Search Results

Search found 14292 results on 572 pages for 'high integrity systems'.

Page 393/572 | < Previous Page | 389 390 391 392 393 394 395 396 397 398 399 400  | Next Page >

  • How to write a shell in Python

    - by panzi
    I've written a small console application that can perform certain tasks. The user interface is similar to things like version control systems or yum etc. So basically you can think of it as a domain specific language. Now I'd like to write a (bash like) shell that can execute and auto-complete this language and has a command history (so I do not have to load and save the quite large xml files on each command). In a nutshell I want something like ipython but not for executing python code but my own DSL. Are there any libraries that help me doing this? I see that there is a readline and rlcompleter module in python but its documentation seems to indicate that this is only for use with the python shell itself, or did I miss something there?

    Read the article

  • In Elixir or SQLAlchemy, is there a way to also store a comment for a/each field in my entities?

    - by kchau
    Our project is basically a web interface to several systems of record. We have many tables mapped, and the names of each column aren't as well named and intuitive as we'd like... The users would like to know what data fields are available (i.e. what's been mapped from the database). But, it's pointless to just give them column names like: USER_REF1, USER_REF2, etc. So, I was wondering, is there a way to provide a comment in the declaration of my field? E.g. class SegregationCode(Entity): using_options(tablename="SEGREGATION_CODES") segCode = Field(String(20), colname="CODE", ... primary_key=True) #Have a comment attr too? If not, any suggestions?

    Read the article

  • capistrano put() and upload() both failing

    - by Kyle
    With capistrano, I am deploying a Rails application from Mac OS X 10.5 to CentOS 5.2 Note that deploy.rb and the server environment have not changed in over a year. There is a task within our deploy.rb file called upload: put(File.read( file ),"#{shared_path}/#{filename}", :via => :scp) This fails each and every time with the following exception: No such file or directory - /srv/ourapp/releases/20100104194410/config/database.yml My local copy of config/database.yml is failing to upload properly. I've verified it's not our internet connection, as this happens on three different connections and two different systems. I've also tried to swap out put() for upload() but get the same result; also, dropping :via = :scp, and/or trying to force :sftp instead similarly fails. Relevant info: $ cap -V Capistrano v2.5.10 $ ruby -v ruby 1.8.7 (2008-08-11 patchlevel 72) [i686-darwin9.6.0]

    Read the article

  • iPhone App Development - UITableView DetailsView

    - by leo
    Hi, I have a UITableView with a list of items such as item1, item2, item3, item4 and so on. If I select on item1, it will go to the detail view of item1 (which is controlled by DetailsViewController). What I am trying to do is to add a button called "Next" on DetailsView. When clicked, the DetailsView will refresh and show item2. When clicked again, it will show item3 and so on. I have been searching high and low for that to implement. But to no avail. Many thanks in advance!!!

    Read the article

  • Recommendations for an in memory database vs thread safe data structures

    - by yx
    TLDR: What are the pros/cons of using an in-memory database vs locks and concurrent data structures? I am currently working on an application that has many (possibly remote) displays that collect live data from multiple data sources and renders them on screen in real time. One of the other developers have suggested the use of an in memory database instead of doing it the standard way our other systems behaves, which is to use concurrent hashmaps, queues, arrays, and other objects to store the graphical objects and handling them safely with locks if necessary. His argument is that the DB will lessen the need to worry about concurrency since it will handle read/write locks automatically, and also the DB will offer an easier way to structure the data into as many tables as we need instead of having create hashmaps of hashmaps of lists, etc and keeping track of it all. I do not have much DB experience myself so I am asking fellow SO users what experiences they have had and what are the pros & cons of inserting the DB into the system?

    Read the article

  • Specification: Use cases for CRUD

    - by Mario Ortegón
    I am writing a Product requirements specification. In this document I must describe the ways that the user can interact with the system in a very high level. Several of these operations are "Create-Read-Update-Delete" on some objects. The question is, when writing use cases for these operations, what is the right way to do so? Can I write only one Use Case called "Manage Object x" and then have these operations as included Use Cases? Or do I have to create one use case per operation, per object? The problem I see with the last approach is that I would be writing quite a few pages that I feel do not really contribute to the understanding of the problem. What is the best practice?

    Read the article

  • how to translate Haskell into Scalaz?

    - by TOB
    One of my high school students and I are going to try to do a port of Haskell's Parsec parser combinator library into Scala. (It has the advantage over Scala's built-in parsing library that you can pass state around fairly easily because all the parsers are monads.) The first hitch I've come across is trying to figure out how Functor works in scalaz. Can someone explain how to convert this Haskell code: data Reply s u a = Ok a !(State s u) ParseError | Error ParseError instance Functor (Reply s u) where fmap f (Ok x s e) = Ok (f x) s e fmap _ (Error e) = Error e -- XXX into Scala (using Scalaz, I assume). I got as far as sealed abstract class Reply[S, U, A] case class Ok[S, U, A](a: A, state: State[S, U], error: ParseError) extends Reply[S, U, A] case class Error[S, U, A](error: ParseError) extends Reply[S, U, A] and know that I should make Reply extend the scalaz.Functor trait, but I can't figure out how to do that. (Mostly I'm having trouble figuring out what the F[_] parameter does.) Any help appreciated! Thanks, Todd

    Read the article

  • mongodb read/write performance and mongo hosting in the cloud

    - by z3cko
    we are currently developing a high traffic rails application with facebooker (facebook game). since amazon simpledb (aws-sdb) is really slow, we are thinking of using a dedicated mongodb server as offered by mongoHQ for example. questions: what is the read/writes peak value for a mongodb server running on a amazon ec2 instance? what would be a recommended setup for a ec2 hosted app with mongodb - a master on amazon EBS and replicas on the ec2 instances? any examples or experiences? is there a company that offers mongodb hosting in the cloud? thanks, mz

    Read the article

  • Analysis and Design for Functional Programming

    - by edalorzo
    How do you deal with analysis and design phases when you plan to develop a system using a functional programming language like Haskell? My background is in imperative/object-oriented programming languages, and therefore, I am used to use case analysis and the use of UML to document the design of program. But the thing is that UML is inherently related to the object-oriented way of doing software. And I am intrigued about what would be the best way to develop documentation and define software designs for a system that is going to be developed using functional programming. Would you still use use case analysis or perhaps structured analysis and design instead? How do software architects define the high-level design of the system so that developers follow it? What do you show to you clients or to new developers when you are supposed to present a design of the solution? How do you document a picture of the whole thing without having first to write it all? Is there anything comparable to UML in the functional world?

    Read the article

  • What features of interpreted languages can a compiled one not have?

    - by sub
    Interpreted languages are usually more high-level and therefore have features as dynamic typing (including creating new variables dynamically without declaration), the infamous eval and many many other features that make a programmer's life easier - but why can't compiled languages have these as well? I don't mean languages like Java that run on a VM, but those that compile to binary like C(++). I'm not going to make a list now but if you are going to ask which features I mean, please look into what PHP, Python, Ruby etc. have to offer. Which common features of interpreted languages can't/don't/do exist in compiled languages? Why?

    Read the article

  • How to make a button button type (custom keyboard)

    - by Forrest
    I am creating a Spanish application in C# which will help first year students at my high school. I want to create a "custom keyboard" for characters that cannot be easily typed (Á É Í Ó Ú Ñ Ü ¡ ¿ á é í ó ú ñ ü). I was just thinking of making buttons across the bottom of the screen which would add that character to the text field when pressed. I have not be able to find anything of use. Thanks in advance

    Read the article

  • Accessing the DI container from anywhere

    - by ChrisR
    I've implemented the Symfony2 Dependency Injection container in my Zend Framework project and it works fine in the MVC layer of my application. I've initialized the DIC in my bootstrap and can access it anywhere by calling: Zend_Controller_Front::getInstance()->getParam('bootstrap')->getDic() The problem is that there are some parts of my application that do not utilize the Zend Framework application/MVC layer. My CLI tools for example. I could perfectly initialize a new DIC there but that would just be some copy paste work from the Bootstrap file which is asking for trouble down the road (DRY principles, etc) Is it a better solution to make my DIC available in the Zend_Registry or as a singleton called by a static method DIC::getInstance() for example? I know Registry and singletons are considered bad things but the DIC is such a high level part of the application that I will probably never run into the problems that make it a bad thing. Is this a good solution or are there better ways of accomplishing a globally accessible DIC?

    Read the article

  • How do I draw an ellipse with arbitrary orientation pixel by pixel?

    - by amc
    Hi, I have to draw an ellipse of arbitrary size and orientation pixel by pixel. It seems pretty easy to draw an ellipse whose major and minor axes align with the x and y axes, but rotating the ellipse by an arbitrary angle seems trickier. Initially I though it might work to draw the unrotated ellipse and apply a rotation matrix to each point, but it seems as though that could cause errors do to rounding, and I need rather high precision. Is my suspicion about this method correct? How could I accomplish this task more precisely? I'm programming in C++ (although that shouldn't really matter since this is a more algorithm-oriented question).

    Read the article

  • Can I use the newer versions of Visual Studio to do "old" things?

    - by Ptah- Opener of the Mouth
    I have several ATL/COM-based DLLs that I've been using Visual C++ 6.0 on. I require a couple of "old" things out of the generated DLLs: (1) They must be compatible with projects developed in Visual Basic 6.0 (the old VB6, emphatically not VB.Net). (2) They must be compatible with old operating systems - minimum Windows 98 SE. To be clear, I mean they must run on such OSes, not that I would have to be able to develop them on a machine running such an OS. I am sick of Visual Studio 6.0. Converting to Dot Net (or any other major change like that) is out of the question at the current time, so I must continue to use VB6. But can I switch to the newer Visual Studio's C++, with a minimum of effort (i.e. little if any required recoding)? If so, are there any "gotchas" I should watch out for? Thanks.

    Read the article

  • Do I assign different or the same class id to 32-bit and 64-bit versions of the same IFilter?

    - by sharptooth
    I've implemented my own Microsoft Search IFilter. I need two versions of it - 32-bit and 64-bit for deploying them on corresponding systems. In case of IFilters for any file extension I can only register one IFilter class id. Which means I can only use one version on any system. So having two class ids seems useless - it only makes the automatic installer more complex. Do I reuse the same COM class id for both or do I use different class ids?

    Read the article

  • PHP Segmentation fault when started from crond

    - by Jeroen Moors
    Hello, I've a php script that's started each minute from cron. It almost always runs without any problem, except for about 10 times within 24h. The times it fails I get a segmentation fault like: bin/sh: line 1: 21815 Segmentation fault /usr/bin/myscript The number after "line 1:" is always different. I'm running: PHP 5.2.6-1+lenny8 with Suhosin-Patch 0.9.6.2 (cli) (built: Mar 14 2010 08:14:04) Is this a problem with my version of PHP? Is there a way to debug this? I have the feeling it crashes when the server load is high, but there's absolutely no prove for this. Any feedback is welcome!

    Read the article

  • How to decouple an app's agile development from a database using BDUF?

    - by Rob Wells
    G'day, I was reading the article "Database as a Fortress" by Dan Chak from the excellent book "97 Things Every Software Architect Should Know" (sanitised Amazon link) which suggests that databases should not be designed using an agile approach. There's an SO question on agile approaches and databases "Agile development and database changes" which has some excellent answers covering agile development approaches. In fact, one of the answers supplies a brilliant idea of what's needed for each update of the DB. ;-) But after reading Dan Chak's article, I am left wondering if an agile approach is really suitable for large scale systems. This of course leads on to the question of how best to decouple an agile approach for the application that is interacting with the BDUF database design without adding complicated translation layers in the final design employed? Any suggestions? cheers,

    Read the article

  • Algorithm for Source Control System?

    - by Michael Stum
    I need to write a simple source control system and wonder what algorithm I would use for file differences? I don't want to look into existing source code due to license concerns. I need to have it licensed under MPL so I can't look at any of the existing systems like CVS or Mercurial as they are all GPL licensed. Just to give some background, I just need some really simple functions - binary files in a folder. no subfolders and every file behaves like it's own repository. No Metadata except for some permissions. Overall really simple stuff, my single concern really is how to store only the differences of a file from revision to revision without wasting too much space but also without being too inefficient (Maybe store a full version every X changes, a bit like Keyframes in Videos?)

    Read the article

  • Is Software Development a Part of IT

    - by kzh
    I am not sure if this question is in the scope of SO, but I will ask anyway... I am currently going to school, majoring in Computer Science. Often I overhear students in the Management of Information Systems major call themselves programmers. These comments make me angry for a few reasons: They seem to trivialize what I do. Most of them are not even capable of doing what I can do. To me, MIS is IT and the are technicians and software developers are engineers and are not IT. So I guess my question is, Is software development part of IT? I often see them lumped together.

    Read the article

  • How to prevent Artificial Intelligence from escaping into the internet?

    - by Jason
    I have an interest in artificial intelligence from a evolutionary standpoint. I want to experiment with it somewhat with a high level language like C#, however, I'm stuck on one of the most elementary problems with artificial life -- how to contain it? The best thing I can think of is a virtual machine. Where would I start to create a VM for my budding digital organisms in C#? How could I be sure they couldn't escape into the 'wild'? (I understand this unlikely, by the way.)

    Read the article

  • Career path decisions

    - by MindFold
    Hi all, I'm on a verge of quitting my current job as a .NET programmer. i'm 25 years old and have been a .NET programmer in the past 5-6 years, but now i wonder if maybe i should take this opurtunity and try some other things, like RT\Embedded or Driver development. My pro\cons: i love .NET since you can write enterprise systems with it, learn cool development methodologies and practice many patterns i want to learn RT\Embedded\Driver since its at the heart of so many things and i'm feeling this is a black hole for me. My question are: Is making career leaps a good idea? How can i manage to get myself into a job in RT\Embedded as my whole Resume has c# written all over it. What should i bet my cards on this days? android? java? flash? silverlight? etc?

    Read the article

  • HTML5: HTML VS XHTML spec question regarding comments

    - by NoozNooz42
    In the W3C working draft for HTML5 here's a line I find confusing: http://www.w3.org/TR/html5/introduction.html#html-vs-xhtml Comments that contain the string "--" can be represented in the DOM but not in the HTML syntax or in XML. I can interpret this in two different ways: Comments that contain the string "--" can be represented in XML and in the DOM but not in the HTML syntax Comments that contain the string"--" can be represented in the DOM but neither in the HTML syntax nor in XML. I really find the original formulation highly confusing. Which one does it mean and is it even correct english? Who should I contact if I want to point out that I find such a wording highly confusing and that hence there's a high probability that other non-native english speaker would find this kind of formulation highly confusing too?

    Read the article

  • NoSQL and meteorological data

    - by christian studer
    So there's this new cool thing, these NoSQL-databases. And so there's my data: Rows of rows of rows of meteorological data: Values, representing certain measurements at a certain station (Identified by a WMO number, not coordinates), at a certain time. Not every station measures every parameter, not every parameter is measured all the time. I store this data (30 years worth of hourly values, resulting in ~1 billion values) currently in MySQL. The continous growth and the forseeable addition of even more data give me a little headache. Reading about the document based NoSQL systems which seem to scale rather easily, I was wondering if NoSQL is a viable data storage concept for meteorological data too. Do you have any experience with this?

    Read the article

  • Finding the Formula for a Curve

    - by Mystagogue
    Is there a program that will take "response curve" values from me, and provide a formula that approximates the response curve? It would be cool if such a program would take a numeric "percent correct" (perhaps with a standard deviation) so that it returns simplified formulas when laxity is permissable, and more precise (viz. complex) formulas when the curve needs to be approximated closely. My interest is to play with the response curve values and "laxity" factor, until such a tool spits out a curve-fit formula simple enough that I know it will be high performance during machine computations.

    Read the article

  • Whats the difference between Paxos and W+R>=N in Cassandra?

    - by user1128016
    Dynamo-like databases (e.g. Cassandra) provide ability to enforce consistency by means of quorum, i.e. a number of synchronously written replicas (W) and a number of replicas to read (R) should be chosen in such a way that W+RN where N is a replication factor. On the other hand, PAXOS-based systems like Zookeeper are also used as a consistent fault-tolerant storage. What is the difference between these two approaches? Does PAXOS provide guarantees that are not provided by W+RN schema?

    Read the article

< Previous Page | 389 390 391 392 393 394 395 396 397 398 399 400  | Next Page >