Search Results

Search found 22104 results on 885 pages for 'programming language'.

Page 521/885 | < Previous Page | 517 518 519 520 521 522 523 524 525 526 527 528  | Next Page >

  • What is the best way to format a date in JSON for Mongo DB storage

    - by Poul
    I have a date with a time. I'm using ruby, but the language shouldn't matter. d = "2010-04-01 13:00:00" What is the best way to format this date for Mongo DB? By 'best' I mean, is there a certain format I could use where Mongo would recognize it as a date and might give me more-advanced filtering optons? ie: If formatted correctly, could I ask Mongo to return all records whose month is '04'? Thanks!

    Read the article

  • Will these optimizations to my Ruby implementation of diff improve performance in a Rails app?

    - by grg-n-sox
    <tl;dr> In source version control diff patch generation, would it be worth it to use the optimizations listed at the very bottom of this writing (see <optimizations>) in my Ruby implementation of diff for making diff patches? </tl;dr> <introduction> I am programming something I have never done before and there might already be tools out there to do the exact thing I am programming but at this point I am having too much fun to care so I am still going to do it from scratch, even if there is a tool for this. So anyways, I am working on a Ruby on Rails app and need a certain feature. Basically I want each entry in a table of mine, let's say for example a table of video games, to have a stored chunk of text that represents a review or something of the sort for that table entry. However, I want this text to be both editable by any registered user and also keep track of different submissions in a version control system. The simplest solution I could think of is just implement a solution that keeps track of the text body and the diff patch history of different versions of the text body as objects in Ruby and then serialize it, preferably in human readable form (so I'll most likely use YAML for this) for editing if needed due to corruption by a software bug or a mistake is made by an admin doing some version editing. So at first I just tried to dive in head first into this feature to find that the problem of generating a diff patch is more difficult that I thought to do efficiently. So I did some research and came across some ideas. Some I have implemented already and some I have not. However, it all pretty much revolves around the longest common subsequence problem, as you would already know if you have already done anything with diff or diff-like features, and optimization the function that solves it. Currently I have it so it truncates the compared versions of the text body from the beginning and end until non-matching lines are found. Then it solves the problem using a comparison matrix, but instead of incrementing the value stored in a cell when it finds a matching line like in most longest common subsequence algorithms I have seen examples of, I increment when I have a non-matching line so as to calculate edit distance instead of longest common subsequence. Although as far as I can tell between the two approaches, they are essentially two sides of the same coin so either could be used to derive an answer. It then back-traces through the comparison matrix and notes when there was an incrementation and in which adjacent cell (West, Northwest, or North) to determine that line's diff entry and assumes all other lines to be unchanged. Normally I would leave it at that, but since this is going into a Rails environment and not just some stand-alone Ruby script, I started getting worried about needing to optimize at least enough so if a spammer that somehow knew how I implemented the version control system and knew my worst case scenario entry still wouldn't be able to hit the server that bad. After some searching and reading of research papers and articles through the internet, I've come across several that seem decent but all seem to have pros and cons and I am having a hard time deciding how well in this situation that the pros and cons balance out. So are the ones listed here worth it? I have listed them with known pros and cons. </introduction> <optimizations> Chop the compared sequences into multiple chucks of subsequences by splitting where lines are unchanged, and then truncating each section of unchanged lines at the beginning and end of each section. Then solve the edit distance of each subsequence. Pro: Changes the time increase as the changed area gets bigger from a quadratic increase to something more similar to a linear increase. Con: Figuring out where to split already seems like you have to solve edit distance except now you don't care how it is changed. Would be fine if this was solvable by a process closer to solving hamming distance but a single insertion would throw this off. Use a cryptographic hash function to both convert all sequence elements into integers and ensure uniqueness. Then solve the edit distance comparing the hash integers instead of the sequence elements themselves. Pro: The operation of comparing two integers is faster than the operation of comparing two strings, so a slight performance gain is received after every comparison, which can be a lot overall. Con: Using a cryptographic hash function takes time to convert all the sequence elements and may end up costing more time to do the conversion that you gain back from the integer comparisons. You could use the built in hash function for a string but that will not guarantee uniqueness. Use lazy evaluation to only calculate the three center-most diagonals of the comparison matrix and then only calculate additional diagonals as needed. And then also use this approach to possibly remove the need on some comparisons to compare all three adjacent cells as desribed here. Pro: Can turn an algorithm that always takes O(n * m) time and make it so only worst case scenario is that time, best case becomes practically linear, and average case is somewhere between the two. Con: It is an algorithm I've only seen implemented in functional programming languages and I am having a difficult time comprehending how to convert this into Ruby based on how it is described at the site linked to above. Make a C module and do the hard work at the native level in C and just make a Ruby wrapper for it so Ruby can make all the calls to it that it needs. Pro: I have to imagine that evaluating something like this in could be a LOT faster. Con: I have no idea how Rails handles apps with ruby code that has C extensions and it hurts the portability of the app. This is an optimization for after the solving of edit distance, but idea is to store additional combined diffs with the ones produced by each version to make a delta-tree data structure with the most recently made diff as the root node of the tree so getting to any version takes worst case time of O(log n) instead of O(n). Pro: Would make going back to an old version a lot faster. Con: It would mean every new commit, the delta-tree would get a new root node that will cost time to reorganize the delta-tree for an operation that will be carried out a lot more often than going back a version, not to mention the unlikelihood it will be an old version. </optimizations> So are these things worth the effort?

    Read the article

  • Listing like appstore in firefox

    - by jenso
    A little question about the listing in iphone os and some other applications, and possibly in android market. When listing the apps, it fills the list in an automatic process, when reaching or is near to reach the end. My question is: How is that written in iphone applications. But the main question is: Is that possible to make for firefox users with javascript, ajax or possibly any other language? out

    Read the article

  • If it is possible to auto-format code before and after a source control commit, checkout, diff, etc.

    - by dennisjtaylor
    If it is possible to auto-format code before and after a source control commit, checkout, diff, etc. does a company really need a standard code style? It feels like standard coding style debates that have been raging since programming began like "put the bracket on the following line" or "properly indent your (" are no longer essential. I realize in languages where white space matters the diff will have to consider it but for languages where the style is a personal preference is there really a need to worry about it anymore?

    Read the article

  • Can' get couchdb external http handlers to work.

    - by fuzzy lollipop
    following the instructions here http://wiki.apache.org/couchdb/ExternalProcesses this is what I get { * error: "{{badarg,[{erlang,port_command, [#Port<0.2056>, [123, [34,<<"info">>,34], 58, [123, [34,"db_name",34], 58, [34,<<"transfer_central">>,34], 44, [34,"doc_count",34], 58,"39441",44, [34,"doc_del_count",34], 58,"0",44, [34,"update_seq",34], 58,"56508",44, [34,"purge_seq",34], 58,"0",44, [34,"compact_running",34], 58,<<"false">>,44, [34,"disk_size",34], 58,"43593828",44, [34,"instance_start_time",34], 58, [34,<<"1272560477320483">>,34], 44, [34,"disk_format_version",34], 58,"5",125], 44, [34,<<"id">>,34], 58,<<"null">>,44, [34,<<"method">>,34], 58, [34,"GET",34], 44, [34,<<"path">>,34], 58, [91, [34,<<"transfer_central">>,34], 44, [34,<<"_test">>,34], 93], 44, [34,<<"query">>,34], 58,<<"{}">>,44, [34,<<"headers">>,34], 58, [123, [34,<<"Accept">>,34], 58, [34, <<"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8,application/json">>, 34], 44, [34,<<"Accept-Charset">>,34], 58, [34,<<"ISO-8859-1,utf-8;q=0.7,*;q=0.7">>,34], 44, [34,<<"Accept-Encoding">>,34], 58, [34,<<"gzip,deflate">>,34], 44, [34,<<"Accept-Language">>,34], 58, [34,<<"en-us,en;q=0.5">>,34], 44, [34,<<"Connection">>,34], 58, [34,<<"keep-alive">>,34], 44, [34,<<"Host">>,34], 58, [34,<<"127.0.0.1:5984">>,34], 44, [34,<<"Keep-Alive">>,34], 58, [34,<<"115">>,34], 44, [34,<<"User-Agent">>,34], 58, [34, <<"Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3">>, 34], 125], 44, [34,<<"body">>,34], 58, [34,"undefined",34], 44, [34,<<"peer">>,34], 58, [34,<<"127.0.0.1">>,34], 44, [34,<<"form">>,34], 58,<<"{}">>,44, [34,<<"cookie">>,34], 58,<<"{}">>,44, [34,<<"userCtx">>,34], 58, [123, [34,<<"db">>,34], 58, [34,<<"transfer_central">>,34], 44, [34,<<"name">>,34], 58,<<"null">>,44, [34,<<"roles">>,34], 58,<<"[]">>,125], 125,10]]}, {couch_os_process,writeline,2}, {couch_os_process,writejson,2}, {couch_os_process,handle_call,3}, {gen_server,handle_msg,5}, {proc_lib,init_p_do_apply,3}]}, {gen_server,call, [<0.110.0>, {prompt,{[{<<"info">>, {[{db_name,<<"transfer_central">>}, {doc_count,39441}, {doc_del_count,0}, {update_seq,56508}, {purge_seq,0}, {compact_running,false}, {disk_size,43593828}, {instance_start_time,<<"1272560477320483">>}, {disk_format_version,5}]}}, {<<"id">>,null}, {<<"method">>,'GET'}, {<<"path">>,[<<"transfer_central">>,<<"_test">>]}, {<<"query">>,{[]}}, {<<"headers">>, {[{<<"Accept">>, <<"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8,application/json">>}, {<<"Accept-Charset">>, <<"ISO-8859-1,utf-8;q=0.7,*;q=0.7">>}, {<<"Accept-Encoding">>,<<"gzip,deflate">>}, {<<"Accept-Language">>,<<"en-us,en;q=0.5">>}, {<<"Connection">>,<<"keep-alive">>}, {<<"Host">>,<<"127.0.0.1:5984">>}, {<<"Keep-Alive">>,<<"115">>}, {<<"User-Agent">>, <<"Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3">>}]}}, {<<"body">>,undefined}, {<<"peer">>,<<"127.0.0.1">>}, {<<"form">>,{[]}}, {<<"cookie">>,{[]}}, {<<"userCtx">>, {[{<<"db">>,<<"transfer_central">>}, {<<"name">>,null}, {<<"roles">>,[]}]}}]}}, infinity]}}" * reason: "{gen_server,call, [<0.109.0>, {execute,{[{<<"info">>, {[{db_name,<<"transfer_central">>}, {doc_count,39441}, {doc_del_count,0}, {update_seq,56508}, {purge_seq,0}, {compact_running,false}, {disk_size,43593828}, {instance_start_time,<<"1272560477320483">>}, {disk_format_version,5}]}}, {<<"id">>,null}, {<<"method">>,'GET'}, {<<"path">>,[<<"transfer_central">>,<<"_test">>]}, {<<"query">>,{[]}}, {<<"headers">>, {[{<<"Accept">>, <<"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8,application/json">>}, {<<"Accept-Charset">>, <<"ISO-8859-1,utf-8;q=0.7,*;q=0.7">>}, {<<"Accept-Encoding">>,<<"gzip,deflate">>}, {<<"Accept-Language">>,<<"en-us,en;q=0.5">>}, {<<"Connection">>,<<"keep-alive">>}, {<<"Host">>,<<"127.0.0.1:5984">>}, {<<"Keep-Alive">>,<<"115">>}, {<<"User-Agent">>, <<"Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3">>}]}}, {<<"body">>,undefined}, {<<"peer">>,<<"127.0.0.1">>}, {<<"form">>,{[]}}, {<<"cookie">>,{[]}}, {<<"userCtx">>, {[{<<"db">>,<<"transfer_central">>}, {<<"name">>,null}, {<<"roles">>,[]}]}}]}}, infinity]}" }

    Read the article

  • why develop in windows/desktop application?

    - by Alexander
    Just wondering what your comments are regarding the current trend as everything is moving to the web or even the cloud. The significance of an OS or desktop application is getting less attention than web application. So to those folks out there who still develop windows applications, such as WPF. Why still do it? Why not move to web programming? Silverlight instead for example...

    Read the article

  • server|configuration problem, a php script just die with no error log & no reason

    - by Roberto
    Hi (first of all, thanks for your attention & sorry for my bad english hahaha also this is not a programming error, or thats what I think, I think this is an error in some configuration of the server or something else but I dont know what) I have a php script (is running like a process of linux, its not running on the web browser) that send SMS via SMPP on the port 2055 (using sockets in php) & then inserts like 10,000 rows into a dababase on MySQL, the script gets the data from a XML file; firts it was running in a shared server (Hostgator is our hosting provider) & at the begining it worked fine, with no trouble, but 5 months later an error appear, the process just die with no reason, the script only sent & inserted 700 rows in the table of the database & the process didnt show any warning or error, nothing appears in the error logs, & I didnt make any change in the script Hostgator never helped us hahaha so we decided to move the script from the shared server to a dedicated server; I thought it was a memory problem or something like that, but when we move the script to the dedicated server the problem just get worse, the script die when has just sent & inserted 40 to 50 rows to the database the information about this error: the shared server is on Red Hat 4.1.2-46 & the dedicated server is on CentOS 5.4 I have commented the line that sends the SMS, & the problem remains in the shared server, at the begining the script was fine, but then the script started to die when has just inserted 700 aprox. in the database, & now the script is dying when has inserted 2500 rows, its better but we didnt change anything in the dedicated server, the script dies when has just inserted like 40 row in the table the script, before it dies, change to a zombie process & we dont know why the usage of memory appears to be 0.3%, and of the cpu appears to be 0.7% to 1% I have changed the max memory limit of php to 128Mb, and even to -1 (so php wont have any limit) but the problem remains we have the limit of 50 connections of mysql at the same time, so I think this is not the problem Im using mysqli to connect from php to mysql Hostgator report that they haven't made any change or update in the servers what could be the problem?? what should I do??? what should I search??? is something in the logic Im missing?? what steps do I have to follow when managing & searching problems of process on Linux??? thank you very much, I think this is not a programming problem, but you have more experience than me, you can tell me thanks!!! bye!!! :)

    Read the article

  • What is the best service/tool to put short audio clips on a website so users can click and listen im

    - by Edward Tanguay
    I'm making a foreign language flashcard website in which I want to have 100s of short 3-10 second audio files available for users to click and listen. So I am looking for a tool/service such as YouTube or Screenr.com but for audio which e.g.: allows me to easily upload multiple kinds of audio files: mp3, wav, etc. easy to manage them online (delete, replace) has a simple, small player (e.g. flash) that integrates nicely into any site

    Read the article

  • is Checkland's approach still relevant today?

    - by WeNeedAnswers
    I remember back in the mid 90's that I came across a systems methodology called Checkland's Approach or sometimes called SSM (Soft Systems Methodology). With the advent of Agile and Extreme Programming, not to mention some of the harder methodologies and methods out there related to Object technologies. Is the use of such a methodology still relevant in today's world?

    Read the article

  • Which python mpi library to use?

    - by Dana the Sane
    I'm starting work on some simulations using MPI and want to do the programming in Python/scipy. The scipy site lists a number of mpi libraries, but I was hoping to get feedback on quality, ease of use, etc from anyone who has used one.

    Read the article

  • Why can't I inherit static classes?

    - by User
    I have several classes that do not really need any state. From the organizational point of view, I would like to put them into hierarchy. But it seems I can't declare inheritance for static classes. Something like that: public static class Base { } public static class Inherited : Base { } will not work. Why have the designers of the language closed that possibility?

    Read the article

  • Automatic bookkeeping for exception retries

    - by pilcrow
    Do any languages that support retry constructs in exception handling track and expose the number of times their catch/rescue (and/or try/begin) blocks have been executed in a particular run? I find myself counting (and limiting) the number of times a code block is re-executed after an exception often enough that this would be a handy language built-in.

    Read the article

  • Visual Studio support for coding in MSIL?

    - by jdk
    For the longest time I've been curious to code in Microsoft Intermediate Language (MSIL) just as an academic endeavour and to gain a better understanding of what's "happening under the hood". Is there any sort of Visual Studio support for this in the form of: project templates, IntelliSense integration, and those kind of RAD features?

    Read the article

  • How to get a good price on dev books

    - by mgroves
    Does anyone have any tips for getting a good price on new/used programming-related books? I've looked at some of the more popular books (like DDD and GoF), and even used they can be pretty pricey. I'm not saying they aren't worth it, but I feel like there might be a more focused book store or exchange or something just for devs and/or IT professionals that I just don't know about. Any tips at all would be appreciated.

    Read the article

  • Alternatives to fread and fwrite for use with structured data

    - by forest58
    The book Beginning Linux Programming (3rd ed) says "Note that fread and fwrite are not recommended for use with structured data. Part of the problem is that files written with fwrite are potentially nonportable between different machines." What does that mean exactly? What calls should I use if I want to write a portable structured data reader or writer? Direct system calls?

    Read the article

  • How to generate Function caller graphs for JavaScript and ActionScript?

    - by Jeremy Rudd
    I like the way Doxygen combines with Graphviz dot to generate function caller graphs. I'd like this functionality for other languages as well, apart from the basics that Doxygen supports (C++, C, Java, Objective-C, Python, VHDL, PHP, C#). I'm currently looking for tools that support JavaScript, ActionScript 2 and ActionScript 3/Flex. I'm also interested in tools that have a wider language support than Doxygen. Is there any way to get function caller graphs for any other languages?

    Read the article

  • BS in CS. Are specializations worth it?

    - by CheesePls
    I'm currently pursuing my BS in Computer Science and my school offers specializations based upon taking certain advanced electives. I was thinking about getting two of them since they are sort of on the way to my degree anyway. They are Software Engineering and Programming Languages and Compilers . Would these specializations actually be useful in finding a job? Would employers even care about them?

    Read the article

< Previous Page | 517 518 519 520 521 522 523 524 525 526 527 528  | Next Page >