Search Results

Search found 22161 results on 887 pages for 'idl programming language'.

Page 240/887 | < Previous Page | 236 237 238 239 240 241 242 243 244 245 246 247  | Next Page >

• Haskell Cons Operator (:)

  - by Carson Myers

  I am really new to Haskell (Actually I saw "Real World Haskell" from O'Reilly and thought "hmm, I think I'll learn functional programming" yesterday) and I am wondering: I can use the construct operator to add an item to the beginning of a list: 1 : [2,3] [1,2,3] I tried making an example data type I found in the book and then playing with it: --in a file data BillingInfo = CreditCard Int String String | CashOnDelivery | Invoice Int deriving (Show) --in ghci $ let order_list = [Invoice 2345] $ order_list [Invoice 2345] $ let order_list = CashOnDelivery : order_list $ order_list [CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, ...- etc... it just repeats forever, is this because it uses lazy evaluation? -- EDIT -- okay, so it is being pounded into my head that let order_list = CashOnDelivery:order_list doesn't add CashOnDelivery to the original order_list and then set the result to order_list, but instead is recursive and creates an infinite list, forever adding CashOnDelivery to the beginning of itself. Of course now I remember that Haskell is a functional language and I can't change the value of the original order_list, so what should I do for a simple "tack this on to the end (or beginning, whatever) of this list?" Make a function which takes a list and BillingInfo as arguments, and then return a list? -- EDIT 2 -- well, based on all the answers I'm getting and the lack of being able to pass an object by reference and mutate variables (such as I'm used to)... I think that I have just asked this question prematurely and that I really need to delve further into the functional paradigm before I can expect to really understand the answers to my questions... I guess what i was looking for was how to write a function or something, taking a list and an item, and returning a list under the same name so the function could be called more than once, without changing the name every time (as if it was actually a program which would add actual orders to an order list, and the user wouldn't have to think of a new name for the list each time, but rather append an item to the same list).

  Read the article

• Is learning C++ a good idea?

  - by chang

  The more I hear and read about C++ (e.g. this: http://lwn.net/Articles/249460/), I get the impression, that I'd waste my time learning C++. I some wrote network routing algorithm in C++ for a simulator, and it was a pain (as expected, especially coming from a perl/python/Java background ...). I'm never happy about giving up on some technology, but I would be happy, if I could limit my knowledge of C-family languages to just C, C# and Objective-C (even OS Xs Cocoa, which is huge and takes a lot of time to learn looks like joy compared to C++ ...). Do I need to consider myself dumb or unwilling, just because I'm not partial to the pain involved learning this stuff? Technologies advance and there will be options other than C++, when deciding on implementation languages, or not? And for speed: If speed were that critical, I'd go for a plain C implementation instead, or write C extensions for much more productive languages like ruby or python ... The one-line version of the above: Will C++ stay such a relevant language that every committed programmer should be familiar with it? [ edit / thank you very much for your interesting and useful answers so far .. ] [ edit / .. i am accepting the top-rated answer; thanks again for all answers! ]

  Read the article

• Are there any code critique sites or similar resources?

  - by Ukko

  I have noticed when people post example code illustrating some issue that they are having often they will gather a number of comments addressing the quality of the code they presented and not the actual problem asked. This is very helpful--if not well directed. Often, this is wasted effort since the asker is often not receptive and the code is often chopped down to something small to post leaving lots of rough edges. In the old days you would see people asking questions like this on comp.lang.lisp and other parts of the comp.lang hierarchy. But that bit of the net kind of sank into the sewers of neglect. Is there a comparable one-stop-shop today? I am partially asking for selfish reasons, I know how to write good idiomatic C, Lisp, O'Caml, and Java code. But I learned C++ pre-template and STL, those rusty skills are not really applicable to today's C++. I have picked up languages like Scala in a vacuum and get by, but am I really doing it correctly? There are so many ways you can abuse a language, I am currently working against a codebase of Fortran written in C, and I recognize and loathe the "that guy" who wrote it. I don't want to be someone else's "that guy" if I can help it. Just because it works does not mean that one did not totally miss the boat on how it should have been done. Do you seek out this type of critique? If so how, where and why? What types of benefits do you derive from it? How about abuse and trolls?

  Read the article

• How do you use stl's functions like for_each?

  - by thomas-gies

  I started using stl containers because they came in very handy when I needed functionality of a list, set and map and had nothing else available in my programming environment. I did not care much about the ideas behind it. STL documentations were only interesting up to the point where it came to functions, etc. Then I skipped reading and just used the containers. But yesterday, still being relaxed from my holidays, I just gave it a try and wanted to go a bit more the stl way. So I used the transform function (can I have a little bit of applause for me, thank you). From an academic point of view it really looked interesting and it worked. But the thing that boroughs me is that if you intensify the use of those functions, you need 10ks of helper classes for mostly everything you want to do in your code. The hole logic of the program is sliced in tiny pieces. This slicing is not the result of god coding habits. It's just a technical need. Something, that makes my life probably harder not easier. And I learned the hard way, that you should always choose the simplest approach that solves the problem at hand. And I can't see what, for example, the for_each function is doing for me that justifies the use of a helper class over several simple lines of code that sit inside a normal loop so that everybody can see what is going on. I would like to know, what you are thinking about my concerns? Did you see it like I do when you started working this way and have changed your mind when you got used to it? Are there benefits that I overlooked? Or do you just ignore this stuff as I did (and will go an doing it, probably). Thanks. PS: I know that there is a real for_each loop in boost. But I ignore it here since it is just a convenient way for my usual loops with iterators I guess.

  Read the article

• Are there any downsides in using C++ for network daemons?

  - by badcat

  Hey guys! I've been writing a number of network daemons in different languages over the past years, and now I'm about to start a new project which requires a new custom implementation of a properitary network protocol. The said protocol is pretty simple - some basic JSON formatted messages which are transmitted in some basic frame wrapping to have clients know that a message arrived completely and is ready to be parsed. The daemon will need to handle a number of connections (about 200 at the same time) and do some management of them and pass messages along, like in a chat room. In the past I've been using mostly C++ to write my daemons. Often with the Qt4 framework (the network parts, not the GUI parts!), because that's what I also used for the rest of the projects and it was simple to do and very portable. This usually worked just fine, and I didn't have much trouble. Being a Linux administrator for a good while now, I noticed that most of the network daemons in the wild are written in plain C (of course some are written in other languages, too, but I get the feeling that 80% of the daemons are written in plain C). Now I wonder why that is. Is this due to a pure historic UNIX background (like KISS) or for plain portability or reduction of bloat? What are the reasons to not use C++ or any "higher level" languages for things like daemons? Thanks in advance! Update 1: For me using C++ usually is more convenient because of the fact that I have objects which have getter and setter methods and such. Plain C's "context" objects can be a real pain at some point - especially when you are used to object oriented programming. Yes, I'm aware that C++ is a superset of C, and that C code is basically C++. But that's not the point. ;)

  Read the article

• Ruby: counters, counting and incrementing

  - by Shyam

  Hi, If you have seen my previous questions, you'd already know I am a big nuby when it comes to Ruby. So, I discovered this website which is intended for C programming, but I thought whatever one can do in C, must be possible in Ruby (and more readable too). The challenge is to print out a bunch of numbers. I discovered this nifty method .upto() and I used a block (and actually understanding its purpose). However, in IRb, I got some unexpected behavior. class MyCounter def run 1.upto(10) { |x| print x.to_s + " " } end end irb(main):033:0> q = MyCounter.new => #<MyCounter:0x5dca0> irb(main):034:0> q.run 1 2 3 4 5 6 7 8 9 10 => 1 I have no idea where the = 1 comes from :S Should I do this otherwise? I am expecting to have this result: 1 2 3 4 5 6 7 8 9 10 Thank you for your answers, comments and feedback!

  Read the article

• Is it OK to write code after [super dealloc]? (Objective-C)

  - by Richard J. Ross III

  I have a situation in my code, where I cannot clean up my classes objects without first calling [super dealloc]. It is something like this: // Baseclass.m @implmentation Baseclass ... -(void) dealloc { [self _removeAllData]; [aVariableThatBelongsToMe release]; [anotherVariableThatBelongsToMe release]; [super dealloc]; } ... @end This works great. My problem is, when I went to subclass this huge and nasty class (over 2000 lines of gross code), I ran into a problem: when I released my objects before calling [super dealloc] I had zombies running through the code that were activated when I called the [self _removeAllData] method. // Subclass.m @implementation Subclass ... -(void) deallloc { [super dealloc]; [someObjectUsedInTheRemoveAllDataMethod release]; } ... @end This works great, and It didn't require me to refactor any code. My question Is this: Is it safe for me to do this, or should I refactor my code? Or maybe autorelease the objects? I am programming for iPhone if that matters any.

  Read the article

• Freelance web hosting - what are good LAMP choices?

  - by tkotitan

  I think it's best if I ask this question with an example scenario. Let's say your mom-and-pop local hardware store has never had a website, and they want you, the freelance developer to build them a website. You have all the skills to run a LAMP setup and admin a system, so the difficult question you ask yourself is - where will I host it? As you aren't going to host it out of the machine in your apartment. Let's say you want to be able to customize your own system, install the version of PHP you want, and manage your own database. Perhaps the best kind of hosting is to get a virtual machine so you can customize the system as you see fit. But this essentially a "set it and forget it" site you make, bill by the hour for, and then are done. In other words, the hosting should not be an issue. Given the requirements of hosting a website: Unlimited growth potential needing good amounts of bandwidth to handle visitors Wide range of system and programming options allowing it to be portable Relatively cheap (not necessarily the cheapest) or reasonable scaling cost Reliable hosting with good support Hosted entirely on the host company's hardware Who would you pick to host this website? Yes I am asking for a business/company recommendation. Is there a clear answer for this scenario, or a good source that can reliably give the current answer? I know there are all kinds of schemes out there. I'm just wondering if any one company fills the bill for freelancers and stands out in such a crowded market.

  Read the article

• Help! I'm a Haskell Newbie

  - by Darknight

  I've only just dipped my toe in the world of Haskell as part of my journey of programming enlightenment (moving on from, procedural to OOP to concurrent to now functional). I've been trying an online Haskell Evaluator. However I'm now stuck on a problem: Create a simple function that gives the total sum of an array of numbers. In a procedural language this for me is easy enough (using recursion) (c#) : private int sum(ArrayList x, int i) { if (!(x.Count < i + 1)) { int t = 0; t = x.Item(i); t = sum(x, i + 1) + t; return t; } } All very fine however my failed attempt at Haskell was thus: let sum x = x+sum in map sum [1..10] this resulted in the following error (from that above mentioned website): Occurs check: cannot construct the infinite type: a = a -> t Please bear in mind I've only used Haskell for the last 30 minutes! I'm not looking simply for an answer but a more explanation of it. Thanks in advanced.

  Read the article

• Alter a function as a parameter before evaluating it in R?

  - by Shane

  Is there any way, given a function passed as a parameter, to alter its input parameter string before evaluating it? Here's pseudo-code for what I'm hoping to achieve: test.func <- function(a, b) { # here I want to alter the b expression before evaluating it: b(..., val1=a) } Given the function call passed to b, I want to add in a as another parameter without needing to always specify ... in the b call. So the output from this test.func call should be: test.func(a="a", b=paste(1, 2)) "1" "2" "a" Edit: Another way I could see doing something like this would be if I could assign the additional parameter within the scope of the parent function (again, as pseudo-code); in this case a would be within the scope of t1 and hence t2, but not globally assigned: t2 <- function(...) { paste(a=a, ...) } t1 <- function(a, b) { local( { a <<- a; b } ) } t1(a="a", b=t2(1, 2)) This is somewhat akin to currying in that I'm nesting the parameter within the function itself. Edit 2: Just to add one more comment to this: I realize that one related approach could be to use "prototype-based programming" such that things would be inherited (which could be achieved with the proto package). But I was hoping for a easier way to simply alter the input parameters before evaluating in R.

  Read the article

• How can I implement a splay tree that performs the zig operation last, not first?

  - by Jakob

  For my Algorithms & Data Structures class, I've been tasked with implementing a splay tree in Haskell. My algorithm for the splay operation is as follows: If the node to be splayed is the root, the unaltered tree is returned. If the node to be splayed is one level from the root, a zig operation is performed and the resulting tree is returned. If the node to be splayed is two or more levels from the root, a zig-zig or zig-zag operation is performed on the result of splaying the subtree starting at that node, and the resulting tree is returned. This is valid according to my teacher. However, the Wikipedia description of a splay tree says the zig step "will be done only as the last step in a splay operation" whereas in my algorithm it is the first step in a splay operation. I want to implement a splay tree that performs the zig operation last instead of first, but I'm not sure how it would best be done. It seems to me that such an algorithm would become more complex, seeing as how one needs to find the node to be splayed before it can be determined whether a zig operation should be performed or not. How can I implement this in Haskell (or some other functional language)?

  Read the article

• Generating a python file

  - by fema

  Hi! I'm havin issues with python (imo python itself is an issue). I have a txt file, it contains a custom language and I have to translate it to a working python code. The input: import sys n = int(sys.argv[1]) ;;print "Beginning of the program!" LOOP i in range(1,n) {print "The number:";;print i} BRANCH n < 5 {print n ;;print "less than 5"} The wanted output looks exactly like this: import sys n = int(sys.argv[1]) print "Beginning of the program!" for i in range(1,n) : print "The number:" print i if n < 5 : print n print "less than 5" The name of the input file is read from parameter. The out file is out.py. In case of a wrong parameter, it gives an error message. The ;; means a new line. When I tried to do it, I made an array, I read all the lines into it, split by " ". Then I wanted to strip it from the marks I don't need. I made 2 loops, one for the lines, one for the words. So then I started to replace the things. Everything went fine until it came to the } mark. It finds it, but it can not replace or strip it. I have no more idea what to do. Could someone help me, please? Thanks in advance!

  Read the article

• What's the *right* way to handle a POST in FP?

  - by Malvolio

  I'm just getting started with FP and I'm using Scala, which may not be the best way, since I can always fall back to an imperative style if the going gets tough. I'd just rather not. I've got a very specific question that points to a broader lacuna in my understanding of FP. When a web application is processing a GET request, the user wants information that already exists on the web-site. The application only has to process and format the data in some way. The FB way is clear. When a web application is processing a POST request, the user wants change the information held on the site. True, the information is not typically held in application variables, it's in a database or a flat-file, but still, I get the feeling I'm not grokking FP properly. Is there a pattern for handling updates to static data in an FP language? My vague picture of this is that the application is handed the request and the then-current site state. The application does its thing and returns the new site-state. If the current site-state hasn't changed since the application started, the new state becomes the current state and the reply is sent back to the browser (this is my dim image of Clojure's style); if the current state has been changed (by another thread, well, something else happens ...

  Read the article

• Parallelize or vectorize all-against-all operation on a large number of matrices?

  - by reve_etrange

  I have approximately 5,000 matrices with the same number of rows and varying numbers of columns (20 x ~200). Each of these matrices must be compared against every other in a dynamic programming algorithm. In this question, I asked how to perform the comparison quickly and was given an excellent answer involving a 2D convolution. Serially, iteratively applying that method, like so list = who('data_matrix_prefix*') H = cell(numel(list),numel(list)); for i=1:numel(list) for j=1:numel(list) if i ~= j eval([ 'H{i,j} = compare(' char(list(i)) ',' char(list(j)) ');']); end end end is fast for small subsets of the data (e.g. for 9 matrices, 9*9 - 9 = 72 calls are made in ~1 s). However, operating on all the data requires almost 25 million calls. I have also tried using deal() to make a cell array composed entirely of the next element in data, so I could use cellfun() in a single loop: # who(), load() and struct2cell() calls place k data matrices in a 1D cell array called data. nextData = cell(k,1); for i=1:k [nextData{:}] = deal(data{i}); H{:,i} = cellfun(@compare,data,nextData,'UniformOutput',false); end Unfortunately, this is not really any faster, because all the time is in compare(). Both of these code examples seem ill-suited for parallelization. I'm having trouble figuring out how to make my variables sliced. compare() is totally vectorized; it uses matrix multiplication and conv2() exclusively (I am under the impression that all of these operations, including the cellfun(), should be multithreaded in MATLAB?). Does anyone see a (explicitly) parallelized solution or better vectorization of the problem?

  Read the article

• How can I write simulations in Erlang?

  - by rick

  Hi guys, I want to do some numerical stuff in Erlang like this: You've got an array with the following values: [2,3,4] In each iteration, you calculate 0.1 * [n-1] + 0.7 *[n] + 0.2 * [n+1] This becomes the new [n]. If n == 0 then [n-1] = 0. If [n] == length of array then [n] = 0. So I try an example: [2,3,4] calculations: 0.1 * 0 + 0.7 * 2 + 0.2 * 3 = 2 0.1 * 2 + 0.7 * 3 + 0.2 * 4 = 3.1 0.1 * 3 + 0.7 * 4 + 0.2 * 0 = 3.1 So [2,3,4] becomes to [2, 3.1, 3.1] after one iteration. I know how to write this in a non-functional language like C. But I have difficulties to imagine, how this could be done in Erlang. I found some tutorials on how you read a file to a list. So this is not the problem. How can I spawn different Erlang processes that each process has one element of the list? How can I do calculations by communicating with 'the neighbors', so that the neighbors know where their neigbors are generically, without specifying each? How can I collect the data into a list? Eventually, is it possible to solve that problem in Erlang at all? Thanks for your help.

  Read the article

• Help Needed Finding a Programmer

  - by ssean

  Good Morning, I am trying to find a programmer to code a piece of custom software for my business. I plan on using this software to manage my business, and possibly sell it to other companies (in the same industry) at a later date. I've never hired a programmer before, so I'm not sure what to expect or where to begin. I know exactly what features I need, and how I want it laid out, I just need someone who can take my ideas and make it happen. This software will be used to manage customer information, and keep track of orders. What I think I need: * SQL Server or similar database that will be located at our office. * Desktop Application, that connects via LAN to the database server (cannot be browser based) * Multiple User Support (Simultaneous users accesing the system) * Needs to be scalable (currently we have 5 employees, but who knows what the future will bring) * Multi-Platform Support (Windows, Linux) I posted a job offer through elance, which seems to raise more questions than answers. How do I decide what language(s) will work best for my situation? (I have received offers for C#, Eclipse, .NET, Powerbuilder, etc. - I want to make sure that I choose the best one now, so I don't run into problems later) Does the programmer hold any rights to the software? (I plan to offer the software for sale at a later date) Any help or insight would be appreciated, and I'd be happy to clarify anything if it helps. Thanks in advance!

  Read the article

• Does using functional languages help against computing values repeatedly?

  - by sharptooth

  Consider a function f(x,y): f(x,0) = x*x; f(0,y) = y*(y + 1); f(x,y) = f(x,y-1) + f(x-1,y); If one tries to implement that recursively in some language like C++ he will encounter a problem. Suppose the function is first called with x = x0 and y = y0. Then for any pair (x,y) where 0 <= x < x0 and 0 <= y < y0 the intermediate values will be computed multiple times - recursive calls will form a huge tree in which multiple leaves will in fact contain the same pairs (x,y). For pairs (x,y) where x and y are both close to 0 values will be computed numerous times. For instance, I tested a similar function implemented in C++ - for x=20 and y=20 its computation takes about 4 hours (yes, four Earth hours!). Obviously the implementation can be rewritten in such way that repeated computation doesn't occur - either iteratively or with a cache table. The question is: will functional languages perform any better and avoid repeated computations when implementing a function like above recursively?

  Read the article

• SYN receives RST,ACK very frequently

  - by user1289508

  Hi Socket Programming experts, I am writing a proxy server on Linux for SQL Database server running on Windows. The proxy is coded using bsd sockets and in C, and it is working just fine. When I use a database client (written in JAVA, and running on a Linux box) to fire queries (with a concurrency of 100 or more) directly to the Database server, not experiencing connection resets. But through my proxy I am experiencing many connection resets. Digging deeper I came to know that connection from 'DB client' to 'Proxy' always succeeds but when the 'Proxy' tries to connect to the DB server the connection fails, due to the SYN packet getting RST,ACK. That was to give some background. The question is : Why does sometimes SYN receives RST,ACK? 'DB client(linux)' to 'Server(windows)' ---- Works fine 'DB client(linux) to 'Proxy(Linux)' to 'Server(windows)' ----- problematic I am aware that this can happen in "connection refused" case but this definitely is not that one. SYN flooding might be another scenario, but that does not explain fine behavior while firing to Server directly. I am suspecting some socket option setting may be required, that the client does before connecting and my proxy does not. Please put some light on this. Any help (links or pointers) is most appreciated. Additional info: Wrote a C client that does concurrent connections, which takes concurrency as an argument. Here are my observations: - At 5000 concurrency and above, some connects failed with 'connection refused'. - Below 2000, it works fine. But the actual problem is observed even at a concurrency of 100 or more. Note: The problem is time dependent sometimes it never comes at all and sometimes it is very frequent and DB client (directly to server) works fine at all times .

  Read the article

• Finding k elements of length-n list that sum to less than t in O(nlogk) time

  - by tresbot

  This is from Programming Pearls ed. 2, Column 2, Problem 8: Given a set of n real numbers, a real number t, and an integer k, how quickly can you determine whether there exists a k-element subset of the set that sums to at most t? One easy solution is to sort and sum the first k elements, which is our best hope to find such a sum. However, in the solutions section Bentley alludes to a solution that takes nlog(k) time, though he gives no hints for how to find it. I've been struggling with this; one thought I had was to go through the list and add all the elements less than t/k (in O(n) time); say there are m1 < k such elements, and they sum to s1 < t. Then we are left needing k - m1 elements, so we can scan through the list again in O(n) time looking for all elements less than (t - s1)/(k - m1). Add in again, to get s2 and m2, then again if m2 < k, look for all elements less than (t - s2)/(k - m2). So: def kSubsetSumUnderT(inList, k, t): outList = [] s = 0 m = 0 while len(outList) < k: toJoin = [i for i in inList where i < (t - s)/(k - m)] if len(toJoin): if len(toJoin) >= k - m: toJoin.sort() if(s0 + sum(toJoin[0:(k - m - 1)]) < t: return True return False outList = outList + toJoin s += sum(toJoin) m += len(toJoin) else: return False My intuition is that this might be the O(nlog(k)) algorithm, but I am having a hard time proving it to myself. Thoughts?

  Read the article

• SEO non-English domain name advice

  - by Dominykas Mostauskis

  I'm starting a website, that is meant for a non-English region, using an alphabet that is a bit different than that of English. Current plan is as follows. The website name, and the domain name, will be in the local language (not English); however, domain name will be spelled in the English alphabet, while the website's title will be the same word(s), but spelled properly with accents. E.g.: 'www.litterat.fr' and 'Littérat'. Does the difference between domain name and website name character use influence the site's SEO? Is it better, SEO-wise, to choose a name that can be spelled the same way in the English alphabet? From my experience, when searching online, invariably, the English alphabet is used, no matter the language, so people will still be searching 'litterat' (without accents and such). Edit: To sum up: Things have been said about IDN (Internationalized domain name). To make it simple, they are second-level domain names that contain language specific characters (LSP)(e.g. www.café.fr). Here you can check what top-level domains support what LSPs. Check initall's answer for more info on using LSPs in paths and queries. To answer my question about how and if search engines relate keywords spelled with and without language specific characters: Google can potentially tell that series and séries is the same keyword. However, (most relevant for words that are spelled differently across languages and have different meanings, like séries), for Google to make the connection (or lack thereof) between e and é, it has to deduce two things: Language that you are searching in. Language of your query. You can specify it manually through Advanced search or it guesses it, sometimes. I presume it can guess it wrong too. The more keywords specific to this language you use the higher Google's chance to guess the language. Language of the crawled document, against which the ASCII version of the word will be compared (in this example – series). Again, check initall's answer for how to help Google in understanding what language your document is in. Once it has that it can tell whether or not these two spellings should be treated as the same keyword. Google has to understand that even though you're not using french (in this example) specific characters, you're searching in French. The reason why I used the french word séries in this example, is that it demonstrates this very well. You have it in French and you have it in English without the accent. So if your search query is ambiguous like our series, unless Google has something more to go on, it will presume that there's no correlation between your search and séries in French documents. If you augment your query to series romantiques (try it), Google will understand that you're searching in French and among your results you'll see séries as well. But this does not always work, you should test it out with your keywords first. For example, if you search series francaises, it will associate francaises with françaises, but it will not associate series with séries. It depends on the words. Note: worth stressing that this problem is very relevant to words that, written in plain ASCII, might have some other meanings in other languages, it is less relevant to words that can be, by a distinct margin, just some one language. Tip: I've noticed that sometimes even if my non-accented search query doesn't get associated with the properly spelled word in a document (especially if it's the title or an important keyword in the doc), it still comes up. I followed the link, did a Ctrl-F search for my non-accented search query and found nothing, then checked the meta-tags in the source and you had the page's title in both accented and non-accented forms. So if you have meta-tags that can be spelled with language specific characters and without, put in both. Footnote: I hope this helps. If you have anything to add or correct, go ahead.

  Read the article

• Autoloading Development or Production configs (best practices)

  - by Xeoncross

  When programming sites you usually have one set of config files for the development environment and another set for the production server (or one file with both settings). I am assuming all projects should be handled by version control like git or svn. Manual file transfers (like FTP) is wrong on so many levels. How you enable/disable the correct settings (so that your system knows which ones to use) is a problem for me. Each system I work on just kind of jimmy-rigs a solution. Below are the 3 methods I know of and I am hoping that someone can submit a more elegant solutions. 1) File Based The system loads a folder structure based on the URL requested. /site.com /site.fakeTLD /lib index.php For example, if the url is http://site.com then the system loads the production config files located in the site.com folder. However, if I'm working on the site locally I visit http://site.fakeTLD to work on the local copy of the site. To setup this I edit my hosts file and add site.fakeTLD to point to my own computer (127.0.0.1/localhost) and then create a vhost in apache. So now I can work on the codebase locally and then push to the server without any trouble. The problem is that this is susceptible to a "host" injection attack. So someone loading site.com could set the host to site.fakeTLD and then the system would load my development config files instead of production. 2) Config Based The config files contain on section for development - and one for production. The problem is that each time you go to push your changes to the repo you have to edit the file to specify which set of config options should be used. $use = 'production'; //'development'; This leaves the repo open to human error should one of the developers forget to enable the right setting. 3) File System Check Based All the development machines have an extra empty file called "development.txt" or something. Each time the system loads it checks for this file - if found then it knows it is in development mode - if missing then it knows it is in production mode. Since the file is NEVER ADDED to the repo then it will never be pushed (and checked out) on the production machine. However, this just doesn't feel right and causes a slight slow down since all filesystem checks are slow. Is there anyway that the server can auto-detect wither to use the development or production configs?

  Read the article

• J: Self-reference in bubble sort tacit implementation

  - by Yasir Arsanukaev

  Hello people! Since I'm beginner in J I've decided to solve a simple task using this language, in particular implementing the bubblesort algorithm. I know it's not idiomatically to solve such kind of problem in functional languages, because it's naturally solved using array element transposition in imperative languages like C, rather than constructing modified list in declarative languages. However this is the code I've written: (((<./@(2&{.)), $:@((>./@(2&{.)),2&}.)) ^: (1<#)) ^: # Let's apply it to an array: (((<./@(2&{.)), $:@((>./@(2&{.)),2&}.)) ^: (1<#)) ^: # 5 3 8 7 2 2 3 5 7 8 The thing that confuses me is $: referring to the statement within the outermost parentheses. Help says that: $: denotes the longest verb that contains it. The other book (~ 300 KiB) says: 3+4 7 5*20 100 Symbols like + and * for plus and times in the above phrases are called verbs and represent functions. You may have more than one verb in a J phrase, in which case it is constructed like a sentence in simple English by reading from left to right, that is 4+6%2 means 4 added to whatever follows, namely 6 divided by 2. Let's rewrite my code snippet omitting outermost ()s: ((<./@(2&{.)), $:@((>./@(2&{.)),2&}.)) ^: (1<#) ^: # 5 3 8 7 2 2 3 5 7 8 Reuslts are the same. I couldn't explain myself why this works, why only ((<./@(2&{.)), $:@((>./@(2&{.)),2&}.)) ^: (1<#) is treated as the longest verb for $: but not the whole expression ((<./@(2&{.)), $:@((>./@(2&{.)),2&}.)) ^: (1<#) ^: # and not just (<./@(2&{.)), $:@((>./@(2&{.)),2&}.), because if ((<./@(2&{.)), $:@((>./@(2&{.)),2&}.)) ^: (1<#) is a verb, it should also form another verb after conjunction with #, i. e. one might treat the whole sentence (first snippet) as a verb. Probably there's some limit for the verb length limited by one conjunction. Look at the following code (from here): factorial =: (* factorial@<:) ^: (1&<) factorial 4 24 factorial within expression refers to the whole function, i. e. (* factorial@<:) ^: (1&<). Following this example I've used a function name instead of $:: bubblesort =: (((<./@(2&{.)), bubblesort@((>./@(2&{.)),2&}.)) ^: (1<#)) ^: # bubblesort 5 3 8 7 2 2 3 5 7 8 I expected bubblesort to refer to the whole function, but it doesn't seem true for me since the result is correct. Also I'd like to see other implementations if you have ones, even slightly refactored. Thanks.

  Read the article

• What is the best algorithm for this problem?

  - by mark

  What is the most efficient algorithm to solve the following problem? Given 6 arrays, D1,D2,D3,D4,D5 and D6 each containing 6 numbers like: D1[0] = number D2[0] = number ...... D6[0] = number D1[1] = another number D2[1] = another number .... ..... .... ...... .... D1[5] = yet another number .... ...... .... Given a second array ST1, containing 1 number: ST1[0] = 6 Given a third array ans, containing 6 numbers: ans[0] = 3, ans[1] = 4, ans[2] = 5, ......ans[5] = 8 Using as index for the arrays D1,D2,D3,D4,D5 and D6, the number that goes from 0, to the number stored in ST1[0] minus one, in this example 6, so from 0 to 6-1, compare each res array against each D array My algorithm so far is: I tried to keep everything unlooped as much as possible. EML := ST1[0] //number contained in ST1[0] EML1 := 0 //start index for the arrays D While EML1 < EML if D1[ELM1] = ans[0] goto two if D2[ELM1] = ans[0] goto two if D3[ELM1] = ans[0] goto two if D4[ELM1] = ans[0] goto two if D5[ELM1] = ans[0] goto two if D6[ELM1] = ans[0] goto two ELM1 = ELM1 + 1 return 0 //bad row of numbers, if while ends two: EML1 := 0 start index for arrays Ds While EML1 < EML if D1[ELM1] = ans[1] goto two if D2[ELM1] = ans[1] goto two if D3[ELM1] = ans[1] goto two if D4[ELM1] = ans[1] goto two if D5[ELM1] = ans[1] goto two if D6[ELM1] = ans[1] goto two ELM1 = ELM1 + 1 return 0 three: EML1 := 0 start index for arrays Ds While EML1 < EML if D1[ELM1] = ans[2] goto two if D2[ELM1] = ans[2] goto two if D3[ELM1] = ans[2] goto two if D4[ELM1] = ans[2] goto two if D5[ELM1] = ans[2] goto two if D6[ELM1] = ans[2] goto two ELM1 = ELM1 + 1 return 0 four: EML1 := 0 start index for arrays Ds While EML1 < EML if D1[ELM1] = ans[3] goto two if D2[ELM1] = ans[3] goto two if D3[ELM1] = ans[3] goto two if D4[ELM1] = ans[3] goto two if D5[ELM1] = ans[3] goto two if D6[ELM1] = ans[3] goto two ELM1 = ELM1 + 1 return 0 five: EML1 := 0 start index for arrays Ds While EML1 < EML if D1[ELM1] = ans[4] goto two if D2[ELM1] = ans[4] goto two if D3[ELM1] = ans[4] goto two if D4[ELM1] = ans[4] goto two if D5[ELM1] = ans[4] goto two if D6[ELM1] = ans[4] goto two ELM1 = ELM1 + 1 return 0 six: EML1 := 0 start index for arrays Ds While EML1 < EML if D1[ELM1] = ans[0] return 1 //good row of numbers if D2[ELM1] = ans[0] return 1 if D3[ELM1] = ans[0] return 1 if D4[ELM1] = ans[0] return 1 if D5[ELM1] = ans[0] return 1 if D6[ELM1] = ans[0] return 1 ELM1 = ELM1 + 1 return 0 As language of choice, it would be pure c

  Read the article

• Variable sized packet structs with vectors

  - by Rev316

  Lately I've been diving into network programming, and I'm having some difficulty constructing a packet with a variable "data" property. Several prior questions have helped tremendously, but I'm still lacking some implementation details. I'm trying to avoid using variable sized arrays, and just use a vector. But I can't get it to be transmitted correctly, and I believe it's somewhere during serialization. Now for some code. Packet Header class Packet { public: void* Serialize(); bool Deserialize(void *message); unsigned int sender_id; unsigned int sequence_number; std::vector<char> data; }; Packet ImpL typedef struct { unsigned int sender_id; unsigned int sequence_number; std::vector<char> data; } Packet; void* Packet::Serialize(int size) { Packet* p = (Packet *) malloc(8 + 30); p->sender_id = htonl(this->sender_id); p->sequence_number = htonl(this->sequence_number); p->data.assign(size,'&'); //just for testing purposes } bool Packet::Deserialize(void *message) { Packet *s = (Packet*)message; this->sender_id = ntohl(s->sender_id); this->sequence_number = ntohl(s->sequence_number); this->data = s->data; } During execution, I simply create a packet, assign it's members, and send/receive accordingly. The above methods are only responsible for serialization. Unfortunately, the data never gets transferred. Couple of things to point out here. I'm guessing the malloc is wrong, but I'm not sure how else to compute it (i.e. what other value it would be). Other than that, I'm unsure of the proper way to use a vector in this fashion, and would love for someone to show me how (code examples please!) :) Edit: I've awarded the question to the most comprehensive answer regarding the implementation with a vector data property. Appreciate all the responses!

  Read the article

• Design Technique: How to design a complex system for processing orders, products and units.

  - by Shyam

  Hi, Programming is fun: I learned that by trying out simple challenges, reading up some books and following some tutorials. I am able to grasp the concepts of writing with OO (I do so in Ruby), and write a bit of code myself. What bugs me though is that I feel re-inventing the wheel: I haven't followed an education or found a book (a free one that is) that explains me the why's instead of the how's, and I've learned from the A-team that it is the plan that makes it come together. So, armed with my nuby Ruby skills, I decided I wanted to program a virtual store. I figured out the following: My virtual Store will have: Products and Services Inventories Orders and Shipping Customers Now this isn't complex at all. With the help of some cool tools (CMapTools), I drew out some concepts, but quickly enough (thanks to my inferior experience in designing), my design started to bite me. My very first product-line were virtual "laptops". So, I created a class (Ruby): class Product attr_accessor :name, :price def initialize(name, price) @name = name @price = price end end which can be instantiated by doing (IRb) x = Product.new("Banana Pro", 250) Since I want my virtual customers to be able to purchase more than one product, or various types, I figured out I needed some kind of "Order" mechanism. class Order def initialize(order_no) @order_no = order_no @line_items = [] end def add_product(myproduct) @line_items << myproduct end def show_order() puts @order_no @line_items.each do |x| puts x.name.to_s + "\t" + x.price.to_s end end end that can be instantiated by doing (IRb) z = Order.new(1234) z.add_product(x) z.show_order Splendid, I have now a very simple ordering system that allows me to add products to an order. But, here comes my real question. What if I have three models of my product (economy, business, showoff)? Or have my products be composed out of separate units (bigger screen, nicer keyboard, different OS)? Surely I could make them three separate products, or add complexity to my product class, but I am looking for are best practices to design a flexible product object that can be used in the real world, to facilitate a complex system. My apologies if my grammar and my spelling are with error, as english is not my first language and I took the time to check as far I could understand and translate properly! Thank you for your answers, comments and feedback!

  Read the article

< Previous Page | 236 237 238 239 240 241 242 243 244 245 246 247  | Next Page >