Search Results

Search found 24642 results on 986 pages for 'language design'.

Page 246/986 | < Previous Page | 242 243 244 245 246 247 248 249 250 251 252 253  | Next Page >

• How to sketch out an event-driven system?

  - by Jordan

  I'm trying to design a system in Node.js (an attempt at solving one of my earlier problems, using Node's concurrency) but I'm running into trouble figuring out how to draw a plan of how the thing should operate. I'm getting very tripped up thinking in terms of callbacks instead of returned values. The flow isn't linear, and it's really boggling my ability to draft it. How does one draw out an operational flow for an event-driven system? I need something I can look at and say "Ok, yes, that's how it will work. I'll start it over here, and it will give me back these results over here." Pictures would be very helpful for this one. Thanks. Edit: I'm looking for something more granular than UML, specifically, something that will help me transition from a blocking and object-oriented programming structure, where I'm comfortable, to a non-blocking and event driven structure, where I'm unfamiliar.

  Read the article

• Python equivalent of IDL's stop and .reset

  - by Jamie

  Hi there, I'm relatively new to python but have a bit of experience using IDL. I was wondering if anyone knows if there are equivalent commands in python for IDL's stop and .reset commands. If I'm running some IDL script I wrote that I put a stop command in, essentially what it does is stop the script there and give me access to the command line in the middle of the script. So I have access to all the functions and variables that I defined before the stop command, which I find really useful for debugging. The .reset command I find extremely useful too. What it does is reset the the IDL environment (clears all variables, functions, etc.). It's as if I closed that session and opened a new one, but without having to exit and restart IDL. I find that if I'm trying to debug a script I wrote it's useful sometimes to start from scratch and not have to reset IDL (or python now). It would be useful also in python to be able to un-import any modules I had previously imported. Any help with these issues would be greatly appreciated. Cheers Related Python Drop into REPL Is it possible to go into ipython from code?

  Read the article

• How to show validation messages in MVC?

  - by Ian Boyd

  When a user tries to click:        Save and they have entered in some invalid data, i want to notify them. This can be with methods such as: directing their attention to the thing that needs their attention with a balloon hint automatically dropping down a combo-box triggering an animation showing a modal dialog box etc What is the mechanism where a controller tells the view to show a validation message for some controls, given that different views have different notification methods? p.s. the controller doesn't know the order that controls are physically arranged in the view (e.g. LTR locale wants to notify the user in a top-down-left-to-right visual order, while RTL locale wants to notify the user in a bottom-up-right-to-left order)

  Read the article

• Rewriting UNIX cal(1)

  - by dharmatech

  Hello, Today I was testing out SRFI 19 and wrote a simple version of the UNIX cal(1) command. Here's a version in R6RS Scheme which runs in Ikarus and Ypsilon. A few example runs. Schemers: How would you write it? Use your favorite implementation. Ruby and Python: I'm guessing that y'all have elegant date and time libraries. I'm sure you can put the Schemers to shame. ;-) Let's see what ya got. I'd also like to see Haskell and golfed versions. Is there a Stack Overflow tag for re-implementations of UNIX commands? :-) Ed

  Read the article

• 3 dimensional bin packing algorithms

  - by BuschnicK

  I'm faced with a 3 dimensional bin packing problem and am currently conducting some preliminary research as to which algorithms/heuristics are currently yielding the best results. Since the problem is NP hard I do not expect to find the optimal solution in every case, but I was wondering: 1) what are the best exact solvers? Branch and Bound? What problem instance sizes can I expect to solve with reasonable computing resources? 2) what are the best heuristic solvers? 3) What off-the-shelf solutions exist to conduct some experiments with?

  Read the article

• Low latency programming

  - by Sambatyon

  I've been reading a lot about low latency financial systems (especially since the famous case of corporate espionage) and the idea of low latency systems has been in my mind ever since. There are a million applications that can use what these guys are doing, so I would like to learn more about the topic. The thing is I cannot find anything valuable about the topic. Can anybody recommend books, sites, examples on low latency systems?

  Read the article

• Designing Database

  - by user548192

  Hello All, I need to design database with frontend as HTML. This is my first attempt to do this. What I need is, - User can input a word from HTML page, click submit I will query the word to get a URL from database and user sees that webpage(pointed by URL). Just enter word, submit and get the webpage displayed. People suggested using JSP/Access. I am new to everything. Can you please point out what exactly I need to do? Thanks a ton.

  Read the article

• What is the python "with" statement designed for?

  - by fmark

  I came across the Python with statement for the first time today. I've been using Python lightly for several months and didn't even of its existence! Given its somewhat obscure status, I thought it would be worth asking: What is the Python with statement designed to be used for? What do you use it for? Are their any gotchas I need to be aware of, or common anti-patterns associated with its use?

  Read the article

• How to implement a SIMPLE "You typed ACB, did you mean ABC?"

  - by marcgg

  I know this is not a straight up question, so if you need me to provide more information about the scope of it, let me know. There are a bunch of questions that address almost the same issue (they are linked here), but never the exact same one with the same kind of scope and objective - at least as far as I know. Context: I have a MP3 file with ID3 tags for artist name and song title. I have two tables Artists and Songs The ID3 tags might be slightly off (e.g. Mikaell Jacksonne) I'm using ASP.NET + C# and a MSSQL database I need to synchronize the MP3s with the database. Meaning: The user launches a script The script browses through all the MP3s The script says "Is 'Mikaell Jacksonne' 'Michael Jackson' YES/NO" The user pick and we start over Examples of what the system could find: In the database... SONGS = {"This is a great song title", "This is a song title"} ARTISTS = {"Michael Jackson"} Outputs... "This is a grt song title" did you mean "This is a great song title" ? "This is song title" did you mean "This is a song title" ? "This si a song title" did you mean "This is a song title" ? "This si song a title" did you mean "This is a song title" ? "Jackson, Michael" did you mean "Michael Jackson" ? "JacksonMichael" did you mean "Michael Jackson" ? "Michael Jacksno" did you mean "Michael Jackson" ? etc. I read some documentation from this /how-do-you-implement-a-did-you-mean and this is not exactly what I need since I don't want to check an entire dictionary. I also can't really use a web service since it's depending a lot on what I already have in my database. If possible I'd also like to avoid dealing with distances and other complicated things. I could use the google api (or something similar) to do this, meaning that the script will try spell checking and test it with the database, but I feel there could be a better solution since my database might end up being really specific with weird songs and artists, making spell checking useless. I could also try something like what has been explained on this post, using Soundex for c#. Using a regular spell checker won't work because I won't be using words but names and 'titles'. So my question is: is there a relatively simple way of doing this, and if so, what is it? Any kind of help would be appreciated. Thanks!

  Read the article

• Main pricing and support for custom client pricing (Database Architecture ideas help - Rails)

  - by slythic

  Hi all, I have a personal project I'm planning and I came to a small hurdle. I want to have an item with price that will be the default for all clients/users. However, in my business I have some clients that are grandfathered in to some special pricing. In the case of these grandfathered in cases, I'll manually plug their special price in my admin section. Then all they will see is their special pricing while the regular users/clients see the default price. What is the best and simplest way to design the back-end for this? FYI - I'll be using rails as my framework. Many thanks! -Tony

  Read the article

• Navigate between screens in WPF

  - by Greg R

  This should be a very basic design question, but for some reason it doesn't seem to be well documented (maybe due to its simplicity?). If I'm building a dashboard application in WPF that brig up different CRM tasks and I want to navigate between screens, is this the best way to do this, or is there a better way? So for example I have Log In Screen - Main Menu Screen - Screen to one of different utilities var orderManagerWindow = new MyXamlView(); var loginWindow = Application.Current.MainWindow; orderManagerWindow.Left = loginWindow.Left; orderManagerWindow.Top = loginWindow.Top; Application.Current.MainWindow = orderManagerWindow; orderManagerWindow.Show(); loginWindow.Close(); I would really appreciate help and suggestions!

  Read the article

• Code Golf - Banner Generation

  - by Claudiu

  When thanking someone, you don't want to just send them an e-mail saying "Thanks!", you want to have something FLASHY: Input: THANKS!! Output: TTT H H AAA N N K K SSS !!! !!! T H H A A NNN K K S !!! !!! T HHH AAA NNN KK SSS !!! !!! T H H A A N N K K S T H H A A N N K K SSS !!! !!! Write a program to generate a banner. You only have to generate upper-case A-Z along with spaces and exclamation points (what is a banner without an exclamation point?). All characters are made up of a 3x5 grid of the same character (so the S is a 3x5 grid made of S). All output should be on one row (so no newlines). Here are all the letters you need: Input: ABCDEFGHIJKL Output: AAA BBB CCC DD EEE FFF GGG H H III JJJ K K L A A B B C D D E F G H H I J K K L AAA BBB C D D EE FF G G HHH I J KK L A A B B C D D E F G G H H I J J K K L A A BBB CCC DD EEE F GGG H H III JJJ K K LLL Input: MNOPQRSTUVWX Output: M M N N OOO PPP QQQ RR SSS TTT U U V V W W X X MMM NNN O O P P Q Q R R S T U U V V W W X M M NNN O O PPP Q Q RR SSS T U U V V WWW X M M N N O O P QQQ R R S T U U V V WWW X M M N N OOO P QQQ R R SSS T UUU V WWW X X Input: YZ! Output: Y Y ZZZ !!! Y Y Z !!! YYY Z !!! Y Z YYY ZZZ !!! The winner is the shortest source code. Source code should read input from stdin, output to stdout. You can assume input will only contain [A-Z! ]. If you insult the user on incorrect input, you get a 10 character discount =P. I was going to require these exact 27 characters, but to make it more interesting, you can choose how you want them to look - whatever makes your code shorter! To prove that your letters do look like normal letters, show the output of the last three runs.

  Read the article

• Why use "foo" in coding examples? [closed]

  - by ThePower

  Possible Duplicates: To foo bar, or not to foo bar: that is the question. Bit of a general question here, but it's something I would like to know! Whenever I am looking for resolutions to my C# problems online, I always come across "foo" being used as an example. Does this represent anything or is it just one of those unexplained catchy object names, used by many people in examples?

  Read the article

• Bitwise Interval Arithmetic

  - by KennyTM

  I've recently read an interesting thread on the D newsgroup, which basically asks, Given two signed integers a ∈ [amin, amax], b ∈ [bmin, bmax], what is the tightest interval of a | b? I'm think if interval arithmetics can be applied on general bitwise operators (assuming infinite bits). The bitwise-NOT and shifts are trivial since they just corresponds to -1 − x and 2n x. But bitwise-AND/OR are a lot trickier, due to the mix of bitwise and arithmetic properties. Is there a polynomial-time algorithm to compute the intervals of bitwise-AND/OR? Note: Assume all bitwise operations run in linear time (of number of bits), and test/set a bit is constant time. The brute-force algorithm runs in exponential time. Because ~(a | b) = ~a & ~b and a ^ b = (a | b) & ~(a & b), solving the bitwise-AND and -NOT problem implies bitwise-OR and -XOR are done. Although the content of that thread suggests min{a | b} = max(amin, bmin), it is not the tightest bound. Just consider [2, 3] | [8, 9] = [10, 11].)

  Read the article

• [MSIL] Variable comparison

  - by alexn

  Hi, The following C#-snippet: var x = 1; var y = 1; if (x == y) Console.Write("True"); Generates this MSIL: .locals init ( [0] int32 x, [1] int32 y, [2] bool CS$4$0000) L_0000: nop L_0001: ldc.i4.1 L_0002: stloc.0 L_0003: ldc.i4.1 L_0004: stloc.1 L_0005: ldloc.0 L_0006: ldloc.1 L_0007: ceq L_0009: ldc.i4.0 L_000a: ceq L_000c: stloc.2 L_000d: ldloc.2 L_000e: brtrue.s L_001b L_0010: ldstr "True" L_0015: call void [mscorlib]System.Console::Write(string) L_001a: nop L_001b: ret Why is there two ceq calls? Thanks

  Read the article

• Main pricing and support for individual client pricing (Database Architecture ideas help - Rails)

  - by slythic

  Hi all, I have a personal project I'm planning and I came to a small hurdle. I want to have an item with price that will be the default for all clients/users. However, in my business I have some clients that are grandfathered in to some special pricing. In the case of these grandfathered in cases, I'll manually plug their special price in my admin section. Then all they will see is their special pricing while the regular users/clients see the default price. What is the best and simplest way to design the back-end for this? FYI - I'll be using rails as my framework. Many thanks! -Tony

  Read the article

• Working with expression AST:s

  - by Marcus

  Hi, Is there any best practice when working with AST:s? I have a parsed expression AST. ConstantExpression, BinaryExpression etc. I want to populate a GUI-dialog with information from the AST, and it's here where I get kinda confused because my code gets pretty messy. Example: expression = "Var1 > 10 AND Var2 < 20" I want to populate two textboxes with value 10 resp. 20 from the AST. What I'm doing now is a recursive method that checks for correct child expression-types (with .Net Is-operator) and acts accordingly and the code is really "smelly" :) Is there any design pattern, like Visitor or such, that makes this somewhat easier/more readable/maintainable ?

  Read the article

• Scalable / Parallel Large Graph Analysis Library?

  - by Joel Hoff

  I am looking for good recommendations for scalable and/or parallel large graph analysis libraries in various languages. The problems I am working on involve significant computational analysis of graphs/networks with 1-100 million nodes and 10 million to 1+ billion edges. The largest SMP computer I am using has 256 GB memory, but I also have access to an HPC cluster with 1000 cores, 2 TB aggregate memory, and MPI for communication. I am primarily looking for scalable, high-performance graph libraries that could be used in either single or multi-threaded scenarios, but parallel analysis libraries based on MPI or a similar protocol for communication and/or distributed memory are also of interest for high-end problems. Target programming languages include C++, C, Java, and Python. My research to-date has come up with the following possible solutions for these languages: C++ -- The most viable solutions appear to be the Boost Graph Library and Parallel Boost Graph Library. I have looked briefly at MTGL, but it is currently slanted more toward massively multithreaded hardware architectures like the Cray XMT. C - igraph and SNAP (Small-world Network Analysis and Partitioning); latter uses OpenMP for parallelism on SMP systems. Java - I have found no parallel libraries here yet, but JGraphT and perhaps JUNG are leading contenders in the non-parallel space. Python - igraph and NetworkX look like the most solid options, though neither is parallel. There used to be Python bindings for BGL, but these are now unsupported; last release in 2005 looks stale now. Other topics here on SO that I've looked at have discussed graph libraries in C++, Java, Python, and other languages. However, none of these topics focused significantly on scalability. Does anyone have recommendations they can offer based on experience with any of the above or other library packages when applied to large graph analysis problems? Performance, scalability, and code stability/maturity are my primary concerns. Most of the specialized algorithms will be developed by my team with the exception of any graph-oriented parallel communication or distributed memory frameworks (where the graph state is distributed across a cluster).

  Read the article

• how to localize a table with multiple text entries?

  - by rap-uvic

  Hello, I'm writing a web app which will allow creation of events. An event can have a title as well as a description amongst other things. The app needs to be multilingual. So I have 4 tables for localization: ResourceTypes, ResourceKeys, Resources, and Locales. A resource key can have multiple values in Resources table for different locales. So Resources is a many to many table between ResourceKeys and Locales. So in the event table I want to have a resourceKey for its title as well as a resourceKey for its description. So my question is, is it OK from database-design perspective to have two foreign keys from a table into another table? Has anybody used a better approach in such a scenario?

  Read the article

• Who likes short shorts?

  - by kiwicptn

  I got $2 change instead of $3 today and that got me thinking about short for some reason. What can do (these days ;-p) with a variable of the short primitive type (16 bits signed)? Any good reason to keep them around?

  Read the article

• Pair programming: How should the pairs be chosen?

  - by Jon Seigel

  This topic has been covered peripherally in bits and pieces in some of the other pair-programming questions, but I want to (a) consolidate this knowledge into a separate question, and, most importantly, (b) go into much more depth on the subject. From the perspective of being an effective manager, how should pairs be arranged for pair programming to maximize both the happiness and productivity of the overall team? Some ideas to get started: Should two people never be paired (because of personalities, for example)? How much overlap in skillsets is needed? How much disconnect in skillsets is too much to overcome? (No two people will overlap 100%, and a disconnect in skills can be very beneficial to both people.) Should everyone pair with everyone else on a fixed/rotating basis? Should certain pairs be arranged to accomplish specific tasks? How important a role does HR play when growing or reorganizing the team?

  Read the article

• Is it a good practice to suppress warnings?

  - by Chris Cooper

  Sometimes while writing Java in Eclipse, I write code that generates warnings. A common one is this, which I get when extending the Exception class: public class NumberDivideException extends Exception { public NumberDivideException() { super("Illegal complex number operation!"); } public NumberDivideException(String s) { super(s); } } // end NumberDivideException The warning: The serializable class NumberDivideException does not declare a static final serialVersionUID field of type long. I know this warning is caused by my failure to... well, it says right above. I could solve it by including the serialVersionUID, but this is a one hour tiny assignment for school; I don't plan on serializing it anytime soon... The other option, of course, is to let Eclipse add @SuppressWarnings("serial"). But every time my mouse hovers over the Suppress option, I feel a little guilty. For programming in general, is it a good habit to suppress warnings? (Also, as a side question, is adding a "generated" serialVersionUID like serialVersionUID = -1049317663306637382L; the proper way to add a serialVersionUID, or do I have to determine the number some other way?)

  Read the article

• How can I add forward class references used in the -Swift.h header?

  - by Bill

  I'm integrating Swift code into a large Objective-C project, but I'm running into problems when my Swift code refers to Objective-C classes. For example, suppose I have: An Objective-C class called MyTableViewController An Objective-C class called DeletionWorkflow I declared a Swift class as follows: class DeletionVC: MyTableViewController { let deleteWorkflow: DeletionWorkflow ... } If I now try to use this class by importing ProjectName-Swift.h into Objective-C code, I get undefined symbol errors for both MyTableViewController and DeletionWorkflow. I can fix the problem in that individual source file by importing DeletionWorkflow.h and MyTableViewController.h before I import ProjectName-Swift.h but this doesn't scale up to a large project where I want my Swift and Objective-C to interact often. Is there a way to add forward class references to ProjectName-Swift.h so that these errors don't occur when I try to use Swift classes from Objective-C code in my app?

  Read the article

• How do functional programming languages work?

  - by eSKay

  I was just reading this excellent post, and got some better understanding of what exactly object oriented programming is, how Java implements it in one extreme manner, and how functional programming languages are a contrast. What I was thinking is this: if functional programming languages cannot save any state, how do they do some simple stuff like reading input from a user (I mean how do they "store" it), or storing any data for that matter? For example - how would this simple C thing translate to any functional programming language, for example haskell? #include<stdio.h> int main() { int no; scanf("%d",&no); return 0; }

  Read the article

• Why is Self assignable in Delphi?

  - by mjustin

  This code in a GUI application compiles and runs: procedure TForm1.Button1Click(Sender: TObject); begin Self := TForm1.Create(Owner); end; (tested with Delphi 6 and 2009) why is Self writeable and not read-only? in which situations could this be useful? Edit: is this also possible in Delphi Prism? (I think yes it is, see here) Update: Delphi applications/libraries which make use of Self assignment: python4delphi

  Read the article

< Previous Page | 242 243 244 245 246 247 248 249 250 251 252 253  | Next Page >