Search Results

Search found 1703 results on 69 pages for 'grails constraints'.

Page 62/69 | < Previous Page | 58 59 60 61 62 63 64 65 66 67 68 69  | Next Page >

• GADTs and Scrap your Boilerplate

  - by finnsson

  I'm writing a XML (de)serializer using Text.XML.Light and Scrap your Boilerplate (at http://github.com/finnsson/Text.XML.Generic) and so far I got working code for "normal" ADTs but I'm stuck at deserializing GADTs. I got the GADT data DataBox where DataBox :: (Show d, Eq d, Data d) => d -> DataBox and I'm trying to get this to compile instance Data DataBox where gfoldl k z (DataBox d) = z DataBox `k` d gunfold k z c = k (z DataBox) -- not OK toConstr (DataBox d) = toConstr d dataTypeOf (DataBox d) = dataTypeOf d but I can't figure out how to implement gunfold for DataBox. The error message is Text/XML/Generic.hs:274:23: Ambiguous type variable `b' in the constraints: `Eq b' arising from a use of `DataBox' at Text/XML/Generic.hs:274:23-29 `Show b' arising from a use of `DataBox' at Text/XML/Generic.hs:274:23-29 `Data b' arising from a use of `k' at Text/XML/Generic.hs:274:18-30 Probable fix: add a type signature that fixes these type variable(s) It's complaining about not being able to figure out the data type of b. I'm also trying to implement dataCast1 and dataCast2 but I think I can live without them (i.e. an incorrect implementation). I guess my questions are: Is it possible to combine GADTs with Scrap your Boilerplate? If so: how do you implement gunfold for a GADT?

  Read the article

• Measuring how "heavily linked" a node is in a graph

  - by Eduardo León

  I have posted this question at MathOverflow.com as well. I am no mathematician and English is not my first language, so please excuse me if my question is too stupid, it is poorly phrased, or both. I am developing a program that creates timetables. My timetable-creating algorithm, besides creating the timetable, also creates a graph whose nodes represent each class I have already programmed, and whose arcs represent which pairs of classes should not be programmed at the same time, even if they have to be reprogrammed. The more "heavily linked" a node is, the more inflexible its associated class is with respect to being reprogrammed. Sometimes, in the middle of the process, there will be no option but to reprogram a class that has already been programmed. I want my program to be able to choose a class that, if reprogrammed, affects the least possible number of other already-programmed classes. That would mean choosing a node in the graph that is "not very heavily linked", subject to some constraints with respect to which nodes can be chosen. EDIT: The question was... Do you know any algorithm that measures how "heavily linked" a node is?

  Read the article

• Why is Routes.rb not loading the IPs from cache?

  - by Christian Fazzini

  I am testing this in local. My ip is 127.0.0.1. The ip_permissions table, is empty. When I browse the site, everything works as expected. Now, I want to simulate browsing the site with a banned IP. So I add the IP into the ip_permissions table via: IpPermission.create!(:ip => '127.0.0.1', :note => 'foobar', :category => 'blacklist') In Rails console, I clear the cache via; Rails.cache.clear. I browse the site. I don't get sent to pages#blacklist. If I restart the server. And browse the site, then I get sent to pages#blacklist. Why do I need to restart the server every time the ip_permissions table is updated? Shouldn't it fetch it based on cache? Routes look like: class BlacklistConstraint def initialize @blacklist = IpPermission.blacklist end def matches?(request) @blacklist.map { |b| b.ip }.include? request.remote_ip end end Foobar::Application.routes.draw do match '/(*path)' => 'pages#blacklist', :constraints => BlacklistConstraint.new .... end My model looks like: class IpPermission < ActiveRecord::Base validates_presence_of :ip, :note, :category validates_uniqueness_of :ip, :scope => [:category] validates :category, :inclusion => { :in => ['whitelist', 'blacklist'] } def self.whitelist Rails.cache.fetch('whitelist', :expires_in => 1.month) { self.where(:category => 'whitelist').all } end def self.blacklist Rails.cache.fetch('blacklist', :expires_in => 1.month) { self.where(:category => 'blacklist').all } end end

  Read the article

• Using Linq-To-SQL I'm getting some weird behavior doing text searches with the .Contains method. Loo

  - by Nate Bross

  I have a table, where I need to do a case insensitive search on a text field. If I run this query in LinqPad directly on my database, it works as expected Table.Where(tbl => tbl.Title.Contains("StringWithAnyCase")) // also, adding in the same constraints I'm using in my repository works in LinqPad // Table.Where(tbl => tbl.Title.Contains("StringWithAnyCase") && tbl.IsActive == true) In my application, I've got a repository which exposes IQueryable objects which does some initial filtering and it looks like this var dc = new MyDataContext(); public IQueryable<Table> GetAllTables() { var ret = dc.Tables.Where(t => t.IsActive == true); return ret; } In the controller (its an MVC app) I use code like this in an attempt to mimic the LinqPad query: var rpo = new RepositoryOfTable(); var tables = rpo.GetAllTables(); // for some reason, this does a CASE SENSITIVE search which is NOT what I want. tables = tables.Where(tbl => tbl.Title.Contains("StringWithAnyCase"); return View(tables); The column is defiend as an nvarchar(50) in SQL Server 2008. Any help or guidance is greatly appreciated!

  Read the article

• Avoiding repeated subqueries when 'WITH' is unavailable

  - by EloquentGeek

  MySQL v5.0.58. Tables, with foreign key constraints etc and other non-relevant details omitted for brevity: CREATE TABLE `fixture` ( `id` int(11) NOT NULL auto_increment, `competition_id` int(11) NOT NULL, `name` varchar(50) NOT NULL, `scheduled` datetime default NULL, `played` datetime default NULL, PRIMARY KEY (`id`) ); CREATE TABLE `result` ( `id` int(11) NOT NULL auto_increment, `fixture_id` int(11) NOT NULL, `team_id` int(11) NOT NULL, `score` int(11) NOT NULL, `place` int(11) NOT NULL, PRIMARY KEY (`id`) ); CREATE TABLE `team` ( `id` int(11) NOT NULL auto_increment, `name` varchar(50) NOT NULL, PRIMARY KEY (`id`) ); Where: A draw will set result.place to 0 result.place will otherwise contain an integer representing first place, second place, and so on The task is to return a string describing the most recently played result in a given competition for a given team. The format should be "def Team X,Team Y" if the given team was victorious, "lost to Team X" if the given team lost, and "drew with Team X" if there was a draw. And yes, in theory there could be more than two teams per fixture (though 1 v 1 will be the most common case). This works, but feels really inefficient: SELECT CONCAT( (SELECT CASE `result`.`place` WHEN 0 THEN "drew with" WHEN 1 THEN "def" ELSE "lost to" END FROM `result` WHERE `result`.`fixture_id` = (SELECT `fixture`.`id` FROM `fixture` LEFT JOIN `result` ON `result`.`fixture_id` = `fixture`.`id` WHERE `fixture`.`competition_id` = 2 AND `result`.`team_id` = 1 ORDER BY `fixture`.`played` DESC LIMIT 1) AND `result`.`team_id` = 1), ' ', (SELECT GROUP_CONCAT(`team`.`name`) FROM `fixture` LEFT JOIN `result` ON `result`.`fixture_id` = `fixture`.`id` LEFT JOIN `team` ON `result`.`team_id` = `team`.`id` WHERE `fixture`.`id` = (SELECT `fixture`.`id` FROM `fixture` LEFT JOIN `result` ON `result`.`fixture_id` = `fixture`.`id` WHERE `fixture`.`competition_id` = 2 AND `result`.`team_id` = 1 ORDER BY `fixture`.`played` DESC LIMIT 1) AND `team`.`id` != 1) ) Have I missed something really obvious, or should I simply not try to do this in one query? Or does the current difficulty reflect a poor table design?

  Read the article

• facebook Hacker cup: studious Student problem.

  - by smartmuki

  During the qualification round, the following question was asked: You've been given a list of words to study and memorize. Being a diligent student of language and the arts, you've decided to not study them at all and instead make up pointless games based on them. One game you've come up with is to see how you can concatenate the words to generate the lexicographically lowest possible string. Input As input for playing this game you will receive a text file containing an integer N, the number of word sets you need to play your game against. This will be followed by N word sets, each starting with an integer M, the number of words in the set, followed by M words. All tokens in the input will be separated by some whitespace and, aside from N and M, will consist entirely of lowercase letters. Output Your submission should contain the lexicographically shortest strings for each corresponding word set, one per line and in order. Constraints 1 <= N <= 100 1 <= M <= 9 1 <= all word lengths <= 10 Example input 5 6 facebook hacker cup for studious students 5 k duz q rc lvraw 5 mybea zdr yubx xe dyroiy 5 jibw ji jp bw jibw 5 uiuy hopji li j dcyi Example output cupfacebookforhackerstudentsstudious duzklvrawqrc dyroiymybeaxeyubxzdr bwjibwjibwjijp dcyihopjijliuiuy The program I wrote goes as: chomp($numberElements=<STDIN>); for(my $i=0; $i < $numberElements; $i++) { my $string; chomp ($string = <STDIN>); my @array=split(/\s+/,$string); my $number=shift @array; @sorted=sort @array; $sortedStr=join("",@sorted); push(@data,$sortedStr); } foreach (@data) { print "$_\n"; } The program gives the correct output for the given test cases but still facebook shows it to be incorrect. Is there something wrong with the program??

  Read the article

• best database design for city zip & state tables

  - by ryan a

  My application will need to reference addresses. Street info will be stored with my main objects but the rest needs to be stored seperately to reduce redundancy. How should I store/retrieve ZIPs, cities and states? Here are some of my ideas. single table solution (cant do relationships) [locations] locationID locationParent (FK for locationID - 0 for state entries) locationName (city, state) locationZIP two tables (with relationships, FK constraints, ref integrity) [state] stateID stateName [city] cityID stateID (FK for state.stateID) cityName zipCode three tables [state] stateID stateName [city] cityID stateID (FK for state.stateID) cityName [zip] zipID cityID (FK for city.cityID) zipName Then I read into ZIP codes amd how they are assigned. They aren't specifically related to cities. Some cities have more than one ZIP (ok will still work) but some ZIPs are in more than one city (oh snap) and some other ZIPs (very few) are in more than one state! Also some ZIPs are not even in the same state as the address they belong to at all. Seems ZIPs are made for carrier route identification and some remote places are best served by post offices in neighboring cities or states. Does anybody know of a good (not perfect) solution that takes this into consideration to minimize discrepencies as the database grows?

  Read the article

• Will this cause a problem with different runtimes with DLL?

  - by Milo

  My gui application supports polymorphic timed events so that means that the user calls new, and the gui calls delete. This can create a problem if the runtimes are incompatible. So I was told a proposed solution would be this: class base; class Deallocator { void operator()(base* ptr) { delete ptr; } } class base { public: base(Deallocator dealloc) { m_deleteFunc = dealloc; } ~base() { m_deleteFunc(this); } private: Deallocator m_deleteFunc; } int main { Deallocator deletefunc; base baseObj(deletefunc); } While this is a good solution, it does demand that the user create a Deallocator object which I do not want. I was however wondering if I provided a Deallocator to each derived class: eg class derived : public base { Deallocator dealloc; public: Derived() : base(dealloc); { } }; I think this still does not work though. The constraint is that: The addTimedEvent() function is part of the Widget class which is also in the dll, but it is instanced by the user. The other constraint is that some classes which derive from Widget call this function with their own timed event classes. Given that "he who called new must call delete" what could work given these constraints? Thanks

  Read the article

• Computing, storing, and retrieving values to and from an N-Dimensional matrix

  - by Adam S

  This question is probably quite different from what you are used to reading here - I hope it can provide a fun challenge. Essentially I have an algorithm that uses 5(or more) variables to compute a single value, called outcome. Now I have to implement this algorithm on an embedded device which has no memory limitations, but has very harsh processing constraints. Because of this, I would like to run a calculation engine which computes outcome for, say, 20 different values of each variable and stores this information in a file. You may think of this as a 5(or more)-dimensional matrix or 5(or more)-dimensional array, each dimension being 20 entries long. In any modern language, filling this array is as simple as having 5(or more) nested for loops. The tricky part is that I need to dump these values into a file that can then be placed onto the embedded device so that the device can use it as a lookup table. The questions now, are: What format(s) might be acceptable for storing the data? What programs (MATLAB, C#, etc) might be best suited to compute the data? C# must be used to import the data on the device - is this possible given your answer to #1?

  Read the article

• Capacity Allocation

  - by user1708730

  I am new to VB in Excel. I have a unique requirement for capacity allocation which I want to automate using excel VB and facing hard time doing so, hope you can help. The objective is to maximize profit by allocating maximum capacity to those products which have highest profit potential first. Every Month I get demand along with backlogs of previous month. I need to allocate capacity to backlogs of previous month first and then only the remaining capacity for fresh demand. There are two primary constraints: 1.The number of working days in a month (variable) 2. Not all products can be made on every production line and out of same product may be different for each production line Also there will be losses whenever there is a change over from one SKU to another depending upon the Variant Type and size of next product. If there is variant change then 8 hours of production loss needs to be accounted and 4 hours in case of size change(8 hours in case of both). I have attached sample data(Actual data has 10 production lines and 50 products) https://rapidshare.com/files/1822719405/Sample%20Data.xlsx?bin=1 Thanks in advance for help!

  Read the article

• Datastructure choices for highspeed and memory efficient detection of duplicate of strings

  - by Jonathan Holland

  I have a interesting problem that could be solved in a number of ways: I have a function that takes in a string. If this function has never seen this string before, it needs to perform some processing. If the function has seen the string before, it needs to skip processing. After a specified amount of time, the function should accept duplicate strings. This function may be called thousands of time per second, and the string data may be very large. This is a highly abstracted explanation of the real application, just trying to get down to the core concept for the purpose of the question. The function will need to store state in order to detect duplicates. It also will need to store an associated timestamp in order to expire duplicates. It does NOT need to store the strings, a unique hash of the string would be fine, providing there is no false positives due to collisions (Use a perfect hash?), and the hash function was performant enough. The naive implementation would be simply (in C#): Dictionary<String,DateTime> though in the interest of lowering memory footprint and potentially increasing performance I'm evaluating a custom data structures to handle this instead of a basic hashtable. So, given these constraints, what would you use? EDIT, some additional information that might change proposed implementations: 99% of the strings will not be duplicates. Almost all of the duplicates will arrive back to back, or nearly sequentially. In the real world, the function will be called from multiple worker threads, so state management will need to be synchronized.

  Read the article

• Is long long in C++ known to be very nasty in terms of precision?

  - by Kevin

  The Given Problem: Given a theater with n rows, m seats, and a list of seats that are reserved. Given these values, determine how many ways two friends can sit together in the same row. So, if the theater was a size of 2x3 and the very first seat in the first row was reserved, there would be 3 different seatings that these two guys can take. The Problem That I'm Dealing With The function itself is supposed to return the number of seatings that there are based on these constraints. The return value is a long long. I've gone through my code many many times...and I'm pretty sure that it's right. All I'm doing is incrementing this one value. However, ALL of the values that my function return differ from the actual solution by 1 or 2. Any ideas? And if you think that it's just something wrong with my code, please tell me. I don't mind being called an idiot just as long as I learn something.

  Read the article

• Sql Server 2005 Check Constraint not being applied in execution when using variables

  - by DarylS

  Here is some SQL sample code: --Create 2 Sales tables with constraints based on the saledate create table Sales1(SaleDate datetime, Amount money) ALTER TABLE dbo.Sales1 ADD CONSTRAINT CK_Sales1 CHECK (([SaleDate]>='01 May 2010')) GO create table Sales2(SaleDate datetime, Amount money) ALTER TABLE dbo.Sales2 ADD CONSTRAINT CK_Sales2 CHECK (([SaleDate]<'01 May 2010')) GO --Insert some data into Sales1 insert into Sales1 (SaleDate, Amount) values ('02 May 2010', 50) insert into Sales1 (SaleDate, Amount) values ('03 May 2010', 60) GO --Insert some data into Sales2 insert into Sales2 (SaleDate, Amount) values ('30 Mar 2010', 10) insert into Sales2 (SaleDate, Amount) values ('31 Mar 2010', 20) GO --Create a view that combines these 2 tables create VIEW [dbo].[Sales] AS SELECT SaleDate, Amount FROM Sales1 UNION ALL SELECT SaleDate, Amount FROM Sales2 GO --Get the results --Query 1 select * from Sales where SaleDate < '31 Mar 2010' -- if you look at the execution plan this query only looks at Sales2 (Which is good) --Query 2 DECLARE @SaleDate datetime SET @SaleDate = '31 Mar 2010' select * from Sales where SaleDate < @SaleDate -- if you look at the execution plan this query looks at Sales1 and Sales2 (Which is NOT good) Looking at the execution plan you will see that the two queries are differnt. For Query 1 the only table that is accessed is Sales1 (which is good). For Query 2 both tables are accessed (Which is bad). Why are these execution plans different, and how do i get Query 2 to only access the relevant table when variables are used? I have tried to add indexes for the SaleDate column and that does not seem to help.

  Read the article

• Is the Subversion 'stack' a realistic alternative to Team Foundation Server?

  - by Robert S.

  I'm evaluating Microsoft Team Foundation Server for my customer, who currently uses Visual SourceSafe and nothing else. They have explicitly expressed a desire to implement a more rigid and process-driven environment as their application is in production and they have future releases to consider. The particular areas I'm trying to cover are: Configuration management (e.g., source control) Change management (workflow and doco for change requests, tasks) Release management (builds and deployments) Incident and problem management (issues and bugs) Document management (similar to source control, but available via web) Code analysis constraints on check-ins A testing framework Reporting Visual Studio 2008 integration TFS does all of these things quite well, but it's expensive and complex to maintain, and the inexpensive Workgroup edition doesn't scale. We don't get TFS as part of our MSDN subscription. Those problems can be overcome, but before I tell my customer to go the TFS route, which in itself isn't a terrible thing, I wanted to evaluate the alternatives. I know Subversion is often suggested for its configuration management/source control, but what about the other areas? Would a combination of Subversion/NUnit/Wiki/CruiseControl/NAnt/something else satisfy all of these requirements? What tools do I need to include in my evaluation? Or should I just bite the bullet and go with TFS since we're already invested in the Microsoft stack?

  Read the article

• Django Save Incomplete Progress on Form

  - by jimbob

  I have a django webapp with multiple users logging in and fill in a form. Some users may start filling in a form and lack some required data (e.g., a grant #) needed to validate the form (and before we can start working on it). I want them to be able to fill out the form and have an option to save the partial info (so another day they can log back in and complete it) or submit the full info undergoing validation. Currently I'm using ModelForm for all the forms I use, and the Model has constraints to ensure valid data (e.g., the grant # has to be unique). However, I want them to be able to save this intermediary data without undergoing any validation. The solution I've thought of seems rather inelegant and un-django-ey: create a "Save Partial Form" button that saves the POST dictionary converts it to a shelf file and create a "SavedPartialForm" model connecting the user to partial forms saved in the shelf. Does this seem sensible? Is there a better way to save the POST dict directly into the db? Or is an add-on module that does this partial-save of a form (which seems to be a fairly common activity with webforms)? My biggest concern with my method is I want to eventually be able to do this form-autosave automatically (say every 10 minutes) in some ajax/jquery method without actually pressing a button and sending the POST request (e.g., so the user isn't redirected off the page when autosave is triggered). I'm not that familiar with jquery and am wondering if it would be possible to do this.

  Read the article

• C++ RPC library suggestions

  - by Oxsnarder

  I'm looking for suggestions regarding RPC libraries implemented in C++, for C++ developers. Some requirements constraints: Should work on both linux/unix and win32 systems Be able to execute free function and class methods Hopefully written in modern C++ not 90's/java-esque C++ Be able to function over networks and hetrogenous architectures Not too slow or inefficient Hopefully provide interfaces for TR1 style std::function's et al. My example usage is to invoke the free function foo on a remote machine. ---snip--- // foo translation unit int foo(int i, int j) { return i + j; } ---snip--- ---snip--- // client side main int main() { //register foo on client and server //setup necassary connections and states int result; if (RPCmechanism.invoke("foo",4,9,result)) std::cout << "foo(4,9) = " result << std::endl; else std::cout << "failed to invoke foo(4,9)!" << std::endl; return 0; } ---snip--- Something that can achieve the above or similar would be great.

  Read the article

• Security strategies for storing password on disk

  - by Mike

  I am building a suite of batch jobs that require regular access to a database, running on a Solaris 10 machine. Because of (unchangable) design constraints, we are required use a certain program to connect to it. Said interface requires us to pass a plain-text password over a command line to connect to the database. This is a terrible security practice, but we are stuck with it. I am trying to make sure things are properly secured on our end. Since the processing is automated (ie, we can't prompt for a password), and I can't store anything outside the disk, I need a strategy for storing our password securely. Here are some basic rules The system has multiple users. We can assume that our permissions are properly enforced (ie, if a file with a is chmod'd to 600, it won't be publically readable) I don't mind anyone with superuser access looking at our stored password Here is what i've got so far Store password in password.txt $chmod 600 password.txt Process reads from password.txt when it's needed Buffer overwritten with zeros when it's no longer needed Although I'm sure there is a better way.

  Read the article

• Should core application configuration be stored in the database, and if so what should be done to se

  - by Rl

  I'm writing an application around a lot of hierarchical data. Currently the hierarchy is fixed, but it's likely that new items will be added to the hierarchy in the future. (please let them be leaves) My current application and database design is fairly generic and nothing dealing with specific nodes in the hierarchy is hardcoded, with the exception of validation and lookup functions written to retrieve external data from each node's particular database. This pleases me from a design point of view, but I'm nervous at the realization that the entire application rests on a handful of records in the database. I'm also frustrated that I have to enforce certain aspects of data integrity with database triggers rather than by foreign key constraints (an example is where several different nodes in the hierarchy have their own proprietary IDs and I store them in a single column which, when coupled with the node ID can be used to locate the foreign data). I'm starting to wonder whether it may have been appropriate to simply hardcoded these known nodes into the system so that it would be more "type safe" and less generic. How does one know when something should be hardcoded, and when it should be a configuration item? Is it just a cost-benefit analysis of clarity/safety now vs less work later, or am I missing some metric I should be using to determine whether or not this is appropriate. The steps I'm taking to protect these valuable configurations are to add triggers that prevent updates/deletes. The database user that this application uses will only have the ability to manipulate data through stored procedures. What else can I do?

  Read the article

• Strange type-related error

  - by vsb

  I wrote following program: isPrime x = and [x `mod` i /= 0 | i <- [2 .. truncate (sqrt x)]] primes = filter isPrime [1 .. ] it should construct list of prime numbers. But I got this error: [1 of 1] Compiling Main ( 7/main.hs, interpreted ) 7/main.hs:3:16: Ambiguous type variable `a' in the constraints: `Floating a' arising from a use of `isPrime' at 7/main.hs:3:16-22 `RealFrac a' arising from a use of `isPrime' at 7/main.hs:3:16-22 `Integral a' arising from a use of `isPrime' at 7/main.hs:3:16-22 Possible cause: the monomorphism restriction applied to the following: primes :: [a] (bound at 7/main.hs:3:0) Probable fix: give these definition(s) an explicit type signature or use -XNoMonomorphismRestriction Failed, modules loaded: none. If I specify signature for isPrime function explicitly: isPrime :: Integer -> Bool isPrime x = and [x `mod` i /= 0 | i <- [2 .. truncate (sqrt x)]] I can't even compile isPrime function: [1 of 1] Compiling Main ( 7/main.hs, interpreted ) 7/main.hs:2:45: No instance for (RealFrac Integer) arising from a use of `truncate' at 7/main.hs:2:45-61 Possible fix: add an instance declaration for (RealFrac Integer) In the expression: truncate (sqrt x) In the expression: [2 .. truncate (sqrt x)] In a stmt of a list comprehension: i <- [2 .. truncate (sqrt x)] 7/main.hs:2:55: No instance for (Floating Integer) arising from a use of `sqrt' at 7/main.hs:2:55-60 Possible fix: add an instance declaration for (Floating Integer) In the first argument of `truncate', namely `(sqrt x)' In the expression: truncate (sqrt x) In the expression: [2 .. truncate (sqrt x)] Failed, modules loaded: none. Can you help me understand, why am I getting these errors?

  Read the article

• templated method on T inside a templated class on TT : Is that possible/correct.

  - by paercebal

  I have a class MyClass which is templated on typename T. But inside, I want a method which is templated on another type TT (which is unrelated to T). After reading/tinkering, I found the following notation: template <typename T> class MyClass { public : template<typename TT> void MyMethod(const TT & param) ; } ; For stylistic reasons (I like to have my templated class declaration in one header file, and the method definitions in another header file), I won't define the method inside the class declaration. So, I have to write it as: template <typename T> // this is the type of the class template <typename TT> // this is the type of the method void MyClass<T>::MyMethod(const TT & param) { // etc. } I knew I had to "declare" the typenames used in the method, but didn't know how exactly, and found through trials and errors. The code above compiles on Visual C++ 2008, but: Is this the correct way to have a method templated on TT inside a class templated on T? As a bonus: Are there hidden problems/surprises/constraints behind this kind of code? (I guess the specializations can be quite amusing to write)

  Read the article

• Optimize Duplicate Detection

  - by Dave Jarvis

  Background This is an optimization problem. Oracle Forms XML files have elements such as: <Trigger TriggerName="name" TriggerText="SELECT * FROM DUAL" ... /> Where the TriggerText is arbitrary SQL code. Each SQL statement has been extracted into uniquely named files such as: sql/module=DIAL_ACCESS+trigger=KEY-LISTVAL+filename=d_access.fmb.sql sql/module=REP_PAT_SEEN+trigger=KEY-LISTVAL+filename=rep_pat_seen.fmb.sql I wrote a script to generate a list of exact duplicates using a brute force approach. Problem There are 37,497 files to compare against each other; it takes 8 minutes to compare one file against all the others. Logically, if A = B and A = C, then there is no need to check if B = C. So the problem is: how do you eliminate the redundant comparisons? The script will complete in approximately 208 days. Script Source Code The comparison script is as follows: #!/bin/bash echo Loading directory ... for i in $(find sql/ -type f -name \*.sql); do echo Comparing $i ... for j in $(find sql/ -type f -name \*.sql); do if [ "$i" = "$j" ]; then continue; fi # Case insensitive compare, ignore spaces diff -IEbwBaq $i $j > /dev/null # 0 = no difference (i.e., duplicate code) if [ $? = 0 ]; then echo $i :: $j >> clones.txt fi done done Question How would you optimize the script so that checking for cloned code is a few orders of magnitude faster? System Constraints Using a quad-core CPU with an SSD; trying to avoid using cloud services if possible. The system is a Windows-based machine with Cygwin installed -- algorithms or solutions in other languages are welcome. Thank you!

  Read the article

• Handling text menu in Python

  - by PulpFiction

  Hi all. I am trying to create a text based menu in Python. Here is the code: #!/usr/bin/env python def testcaseOutput(): print '1. Add. 2. Subtract. 3. Divide. 4. Multiply' try: answer = int(raw_input('Enter a value (1 - 4) >. ')) except ValueError: print 'Invalid input. Enter a value between 1 -4 .' testcaseOutput() if answer in range(1, 5): return answer else: print 'Invalid input. Enter a value between 1 - 4.' testcaseOutput() My question: When the user enters an invalid input, i.e. not a number, I want this function to get called again. So I used the recursive approach which I think is bad design. I use that approach again in the if answer in range(1, 5). Is there any other way to handle this? I need the prompt called again when there is an invalid input. Also, is there any way I can club the two constraints: check whether input is a number and check whether the number is in the range(1,5) together? As you can see, I am checking that individually.

  Read the article

• Can you explain this generics behavior and if I have a workaround?

  - by insta

  Sample program below: using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace GenericsTest { class Program { static void Main(string[] args) { IRetrievable<int, User> repo = new FakeRepository(); Console.WriteLine(repo.Retrieve(35)); } } class User { public int Id { get; set; } public string Name { get; set; } } class FakeRepository : BaseRepository<User>, ICreatable<User>, IDeletable<User>, IRetrievable<int, User> { // why do I have to implement this here, instead of letting the // TKey generics implementation in the baseclass handle it? //public User Retrieve(int input) //{ // throw new NotImplementedException(); //} } class BaseRepository<TPoco> where TPoco : class,new() { public virtual TPoco Create() { return new TPoco(); } public virtual bool Delete(TPoco item) { return true; } public virtual TPoco Retrieve<TKey>(TKey input) { return null; } } interface ICreatable<TPoco> { TPoco Create(); } interface IDeletable<TPoco> { bool Delete(TPoco item); } interface IRetrievable<TKey, TPoco> { TPoco Retrieve(TKey input); } } This sample program represents the interfaces my actual program uses, and demonstrates the problem I'm having (commented out in FakeRepository). I would like for this method call to be generically handled by the base class (which in my real example is able to handle 95% of the cases given to it), allowing for overrides in the child classes by specifying the type of TKey explicitly. It doesn't seem to matter what parameter constraints I use for the IRetrievable, I can never get the method call to fall through to the base class. Also, if anyone can see an alternate way to implement this kind of behavior and get the result I'm ultimately looking for, I would be very interested to see it. Thoughts?

  Read the article

• Web UI element to represent two different micro-views of data in the same spot?

  - by Chris McCall

  I've been tasked with laying out a portion of a screen for a customer care (call center) app that serves as sort of a header/summary block at the top of the screen. Here's what it looks like: The important part is in the red box. That little tooltip is the biz's vision for how to represent both the numeric SiteId and the textual Site Name all in the same piece of screen real estate. I asked, and the business thinks the Name is more important than the ID, but lists the Id by default, because the Name can't be truncated in the display, and there's only so much horizontal room to put the data. So they go with the Id, because it's fewer characters, and then they have the user mouse-over the Id to display the name (presumably because the tooltip can be of unlimited width and since it's floating over the rest of the screen, the full name will always be displayed. So, here's my question: Is there some better UI metaphor that I don't know about that could get this job done, while meeting the following constraints?: Does not require the mouse (uses a keyboard shortcut to do the "reveal") Allows the user to copy and paste the name Will not truncate the name Provides for the display of both the ID and name in the same spot Works with IE7

  Read the article

• Does IE6 Really not Allow Me to set width/height from left/right/top/bottom???

  - by viatropos

  Building a site super quick and having it work on all my Mac browsers, I thought I'd take a gander on a friends old dell laptop with Windows XP and IE6. Nothing looks remotely correct. It's because I used lots of left/right/top/bottom (constraint) declarations to size elements proportionally to their parent's size (I didn't use percent sizes because the percents refer to the parent's size before margins and padding are applied, left/right/top/bottom refer to them after with position:absolute. I'm asking about that here :)). I've read lots these past few weeks on how horrible IE6 (and IE) is in general, but because of all the reasons people say to support it (large market share and the fear of installing better software), and because half the people in the company we're building a site for use IE6 (getting them to upgrade to Chrome slowly but surely), I thought if I could just get IE6 to render my constraints, that might help. So I am messing around with simple layouts here, and they work fine in my latest versions of Firefox, Safari, Chrome, and Opera, but IE6 is basically saying: If you haven't set a width or height on me, I'm assuming it's zero. But position:absolute; left:0px; right:0px; top:0px; bottom:0px; on a container that's width:1000px; height:1000px; should be the same as setting width:1000px; height:1000px on the child, no? Taking a quick look at the source for this, why won't IE6 render the constraint based absolutely positioned AND SIZED elements? (note: I will be messing around with that file for a while) Thanks

  Read the article

< Previous Page | 58 59 60 61 62 63 64 65 66 67 68 69  | Next Page >