissism with celebrity, Compensation well exceeding their management, Excellent at putting on a short-lived show, Entertainment instead of value, 1 hit (project) wonders or single-genre performers, Et cetera What is wrong with Senior or Principal Software Engineer who has an established and proven passion for the business? Rather do we mean quite the opposite, someone who: rolls up the sleeves and gets to work, takes appropriate direction and helps influence teams, programs in lessons' learned and proper practices, provides timely communication to the whole team, can code and understand multiple languages, understands the science and theory behind computation, Is there a trend to diversify the software engineering ranks? How many software rockstars can you hire before your band starts breaking up? Sure, there are lots of folks doing this stuff on their own, maybe even a rare few who do coding for show, but I wager the majority is for business. I don't see ads for rockstar accountants, or rockstar machinists, or rockstart CFOs. What makes the software programmer and their hiring departments lean towards this kind of job title?

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• Mobile Multiplayer games and coping with high latency

  - by spaceOwl

  I'm currently researching regarding a design for an online (realtime) mobile multiplayer game. As such, i'm taking into consideration that latencies (lag) is going to be high (perhaps higher than PC/consoles). I'd like to know if there are ways to overcome this or minimize the issues of high latency? The model i'll be using is peer-to-peer (using Photon cloud to broadcast messages to all other players). How do i deal with a scenario where a message about a local object's state at time t will only get to other players at *t + HUGE_LAG* ?

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• Parallel.For Inconsistency results

  - by ni Gue ???

  I am using VB.net to write a parallel based code. I use Parallel.For to generate pairs of 500 objects or in combination C(500,2) such as the following code; but I found that it didn't always generate all combinations which should be 124750 (shown from variable Counter). No other thread was runing when this code was run. I am using a Win-7 32 Bit desktop with Intel Core i5 CPU [email protected], 3.33 GHz and RAM 2GB. What's wrong with the code and how to solve this problem? Thank You. Dim Counter As Integer = 0 Parallel.For(0, 499, Sub(i) For j As Integer = i + 1 To 499 Counter += 1 Console.Write(i & ":" & j) Next End Sub) Console.Writeline("Iteration number: " & Counter)

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• Can a language support something like "Retry/Fix"?

  - by Aaron Anodide

  I was just wondering if a language could support something like a Retry/Fix block? The answer to this question is probably the reason it's a bad idea or equivalent to something else, but the idea keeps popping into my head. void F() { try { G(); } fix(WrongNumber wn, out int x) { x = 1; } } void G() { int x = 0; retry<int> { if(x != 1) throw new WrongNumber(x); } } After the fix block ran, the retry block would run again...

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• Test driven development - convince me!

  - by Casebash

  I know some people are massive proponents of test driven development. I have used unit tests in the past, but only to test operations that can be tested easily or which I believe will quite possibly be correct. Complete or near complete code coverage sounds like it would take a lot of time. What projects do you use test-driven development for? Do you only use it for projects above a certain size? Should I be using it or not? Convince me!

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• How Does The Maybe Monad Relate To The Option Type?

  - by Onorio Catenacci

  I was doing a presentation on F# and was discussing the Option type when someone in the audience asked me if the Option type is F#'s implementation of the maybe monad. I know that's not the case but I did want to ask how the two concepts are related. I mean it seems to me that an option type might be the result of the operation of a maybe monad but I'm not even sure of that. Would someone elucidate the relationship between the maybe monad and the option type in those functional languages which support it?

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• OpenGL ES 1 Pixel Error?

  - by Beginner001

  I am developing a game on android using OpenGL ES 1.0 for Android OS. It is a 2d game using a simple Orthographic projection and textures for the sprites. One of these textures has a small line (it looks like 1 pixel) all the way across the top that has the same colors as the bottom 1-pixel line of the texture. It is almost as if the bottom line of the image raster was copied and pasted as the top line as well. Is anyone familiar with this type of error? What could the problem be?

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• How do references work in R?

  - by djechlin

  I'm finding R confusing because it has such a different notion of reference than I am used to in languages like C, Java, Javascript... Ruby, Python, C++, well, pretty much any language I have ever programmed in ever. So one thing I've noticed is variable names are not irrelevant when passing them to something else. The reference can be part of the data. e.g. per this tutorial a <- factor(c("A","A","B","A","B","B","C","A","C")) results <- table(a) Leads to $a showing up as an attribute as $dimnames$a. We've also witnessed that calling a function like a <- foo(alpha=1, beta=2) can create attributes in a of names alpha and beta, or it can assign or otherwise compute on 1 and 2 to properties already existing. (Not that there's a computer science distinction here - it just doesn't really happen in something like Javascript, unless you want to emulate it by passing in the object and use key=value there.) Functions like names(...) return lvalues that will affect the input of them. And the one that most got me is this. x <- c(3, 5, 1, 10, 12, 6) y = x[x <= 5] x[y] <- 0 is different from x <- c(3, 5, 1, 10, 12, 6) x[x <= 5] <- 0 Color me confused. Is there a consistent theory for what's going on here?

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• Why Nodes.js being that "unique"?

  - by Adrian Shum

  Recently years there are lots of praise to Nodes.js. I am not a developer that have much exposure on network application. From my bare understanding of Nodes.js, its strength is: We are having only on thread handling multiple connections, providing a event-based architecture. However, for example in Java, what if I am having only one thread, using NIO/AIO (which is non-blocking APIs from my bare understanding), and handle multiple connections using that thread, and I provide an event-based architecture to implement the data handling logic (shouldn't be that difficult by providing some callback etc) ? Given JVM being a even more mature VM than V8 (I expect it run faster too), and event-based handling architecture seems not something difficult to create. I am not sure why Nodes.js is attracting so much attention. Did I miss some important points?

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• Learning good OOP design & unlearning some bad habits

  - by Nick

  I have been mostly a C programmer so far in my career with knowledge of C++. I rely on C++ mostly for the convenience STL provides and I hardly ever focus on good design practices. As I have started to look for a new job position, this bad habit of mine has come back to haunt me. During the interviews, I have been asked to design a problem (like chess, or some other scenario) using OOP and I doing really badly at that (I came to know this through feedback from one interview). I tried to google stuff and came up with so many opinions and related books that I don't know where to begin. I need a good through introduction to OOP design with which I can learn practical design, not just theory. Can you point me to any book which meets my requirements ? I prefer C++, but any other language is fine as long as I can pick-up good practices. Also, I know that books can only go so far. I would also appreciate any good practice project ideas that helped you learn and improve your OOP concepts. Thanks.

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