Search Results

Search found 13883 results on 556 pages for 'language theory'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 112/556 | < Previous Page | 108 109 110 111 112 113 114 115 116 117 118 119  | Next Page >

  • Handling close-to-impossible collisions on should-be-unique values

    - by balpha
    There are many systems that depend on the uniqueness of some particular value. Anything that uses GUIDs comes to mind (eg. the Windows registry or other databases), but also things that create a hash from an object to identify it and thus need this hash to be unique. A hash table usually doesn't mind if two objects have the same hash because the hashing is just used to break down the objects into categories, so that on lookup, not all objects in the table, but only those objects in the same category (bucket) have to be compared for identity to the searched object. Other implementations however (seem to) depend on the uniqueness. My example (that's what lead me to asking this) is Mercurial's revision IDs. An entry on the Mercurial mailing list correctly states The odds of the changeset hash colliding by accident in your first billion commits is basically zero. But we will notice if it happens. And you'll get to be famous as the guy who broke SHA1 by accident. But even the tiniest probability doesn't mean impossible. Now, I don't want an explanation of why it's totally okay to rely on the uniqueness (this has been discussed here for example). This is very clear to me. Rather, I'd like to know (maybe by means of examples from your own work): Are there any best practices as to covering these improbable cases anyway? Should they be ignored, because it's more likely that particularly strong solar winds lead to faulty hard disk reads? Should they at least be tested for, if only to fail with a "I give up, you have done the impossible" message to the user? Or should even these cases get handled gracefully? For me, especially the following are interesting, although they are somewhat touchy-feely: If you don't handle these cases, what do you do against gut feelings that don't listen to probabilities? If you do handle them, how do you justify this work (to yourself and others), considering there are more probable cases you don't handle, like a supernonva?

    Read the article

  • Bit Flipping in Hex

    - by freyrs
    I have an 8 digit hexadecimal number of which I need certain digits to be either 0 or f. Given the specific place of the digits is there a quick way to generate the hex number with those places "flipped" to f. For example: flip_digits(1) = 0x000000f flip_digits(1,2,4) = 0x0000f0ff flip_digits(1,7,8) = 0xff00000f I'm doing this on an embedded device so I can't call any math libraries, I suspect it can be done with just bit shifts but I can't quite figure out the method. Any sort of solution (Python, C, Pseudocode) will work. Thanks in advance.

    Read the article

  • Matching an IP address with an IP range?

    - by Legend
    I have a MySQL table setup as follows: +---------------+-------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------------+-------------+------+-----+---------+----------------+ | ipaddress_s | varchar(15) | YES | MUL | NULL | | | ipaddress_e | varchar(16) | YES | | NULL | | +---------------+-------------+------+-----+---------+----------------+ where, ipaddress_s and ipaddress_e look something like: 4.100.159.0-4.100.159.255 Now is there a way I can actually get the row that contains a given IP address? For instance, given the IP address: "4.100.159.5", I want the above row to be returned. So I am trying for a query that looks something like this (but of course this is wrong because in the following I am considering IPs as strings): SELECT * FROM ranges WHERE ipaddress_s<"4.100.159.5" AND ipaddress_e>"4.100.159.5" Any suggestions?

    Read the article

  • Determining when or when not to escape output

    - by Ygam
    I have a page, where I have approximately 90 items I need to output. Most of them are object properties (I am using ORM so these objects map to my database tables). But the question is, do I have to escape each of those 90 outputs by applying functions to each (in my case, the htmlspecialchars)? Wouldn't that add a bit of an overhead (calling a single function 90 times)?

    Read the article

  • True random number generator

    - by goldenmean
    Sorry for this not being a "real" question, but Sometime back i remember seeing a post here about randomizing a randomizer randomly to generate truly random numbers, not just pseudo random. I dont see it if i search for it. Does anybody know about that article?

    Read the article

  • When does it make sense to use a map?

    - by kiwicptn
    I am trying to round up cases when it makes sense to use a map (set of key-value entries). So far I have two categories (see below). Assuming more exist, what are they? Please limit each answer to one unique category and put up an example. Property values (like a bean) age -> 30 sex -> male loc -> calgary Presence, with O(1) performance peter -> 1 john -> 1 paul -> 1

    Read the article

  • Are there still completely new programming languages and -paradigms to be born?

    - by llasa
    Are there still completely new programming languages and -paradigms (which will actually go mainstream and still be used decades after their appearance) to be born? What I'm talking about are groundbreaking things like the rise of object oriented programming, C++, or PHP. With new programming languages I mean that they actually are completely different from what you know, as different as when you set a guy who used assembler for a decade, and even programmed some kind of 3D game in it, in front of something as high-level as PHP, Ruby or Python? Which new paradigms and programming languages are there to come? What could be different about them? Who will possibly create them and how fast will they rise?

    Read the article

  • How to write efficient code for extracting Noun phrases?

    - by Arun Abraham
    I am trying to extract phrases using rules such as the ones mentioned below on text which has been POS tagged 1) NNP - NNP (- indicates followed by) 2) NNP - CC - NNP 3) VP - NP etc.. I have written code in this manner, Can someone tell me how i can do in a better manner. List<String> nounPhrases = new ArrayList<String>(); for (List<HasWord> sentence : documentPreprocessor) { //System.out.println(sentence.toString()); System.out.println(Sentence.listToString(sentence, false)); List<TaggedWord> tSentence = tagger.tagSentence(sentence); String lastTag = null, lastWord = null; for (TaggedWord taggedWord : tSentence) { if (lastTag != null && taggedWord.tag().equalsIgnoreCase("NNP") && lastTag.equalsIgnoreCase("NNP")) { nounPhrases.add(taggedWord.word() + " " + lastWord); //System.out.println(taggedWord.word() + " " + lastWord); } lastTag = taggedWord.tag(); lastWord = taggedWord.word(); } } In the above code, i have done only for NNP followed by NNP extraction, how can i generalise it so that i can add other rules too. I know that there are libraries available for doing this , but wanted to do this manually.

    Read the article

  • Is there anyone out there that codes like me?

    - by Jacob Relkin
    Hi, Some people have told me that my coding style is a lot different than theirs. I think I am somewhat neurotic when it comes to spacing and indenting though. Here's a snippet to show you what I mean: - ( void ) applicationDidFinishLaunching: ( UIApplication *) application { SomeObject *object = [ [ SomeObject alloc ] init ]; int x = 100 / 5; object.someInstanceVariable = ( ( 4 * x ) + rand() ); [ object someMethod ]; } Notice how I space out all of my brackets/parentheses, start curly braces on the same line, "my code has room to breathe", so to speak. So my questions are a) is this normal and b) What's your coding style?

    Read the article

  • Are there equivalents to Ruby's method_missing in other languages?

    - by Justin Ethier
    In Ruby, objects have a handy method called method_missing which allows one to handle method calls for methods that have not even been (explicitly) defined: Invoked by Ruby when obj is sent a message it cannot handle. symbol is the symbol for the method called, and args are any arguments that were passed to it. By default, the interpreter raises an error when this method is called. However, it is possible to override the method to provide more dynamic behavior. The example below creates a class Roman, which responds to methods with names consisting of roman numerals, returning the corresponding integer values. class Roman def romanToInt(str) # ... end def method_missing(methId) str = methId.id2name romanToInt(str) end end r = Roman.new r.iv #=> 4 r.xxiii #=> 23 r.mm #=> 2000 For example, Ruby on Rails uses this to allow calls to methods such as find_by_my_column_name. My question is, what other languages support an equivalent to method_missing, and how do you implement the equivalent in your code?

    Read the article

  • What are some good code optimization methods?

    - by esac
    I would like to understand good code optimization methods and methodology. How do I keep from doing premature optimization if I am thinking about performance already. How do I find the bottlenecks in my code? How do I make sure that over time my program does not become any slower? What are some common performance errors to avoid (e.g.; I know it is bad in some languages to return while inside the catch portion of a try{} catch{} block

    Read the article

  • Convince teammates to follow standards

    - by folone
    There's always one or two guys, who think, they are great programmers, and they don't need any literature/specifications/etc. They usually write awful code, that makes you want to hurt them. They catch and suppress Throwable's, return null's, concatenate String's in large loops, do other stupid stuff. So the question is — How do I make such a person follow best practices and specifications? He does not listen (cause he's the best programmer), team lead does not give a damn ("It actually works, so why changing it?.."), and I'm actually tired of rewriting that awful code on my own. What do I do? What would you do?

    Read the article

  • routine to generate a 2d array from two 1d arrays and a function

    - by intuited
    I'm guessing that there's a word for this concept, and that it's available in at least some popular languages, but my perfunctory search was fruitless. A pseudocode example of what I'd like to do: function foo(a, b) { return a * b // EG } a = [ 1, 2, 3 ] b = [ 4, 5, 6 ] matrix = the_function_for_which_I_search(foo, [a, b] ) print matrix => [ [ 4, 8, 12], [5, 10, 15], [6, 12, 18] ] // or function concatenate(a,b) return a.b } print the_function_for_which_I_search( concatenate, [ a, b ]) => [ [ '14', '24', '34'], ['15', '25', '35'], [16', '26', '36'] ] In other words, function_for_which_I_search will apply the function given as its first argument to each combination of the elements of the two arrays passed as its second argument, and return the results as a two-dimensional array. I would like to know if such a routine has a common name, and if it's available in a python module, cpan package, ruby gem, pear package, etc. I'm also wondering if this is a core function in other languages, maybe haskell or R?

    Read the article

  • What is an efficient way to find a non-colliding rectangle nearest to a location

    - by hyn
    For a 2D game I am working on, I am using y axis sorting in a simple rectangle-based collision detection. This is working fine, and now I want to find the nearest empty rectangle at a given location with a given size, efficiently. How can I do this? Is there an algorithm? I could think of a simple brute force grid test (with each grid the size of the empty space we're looking for) but obviously this is slow and not even a complete test.

    Read the article

  • How to handle printing of HTML pages?

    - by Jaran
    In my portfolio site I have listed my projects under separate tabs (tab menu). This works well except for printing which requires the user to click on a tab, print, click on the next tab and print the same page again to get everything. Being a portfolio I'd assume that visitors want to print all of the content. Is there a general way to create a different style when printing a web page? Or should I just add a printer icon on my page which redirects the user to a different page where all the data is in a big chunk and then prompt the user's browser to start printing?

    Read the article

  • How to design a command line program reusable for a future development of a GUI?

    - by systempuntoout
    What are some best practices to keep in mind when developing a script program that could be integrated with a GUI, probably by somebody else, in the future? Possible scenario: i develop a fancy python CLI program that scrapes every unicorn images from the web i decide to publish it on github a unicorn fan programmer decides to take the sources and build a GUI on them. he\she gives up because my code is not reusable How do i avoid step four and let unicorn fan programmer build his\her GUI without hassle?

    Read the article

  • How to program simple chat bot AI?

    - by Larsenal
    I want to build a bot that asks someone a few simple questions and branches based on the answer. I realize parsing meaning from the human responses will be challenging, but how do you setup the program to deal with the "state" of the conversation? EDIT: It will be a one-to-one conversation between a human and the bot.

    Read the article

  • What Use are Threads Outside of Parallel Problems on MultiCore Systesm?

    - by Robert S. Barnes
    Threads make the design, implementation and debugging of a program significantly more difficult. Yet many people seem to think that every task in a program that can be threaded should be threaded, even on a single core system. I can understand threading something like an MPEG2 decoder that's going to run on a multicore cpu ( which I've done ), but what can justify the significant development costs threading entails when you're talking about a single core system or even a multicore system if your task doesn't gain significant performance from a parallel implementation? Or more succinctly, what kinds of non-performance related problems justify threading? Edit Well I just ran across one instance that's not CPU limited but threads make a big difference: TCP, HTTP and the Multi-Threading Sweet Spot Multiple threads are pretty useful when trying to max out your bandwidth to another peer over a high latency network connection. Non-blocking I/O would use significantly less local CPU resources, but would be much more difficult to design and implement.

    Read the article

  • WPF custom user widgets. Will UI components be standardized?

    - by Andrew Florko
    There are lots of articles and video lessons that describe how to create your unique user widget (graphical control) with WPF. There are tons of technical details what is behind the scene and I feel people enthusiasm with ability to customize widgets as never before. I remember those days when VCL library (Delphi) appeared and there was the same enthusiasm in VCL widgets area. Ability to create VCL controls was nearly the must when you was applying for a job as Delphi developer. This situation continued for several years till professional sophisticated 3'd party UI libraries appeared. Hardly you'll have to create your own VCL widget nowadays. Will WPF widgets enthusiasm die as VCL one?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 108 109 110 111 112 113 114 115 116 117 118 119  | Next Page >