Search Results

Search found 4993 results on 200 pages for 'conversion operator'.

Page 171/200 | < Previous Page | 167 168 169 170 171 172 173 174 175 176 177 178  | Next Page >

• How do I best remove the unicode characters that XHTML regards as non-valid using php?

  - by Andrew Stacey

  I run a forum designed to support an international mathematics group. I've recently switched it to unicode for better support of international characters. In debugging this conversion, I've discovered that not all unicode characters are considered as valid XHTML (the relevant website appears to be http://www.w3.org/TR/unicode-xml/). One of the steps that the forum software goes through before presenting the posts to the browser is an XHTML validation/sanitisation step. It seems a reasonable idea that at that stage it should remove any unicode characters that XHTML doesn't like. So my question is: Is there a standard (or best) way of doing this in PHP? (The forum is written in PHP, by the way.) I guess that the failsafe would be a simple str_replace (if that's also the best, do I need to do anything extra to make sure it works properly with unicode?) but that would involve me having to go through the XHTML DTD (or the above-referenced W3 page) carefully to figure out what characters to list in the search part of str_replace, so if this is the best way, has someone already done that so that I can steal, err, copy, it? (Incidentally, the character that caused the problem was U+000C, the 'formfeed', which (according to the W3 page) is valid HTML but invalid XHTML!)

  Read the article

• Update a PDF to include an encrypted, hidden, unique identifier?

  - by Dave Jarvis

  Background The idea is this: Person provides contact information for online book purchase Book, as a PDF, is marked with a unique hash Person downloads book PDF passwords are annoying and extremely easy to circumvent. The ideal process would be something like: Generate hash based on contact information Store contact information and hash in database Acquire book lock Update an "include" file with hash text Generate book as PDF (using pdflatex) Apply hash to book Release book lock Send email with book download link Technologies The following technologies can be used (other programming languages are possible, but libraries will likely be limited to those supplied by the host): C, Java, PHP LaTeX files PDF files Linux Question What programming techniques (or open source software) should I investigate to: Embed a unique hash (or other mark) to a PDF Create a collusion-attack resistant mark Develop a non-fragile (e.g., PDF -> EPS -> PDF still contains the mark) solution Research I have looked at the following possibilities: Steganography Natural Language Processing (NLP) Convert blank pages in PDF to images; mark those images; reassemble PDF LaTeX watermark package ImageMagick Steganograhy requires keeping a master copy of the images, and I'm not sure if the watermark would survive PDF -> EPS -> PDF, or other types of conversion. LaTeX creates an image cache, so any steganographic process would have to intercept that process somehow. NLP introduces grammatical errors. Inserting blank pages as images is immediately suspect; it is easy to replace suspicious blank pages. The LaTeX watermark package draws visible marks. ImageMagick draws visible marks. What other solutions are possible? Related Links http://www.tcpdf.org/ invisible watermarks in images Thank you!

  Read the article

• Copy whole SQL Server database into JSON from Python

  - by Oli

  I facing an atypical conversion problem. About a decade ago I coded up a large site in ASP. Over the years this turned into ASP.NET but kept the same database. I've just re-done the site in Django and I've copied all the core data but before I cancel my account with the host, I need to make sure I've got a long-term backup of the data so if it turns out I'm missing something, I can copy it from a local copy. To complicate matters, I no longer have Windows. I moved to Ubuntu on all my machines some time back. I could ask the host to send me a backup but having no access to a machine with MSSQL, I wouldn't be able to use that if I needed to. So I'm looking for something that does: db = {} for table in database: db[table.name] = [row for row in table] And then I could serialize db off somewhere for later consumption... But how do I do the table iteration? Is there an easier way to do all of this? Can MSSQL do a cross-platform SQLDump (inc data)? For previous MSSQL I've used pymssql but I don't know how to iterate the tables and copy rows (ideally with column headers so I can tell what the data is). I'm not looking for much code but I need a poke in the right direction.

  Read the article

• al32utf8 in oracle and SQL Server and DB2 pulling data

  - by Bob

  I have a non-utf8 oracle database running on 11.1.0.7. We need to support greek characters. So we have two options: use nvarchar, nclob fields for those fields that need greek (it is not all fields). We have tested this and gotten it to work with java coding. convert Oracle to AL32UTF8 database. I am not asking how to do this. I got this from the Oracle Site/Oracle Support. I know what is involved, lossy data, etc, increasing the size of the database. My question is we have users to our system that connect to our database with database links but work on SQL Server and IBM DB2 databases. I do not have access to those databases and I do not have experience with them. If they are not in UTF-8 databases what happens when they pull UTF8 data? I would assume that English/Ascii characters are fine and the greek will end up as junk data. I also ran Oracle Character set scanner (oracle command line utility you use to get info about the affects of a character set conversion). It says that my database will crease in sizez by about 20%. Does this have an affect on users with 3rd party databases? These are customers of our data and there is a limit to how much access I can have to them to run tests. Any information you have would be welcome.

  Read the article

• Polymorphic Numerics on .Net and In C#

  - by Bent Rasmussen

  It's a real shame that in .Net there is no polymorphism for numbers, i.e. no INumeric interface that unifies the different kinds of numerical types such as bool, byte, uint, int, etc. In the extreme one would like a complete package of abstract algebra types. Joe Duffy has an article about the issue: http://www.bluebytesoftware.com/blog/CommentView,guid,14b37ade-3110-4596-9d6e-bacdcd75baa8.aspx How would you express this in C#, in order to retrofit it, without having influence over .Net or C#? I have one idea that involves first defining one or more abstract types (interfaces such as INumeric - or more abstract than that) and then defining structs that implement these and wrap types such as int while providing operations that return the new type (e.g. Integer32 : INumeric; where addition would be defined as public Integer32 Add(Integer32 other) { return Return(Value + other.Value); } I am somewhat afraid of the execution speed of this code but at least it is abstract. No operator overloading goodness... Any other ideas? .Net doesn't look like a viable long-term platform if it cannot have this kind of abstraction I think - and be efficient about it. Abstraction is reuse.

  Read the article

• LINQ query code for complex merging of data.

  - by Stacey

  I've posted this before, but I worded it poorly. I'm trying again with a more well thought out structure. Re-writing this a bit to make it more clear. I have the following code and I am trying to figure out the shorter linq expression to do it 'inline'. Please examine the "Run()" method near the bottom. I am attempting to understand how to join two dictionaries together based on a matching identifier in one of the objects - so that I can use the query in this sort of syntax. var selected = from a in items.List() // etc. etc. select a; This is my class structure. The Run() method is what I am trying to simplify. I basically need to do this conversion inline in a couple of places, and I wanted to simplify it a great deal so that I can define it more 'cleanly'. class TModel { public Guid Id { get; set; } } class TModels : List<TModel> { } class TValue { } class TStorage { public Dictionary<Guid, TValue> Items { get; set; } } class TArranged { public Dictionary<TModel, TValue> Items { get; set; } } static class Repository { static public TItem Single<TItem, TCollection>(Predicate<TItem> expression) { return default(TItem); // access logic. } } class Sample { public void Run() { TStorage tStorage = new TStorage(); // access tStorage logic here. Dictionary<TModel, TValue> d = new Dictionary<TModel, TValue>(); foreach (KeyValuePair<Guid, TValue> kv in tStorage.Items) { d.Add(Repository.Single<TModel, TModels>(m => m.Id == kv.Key),kv.Value); } } }

  Read the article

• What is the 'page lifecycle' of an ASP.NET MVC page, compared to ASP.NET WebForms?

  - by Simon

  What is the 'page lifecycle' of an ASP.NET MVC page, compared to ASP.NET WebForms? I'm tryin to better understand this 'simple' question in order to determine whether or not existing pages I have in a (very) simple site can be easily converted from ASP.NET WebForms. Either a 'conversion' of the process below, or an alternative lifecycle would be what I'm looking for. What I'm currently doing: (yes i know that anyone capable of answering my question already knows all this -- i'm just tryin to get a comparison of the 'lifecycle' so i thought i'd start by filling in what we already all know) Rendering the page: I have a master page which contains my basic template I have content pages that give me named regions from the master page into which I put content. In an event handler for each content page I load data from the database (mostly read-only). I bind this data to ASP.NET controls representing grids, dropdowns or repeaters. This data all 'lives' inside the HTML generated. Some of it gets into ViewState (but I wont go into that too much!) I set properties or bind data to certain items like Image or TextBox controls on the page. The page gets sent to the client rendered as non-reusable HTML. I try to avoid using ViewState other than what the page needs as a minimum. Client side (not using ASP.NET AJAX): I may use JQuery and some nasty tricks to find controls on the page and perform operations on them. If the user selects from a dropdown -- a postback is generated which triggers a C# event in my codebehind. This event may go to the database, but whatever it does a completely newly generated HTML page ends up getting sent back to the client. I may use Page.Session to store key value pairs I need to reuse later So with MVC how does this 'lifecycle' change?

  Read the article

• strange redefined symbols

  - by Chris H

  I included this header into one of my own: http://codepad.org/lgJ6KM6b When I compiled I started getting errors like this: CMakeFiles/bin.dir/SoundProjection.cc.o: In function `Gnuplot::reset_plot()': /usr/lib/gcc/x86_64-pc-linux-gnu/4.3.4/include/g++-v4/new:105: multiple definition of `Gnuplot::reset_plot()' CMakeFiles/bin.dir/main.cc.o:project/gnuplot-cpp/gnuplot_i.hpp:962: first defined here CMakeFiles/bin.dir/SoundProjection.cc.o: In function `Gnuplot::set_smooth(std::basic_string, std::allocator const&)': project/gnuplot-cpp/gnuplot_i.hpp:1041: multiple definition of `Gnuplot::set_smooth(std::basic_string, std::allocator const&)' CMakeFiles/bin.dir/main.cc.o:project/gnuplot-cpp/gnuplot_i.hpp:1041: first defined here CMakeFiles/bin.dir/SoundProjection.cc.o:/usr/include/eigen2/Eigen/src/Core/arch/SSE/PacketMath.h:41: multiple definition of `Gnuplot::m_sGNUPlotFileName' I know it's hard to see in this mess, but look at where the redefinitions are taking place. They take place in files like /usr/lib/gcc/x86_64-pc-linux-gnu/4.3.4/include/g++-v4/new:105. How is the new operator getting information about a gnuplot header? I can't even edit that file. How could that ever even be possible? I'm not even sure how to start debugging this. I hope I've provided enough information. I wasn't able to reproduce this in a small project. I mostly just looking for tips on how to find out why this is happening, and how to track it down. Thanks.

  Read the article

• Applet to Object tags

  - by Andy

  im trying to get from applet to object so i can resolve z-index issues. The first applet tag works...my conversion to object doesn't. Can anyone point me in the right direction? From: <applet name='previewersGraph' codebase="http://www.mydomain.info/sub/" archive="TMApplets.jar" code='info.tm.web.applet.PreviewerStatsGraphApplet' width='446' height='291'> <param name="background-color" value="#ffffff" /> <param name="border-color" value="#8c8cad" /> To: <OBJECT id="previewersGraph" name="previewersGraph" classid="clsid:CAFEEFAC-0014-0002-0000-ABCDEFFEDCBA" width="200" height="200" align="baseline" codebase="http://java.sun.com/products/plugin/autodl/jinstall-1_4_2-windows-i586.cab#Version=1,4,2,0"> <PARAM name="code" value="info.tm.web.applet.PreviewerStatsGraphApplet"> <PARAM name="codebase" value="http://www.mydomain.info/sub/"> <PARAM name="type" value="application/x-java-applet;jpi-version=1.4.2"> <PARAM name="archive" value="TMApplets.jar"> <PARAM name="scriptable" value="true"> No Java 2 SDK, Standard Edition v 1.4.2 support for APPLET!! </OBJECT>

  Read the article

• Boost class/struct serialization to byte array

  - by Dave18

  does boost library provide functions to pack the class/struct data into a byte array to shorten the length of serialized data? Currently i'm using stringstream to get the serialized data, for example - struct data { std::string s1; std::string s2; int i; }; template <typename Archive> void serialize(Archive &ar, data &d, const unsigned int version) { ar & d.s1; ar & d.s2; ar & d.i; } int main() { data d; d.s1 = "This is my first string"; d.s2 = "This is my second string"; d.i = 10000; std::stringstream archive_stream; boost::archive::text_oarchive archive(archive_stream); archive.operator <<(d); } How would i use a byte array instead of stringstream for data?

  Read the article

• Sharing session variables from http and https versio

  - by tangurena

  I am trying to fix an ASP.NET site that a friend had botched converting from older technologies. To the user, the site appears to have public and secured sections. Behind the scenes, the public and private sites are separate web applications with separate app pools. The difficulty arises because it appears that the applications share the same session IDs (when going from the public to the secured pages, the session ID remains the same), yet none of the (InProc) session variables are getting passed from the public site to the private one. Basically, the workflow consists of the user checking a checkbox ("I agree" type of stuff) on the public site (let's call that page http://www.boring.gov/iAgree.aspx), then logging in on the secured site (let's call that page https://www.boring.gov/login.aspx). The commandments from the parent agency in DC are that the user may not bookmark the login page, the user has to click "I agree" every time they log in, and that the "I agree" stuff has to be on a separate page. What am I missing? How would you do it? Notes: 1 - This is getting hosted on a single Windows 2003 server. 2 - Yes, it is a government agency. 3 - I would have done things very differently if I was doing the conversion, but I wasn't brought in until the poop hit the fan, and it is too late to redo things. 4 - Two previous SO threads that appear to be related, yet don't apply are this and that

  Read the article

• rpy2: Converting a data.frame to a numpy array

  - by Mike Dewar

  I have a data.frame in R. It contains a lot of data : gene expression levels from many (125) arrays. I'd like the data in Python, due mostly to my incompetence in R and the fact that this was supposed to be a 30 minute job. I would like the following code to work. To understand this code, know that the variable path contains the full path to my data set which, when loaded, gives me a variable called immgen. Know that immgen is an object (a Bioconductor ExpressionSet object) and that exprs(immgen) returns a data frame with 125 columns (experiments) and tens of thousands of rows (named genes). robjects.r("load('%s')"%path) # loads immgen e = robjects.r['data.frame']("exprs(immgen)") expression_data = np.array(e) This code runs, but expression_data is simply array([[1]]). I'm pretty sure that e doesn't represent the data frame generated by exprs() due to things like: In [40]: e._get_ncol() Out[40]: 1 In [41]: e._get_nrow() Out[41]: 1 But then again who knows? Even if e did represent my data.frame, that it doesn't convert straight to an array would be fair enough - a data frame has more in it than an array (rownames and colnames) and so maybe life shouldn't be this easy. However I still can't work out how to perform the conversion. The documentation is a bit too terse for me, though my limited understanding of the headings in the docs implies that this should be possible. Anyone any thoughts?

  Read the article

• SFINAE failing with enum template parameter

  - by zeroes00

  Can someone explain the following behaviour (I'm using Visual Studio 2010). header: #pragma once #include <boost\utility\enable_if.hpp> using boost::enable_if_c; enum WeekDay {MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY}; template<WeekDay DAY> typename enable_if_c< DAY==SUNDAY, bool >::type goToWork() {return false;} template<WeekDay DAY> typename enable_if_c< DAY!=SUNDAY, bool >::type goToWork() {return true;} source: bool b = goToWork<MONDAY>(); compiler this gives error C2770: invalid explicit template argument(s) for 'enable_if_c<DAY!=6,bool>::type goToWork(void)' and error C2770: invalid explicit template argument(s) for 'enable_if_c<DAY==6,bool>::type goToWork(void)' But if I change the function template parameter from the enum type WeekDay to int, it compiles fine: template<int DAY> typename enable_if_c< DAY==SUNDAY, bool >::type goToWork() {return false;} template<int DAY> typename enable_if_c< DAY!=SUNDAY, bool >::type goToWork() {return true;} Also the normal function template specialization works fine, no surprises there: template<WeekDay DAY> bool goToWork() {return true;} template<> bool goToWork<SUNDAY>() {return false;} To make things even weirder, if I change the source file to use any other WeekDay than MONDAY or TUESDAY, i.e. bool b = goToWork<THURSDAY>(); the error changes to this: error C2440: 'specialization' : cannot convert from 'int' to 'const WeekDay' Conversion to enumeration type requires an explicit cast (static_cast, C-style cast or function-style cast)

  Read the article

• Update mapping table in Linq

  - by Gary McGill

  I have a table Customers with a CustomerId field, and a table of Publications with a PublicationId field. Finally, I have a mapping table CustomersPublications that records which publications a customer can access - it has two fields: CustomerId field PublicationId. For a given customer, I want to update the CustomersPublications table based on a list of publication ids. I want to remove records in CustomersPublications where the PublicationId is not in the list, and add new records where the PublicationId is in the list but not already in the table. This would be easy in SQL, but I can't figure out how to do it in Linq. For the delete part, I tried: var recordsToDelete = dataContext.CustomersPublications.Where ( cp => (cp.CustomerId == customerId) && ! publicationIds.Contains(cp.PublicationId) ); dataContext.CustomersPublications.DeleteAllOnSubmit(recordsToDelete); ... but that didn't work. I got an error: System.NotSupportedException: Method 'Boolean Contains(Int32)' has no supported translation to SQL So, I tried using Any(), as follows: var recordsToDelete = dataContext.CustomersPublications.Where ( cp => (cp.CustomerId == customerId) && ! publicationIds.Any(p => p == cp.PublicationId) ); ... and this just gives me another error: System.NotSupportedException: Local sequence cannot be used in LINQ to SQL implementation of query operators except the Contains() operator Any pointers? [I have to say, I find Linq baffling (and frustrating) for all but the simplest queries. Better error messages would help!]

  Read the article

• Can I use a property placeholder with Spring EL?

  - by David Easley

  Before upgrading to Spring 3 I had this in my applicationContext.xml file: <bean class="com.northgateis.pole.ws.PolePayloadValidatingInterceptor"> <property name="validateRequest" value="${validateRequest}" /> <property name="validateResponse" value="${validateResponse}" /> </bean> where ${validateRequest) and ${validateRequest) refer to properties that may or may not be defined in my properties file. In Spring 2, if these proeprties were not present in the properties file the setters on the bean were not called and so the defaults hard-coded in PolePayloadValidatingInterceptor were used. After upgrading to Spring 3, it seems the behaviour is different: If the properties are not present in the properties file I get the following exception: SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener org.springframework.beans.factory.BeanDefinitionStoreException: Invalid bean definition with name 'annotationMapping' defined in class path resource [com/northgateis/pole/ws/applicationContext-ws.xml]: Could not resolve placeholder 'validateRequest' at org.springframework.beans.factory.config.PropertyPlaceholderConfigurer.processProperties(PropertyPlaceholderConfigurer.java:272) at org.springframework.beans.factory.config.PropertyResourceConfigurer.postProcessBeanFactory(PropertyResourceConfigurer.java:75) at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:640) at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:615) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:405) at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:272) I tried dabbling with Spring EL but the following doesn't seem to work: <bean class="com.northgateis.pole.ws.PolePayloadValidatingInterceptor"> <property name="validateRequest" value="${validateRequest?:true}" /> <property name="validateResponse" value="${validateResponse?:false}" /> </bean> The value after the Elvis operator is always used, even when the properties are defined in the proeprties file. Interesting that the syntax is accepted. Any suggestions?

  Read the article

• Using libcurl to create a valid POST

  - by Haraldo

  static int get( const char * cURL, const char * cParam ) { CURL *handle; CURLcode result; std::string buffer; char errorBuffer[CURL_ERROR_SIZE]; //struct curl_slist *headers = NULL; //headers = curl_slist_append(headers, "Content-Type: Multipart/Related"); //headers = curl_slist_append(headers, "type: text/xml"); // Create our curl handle handle = curl_easy_init(); if( handle ) { curl_easy_setopt(handle, CURLOPT_ERRORBUFFER, errorBuffer); //curl_easy_setopt(handle, CURLOPT_HEADER, 0); //curl_easy_setopt(handle, CURLOPT_HTTPHEADER, headers); curl_easy_setopt(handle, CURLOPT_POST, 1); curl_easy_setopt(handle, CURLOPT_POSTFIELDS, cParam); curl_easy_setopt(handle, CURLOPT_POSTFIELDSIZE, strlen(cParam)); curl_easy_setopt(handle, CURLOPT_FOLLOWLOCATION, 1); curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, Request::writer); curl_easy_setopt(handle, CURLOPT_WRITEDATA, &buffer); curl_easy_setopt(handle, CURLOPT_USERAGENT, "libcurl-agent/1.0"); curl_easy_setopt(handle, CURLOPT_URL, cURL); result = curl_easy_perform(handle); curl_easy_cleanup(handle); } if( result == CURLE_OK ) { return atoi( buffer.c_str() ); } return 0; } Hi there, first of all I'm having trouble debugging this in visual studio express 2008 so I'm unsure what buffer.c_str() might actually be returning but I am outputting 1 or 0 to the web page being posted to. Therefore I'm expecting the buffer to be one or the other, however I seem to only be returning 0 or equivalent. Does the code above look like it will return what I expect or should my variable types be different? The conversion using "atoi" may be an issue. Any thought would be much appreciated.

  Read the article

• Convert pre-IEEE-574 C++ floating-point numbers to/from C#

  - by Richard Kucia

  Before .Net, before math coprocessors, before IEEE-574, Microsoft defined a bit pattern for floating-point numbers. Old versions of the C++ compiler happily used that definition. I am writing a C# app that needs to read/write such floating-point numbers in a file. How can I do the conversions between the 2 bit formats? I need conversion methods in both directions. This app is going to run in a PocketPC/WinCE environment. Changing the structure of the file is out-of-scope for this project. Is there a C++ compiler option that instructs it to use the old FP format? That would be ideal. I could then exchange data between the C# code and C++ code by using a null-terminated text string, and the C++ methods would be simple wrappers around sprintf and atof functions. At the very least, I'm hoping someone can reply with the bit definitions for the old FP format, so I can put together a low-level bit manipulation algorithm if necessary. Thanks.

  Read the article

• Parsing JSON to XML using net.sf.json (java)

  - by Castanho

  Hi guys, I'm parsing a generic JSON to a XML using net.sf.json. (I'm not using POJO Obj in the conversion) When dealing with vectors I'm receiving: <root> <entry> <Id>1</accountId> <Items> <e> <cost>0.1</cost> <debit>0.1</debit> </e> <e> <cost>0.1</cost> <debit>0.1</debit> </e> </Items> </entry> </root> When the correct for my point of view should be: <root> <entry> <accountId>1</accountId> <Items> <cost>0.1</cost> <debit>0.1</debit> </Items> <Items> <cost>0.2</cost> <debit>0.2</debit> </Items> </entry> </root> Do anyone have used this lib and could help me? Any tips could help! Thanks in advance

  Read the article

• Triangle numbers problem....show within 4 seconds

  - by Daredevil

  The sequence of triangle numbers is generated by adding the natural numbers. So the 7th triangle number would be 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28. The first ten terms would be: 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ... Let us list the factors of the first seven triangle numbers: 1: 1 3: 1,3 6: 1,2,3,6 10: 1,2,5,10 15: 1,3,5,15 21: 1,3,7,21 28: 1,2,4,7,14,28 We can see that 28 is the first triangle number to have over five divisors. Given an integer n, display the first triangle number having at least n divisors. Sample Input: 5 Output 28 Input Constraints: 1<=n<=320 I was obviously able to do this question, but I used a naive algorithm: Get n. Find triangle numbers and check their number of factors using the mod operator. But the challenge was to show the output within 4 seconds of input. On high inputs like 190 and above it took almost 15-16 seconds. Then I tried to put the triangle numbers and their number of factors in a 2d array first and then get the input from the user and search the array. But somehow I couldn't do it: I got a lot of processor faults. Please try doing it with this method and paste the code. Or if there are any better ways, please tell me.

  Read the article

• Simple way to repeat a String in java

  - by e5

  I'm looking for a simple commons method or operator that allows me to repeat some String n times. I know I could write this using a for loop, but I wish to avoid for loops whenever necessary and a simple direct method should exist somewhere. String str = "abc"; String repeated = str.repeat(3); repeated.equals("abcabcabc"); Related to: repeat string javascript Create NSString by repeating another string a given number of times Edited I try to avoid for loops when they are not completely necessary because: They add to the number of lines of code even if they are tucked away in another function. Someone reading my code has to figure out what I am doing in that for loop. Even if it is commented and has meaningful variables names, they still have to make sure it is not doing anything "clever". Programmers love to put clever things in for loops, even if I write it to "only do what it is intended to do", that does not preclude someone coming along and adding some additional clever "fix". They are very often easy to get wrong. For loops that involving indexes tend to generate off by one bugs. For loops often reuse the same variables, increasing the chance of really hard to find scoping bugs. For loops increase the number of places a bug hunter has to look.

  Read the article

• How do I tell gcc to relax its restrictions on typecasting when calling a C function from C++?

  - by Daryl Spitzer

  I'm trying to use Cmockery to mock C functions called from C++ code. Because the SUT is in C++, my tests need to be in C++. When I use the Cmockery expect_string() macro like this: expect_string(mock_function, url, "Foo"); I get: my_tests.cpp: In function ‘void test_some_stuff(void**)’: my_tests.cpp:72: error: invalid conversion from ‘void*’ to ‘const char*’ my_tests.cpp:72: error: initializing argument 5 of ‘void _expect_string(const char*, const char*, const char*, int, const char*, int)’ I see in cmockery.h that expect_string is defined: #define expect_string(function, parameter, string) \ expect_string_count(function, parameter, string, 1) #define expect_string_count(function, parameter, string, count) \ _expect_string(#function, #parameter, __FILE__, __LINE__, (void*)string, \ count) And here's the prototype for _expect_string (from cmockery.h): void _expect_string( const char* const function, const char* const parameter, const char* const file, const int line, const char* string, const int count); I believe the problem is that I'm compiling C code as C++, so the C++ compiler is objecting to (void*)string in the expect_string_count macro being passed as the const char* string parameter to the _expect_string() function. I've already used extern "C" around the cmockery.h include in my_tests.cpp like this: extern "C" { #include <cmockery.h> } ...in order to get around name-mangling problems. (See "How do I compile and link C++ code with compiled C code?") Is there a command-line option or some other means of telling g++ how to relax its restrictions on typecasting from my test's C++ code to the C function in cmockery.c? This is the command I'm currently using to build my_tests.cpp: g++ -m32 -I ../cmockery-0.1.2 -c my_tests.cpp -o $(obj_dir)/my_tests.o

  Read the article

• C++ stack for multiple data types (RPN vector calculator)

  - by Arrieta

  Hello: I have designed a quick and basic vector arithmetic library in C++. I call the program from the command line when I need a rapid cross product, or angle between vectors. I don't use Matlab or Octave or related, because the startup time is larger than the computation time. Again, this is for very basic operations. I am extending this program, and I will make it work as an RPN calculator, for operations of the type: 1 2 3 4 5 6 x out: -3 6 -3 (give one vector, another vector, and the "cross" operator; spit out the cross product) The stack must accept 3d vectors or scalars, for operations like: 1 2 3 2 * out: 2 4 6 The lexer and parser for this mini-calculator are trivial, but I cannot seem to think of a good way for creating the internal stack. How would you create a stack of for containing vectors or doubles (I rolled up my own very simple vector class - less than one hundred lines and it does everything I need). How can I create a simple stack which accepts elements of class Vector or type double? Thank you.

  Read the article

• Python: Best way to check for Python version in program that uses new language features?

  - by Mark Harrison

  If I have a python script that requires at least a particular version of python, what is the correct way to fail gracefully when an earlier version of python is used to launch the script? How do I get control early enough to issue an error message and exit? For example, I have a program that uses the ternery operator (new in 2.5) and "with" blocks (new in 2.6). I wrote a simple little interpreter-version checker routine which is the first thing the script would call ... except it doesn't get that far. Instead, the script fails during python compilation, before my routines are even called. Thus the user of the script sees some very obscure synax error tracebacks - which pretty much require an expert to deduce that it is simply the case of running the wrong version of python. update I know how to check the version of python. The issue is that some syntax is illegal in older versions of python. Consider this program: import sys if sys.version_info < (2, 4): raise "must use python 2.5 or greater" else: # syntax error in 2.4, ok in 2.5 x = 1 if True else 2 print x When run under 2.4, I want this result $ ~/bin/python2.4 tern.py must use python2.5 or greater and not this result: $ ~/bin/python2.4 tern.py File "tern.py", line 5 x = 1 if True else 2 ^ SyntaxError: invalid syntax (channeling for a coworker)

  Read the article

• What is the most efficient way to display decoded video frames in Qt?

  - by Jason

  What is the fastest way to display images to a Qt widget? I have decoded the video using libavformat and libavcodec, so I already have raw RGB or YCbCr 4:2:0 frames. I am currently using a QGraphicsView with a QGraphicsScene object containing a QGraphicsPixmapItem. I am currently getting the frame data into a QPixmap by using the QImage constructor from a memory buffer and converting it to QPixmap using QPixmap::fromImage(). I like the results of this and it seems relatively fast, but I can't help but think that there must be a more efficient way. I've also heard that the QImage to QPixmap conversion is expensive. I have implemented a solution that uses an SDL overlay on a widget, but I'd like to stay with just Qt since I am able to easily capture clicks and other user interaction with the video display using the QGraphicsView. I am doing any required video scaling or colorspace conversions with libswscale so I would just like to know if anyone has a more efficient way to display the image data after all processing has been performed. Thanks.

  Read the article

• Unable to run .exe application using C# code

  - by bjh Hans

  I have an exe that i need to call from my C# Program with two arguments(PracticeId,ClaimId) for example Suppose if i have an application "test.exe" , whose functionality is to make claim acording to given two argument On cmd i would normally give the following command as: test.exe 1 2 and it works fine and performs its job of conversion. but what if i want to execute the same thing using my c# code. i am using the following sample code: Process compiler = new Process(); compiler.StartInfo.FileName = "test.exe" ; compiler.StartInfo.Arguments = "1 2" ; compiler.StartInfo.UseShellExecute = true; compiler.StartInfo.RedirectStandardOutput = true; compiler.Start(); when i try to invoke the test.exe using the above code , it fails to perform its operation of making claim txt file what is the issue in this i don' know pls help me regarding this whether the problem of threding or not i don't know. Can anyone tell me if i need to add anything more to the above code It would be great if somebody could provide some help on the above topic.

  Read the article

< Previous Page | 167 168 169 170 171 172 173 174 175 176 177 178  | Next Page >