Search Results

Search found 36715 results on 1469 pages for 'boost string'.

Page 106/1469 | < Previous Page | 102 103 104 105 106 107 108 109 110 111 112 113  | Next Page >

  • c# string interning

    - by CodingThunder
    I am trying to understand string interning and why is doesn't seem to work in my example. The point of the example is to show Example 1 uses less (a lot less memory) as it should only have 10 strings in memory. However, in the code below both example use roughly the same amount of memory (virtual size and working set). Please advice why example 1 isn't using a lot less memory? Thanks Example 1: IList<string> list = new List<string>(10000); for (int i = 0; i < 10000; i++) { for (int k = 0; k < 10; k++) { list.Add(string.Intern(k.ToString())); } } Console.WriteLine("intern Done"); Console.ReadLine(); Example 2: IList<string> list = new List<string>(10000); for (int i = 0; i < 10000; i++) { for (int k = 0; k < 10; k++) { list.Add(k.ToString()); } } Console.WriteLine("intern Done"); Console.ReadLine();

    Read the article

  • Tool to detect use/abuse of String.Concat (where StringBuilder should be used)

    - by Mark Rushakoff
    It's common knowledge that you shouldn't use a StringBuilder in place of a small number of concatenations: string s = "Hello"; if (greetingWorld) { s += " World"; } s += "!"; However, in loops of a significant size, StringBuilder is the obvious choice: string s = ""; foreach (var i in Enumerable.Range(1,5000)) { s += i.ToString(); } Console.WriteLine(s); Is there a tool that I can run on either raw C# source or a compiled assembly to identify where in the source code that String.Concat is being called? (If you're not familiar, s += "foo" is mapped to String.Concat in the IL output.) Obviously, I can't realistically search through an entire project and evaluate every += to identify whether the lvalue is a string. Ideally, it would only point out calls inside a for/foreach loop, but I would even put up with all the false positives of noting every String.Concat. Also, I'm aware that there are some refactoring tools that will automatically refactor my code to use StringBuilder, but I am only interested in identifying the Concat usage at this point. I routinely run Gendarme and FxCop on my code, and neither of those tools identify what I've described.

    Read the article

  • Serializable object in intent returning as String

    - by B_
    In my application, I am trying to pass a serializable object through an intent to another activity. The intent is not entirely created by me, it is created and passed through a search suggestion. In the content provider for the search suggestion, the object is created and placed in the SUGGEST_COLUMN_INTENT_EXTRA_DATA column of the MatrixCursor. However, when in the receiving activity I call getIntent().getSerializableExtra(SearchManager.EXTRA_DATA_KEY), the returned object is of type String and I cannot cast it into the original object class. I tried making a parcelable wrapper for my object that calls out.writeSerializable(...) and use that instead but the same thing happened. The string that is returned is like a generic Object toString(), i.e. com.foo.yak.MyAwesomeClass@4350058, so I'm assuming that toString() is being called somewhere where I have no control. Hopefully I'm just missing something simple. Thanks for the help! Edit: Some of my code This is in the content provider that acts as the search authority: //These are the search suggestion columns private static final String[] COLUMNS = { "_id", // mandatory column SearchManager.SUGGEST_COLUMN_TEXT_1, SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA }; //This places the serializable or parcelable object (and other info) into the search suggestion private Cursor getSuggestions(String query, String[] projection) { List<Widget> widgets = WidgetLoader.getMatches(query); MatrixCursor cursor = new MatrixCursor(COLUMNS); for (Widget w : widgets) { cursor.addRow(new Object[] { w.id w.name w.data //This is the MyAwesomeClass object I'm trying to pass }); } return cursor; } This is in the activity that receives the search suggestion: public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Object extra = getIntent().getSerializableExtra(SearchManager.EXTRA_DATA_KEY); //extra.getClass() returns String, when it should return MyAwesomeClass, so this next line throws a ClassCastException and causes a crash MyAwesomeClass mac = (MyAwesomeClass)extra; ... }

    Read the article

  • <string xmlns=''> was not expected in c#

    - by Nishant
    Hi all I am trying to serialize value in xml. Every time I am getting <string xmlns=''> was not expected in c# Not able to find root cause plz help me out here. namespace CustomDataType.usercontrols { public partial class CustomDataTypes : System.Web.UI.UserControl, umbraco.editorControls.userControlGrapper.IUsercontrolDataEditor { private Status _umbval; public object value { get { var status = GetStatus(); return SerializationHelper.ValueToXmlString(status); } set { //if (value == null || string.IsNullOrEmpty(value.ToString())) //{ // _umbval = Status.Empty; //} //else //{ _umbval =(Status)SerializationHelper.ValueFromXmlString(value,typeof(Status)); //} } } } } using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Xml.Serialization; namespace CustomDataType { [Serializable] [XmlRoot("StatuMain")] public class Status { [XmlElement("statusvalue")] public string StatusValue { get; set; } [XmlElement("statusvalue1")] public string StatusValue1 { get; set; } [XmlElement("statusvalue2")] public string StatusValue2 { get; set; } [XmlElement("statusvalue3")] public string StatusValue3 { get; set; } //[XmlElement("isEmailChecked")] //public bool HasEmailChecked { get; set; } //[XmlElement("datetime")] //public DateTime Date { get; set; } public static Status Empty { get { var schedule = new Status(); schedule = null; return schedule; } } } }

    Read the article

  • Pick up relevant information from a string using regular expression C#3.0

    - by Newbie
    Hi, I have a situation. I have been given some file name which can be like <filename>YYYYMMDD<fileextension> some valid file names that will satisfy the above pattern are as under xxx20100326.xls, xxx2v20100326.csv, x_20100326.xls, xy2z_abc_20100326_xyz.csv, abc.xyz.20100326.doc, ab2.v.20100326.doc, abc.v.20100326_xyz.xls In what ever be the above defined case, I need to pick up the dates only. So for all the cases, the output will be 20100326. I am trying to achieve the same but no luck. Here is what I have done so far string testdata = "x2v20100326.csv"; string strYYYY = @"\d{4}"; string strMM = @"(1[0-2]|0[1-9])"; string strDD = @"(3[0-1]|[1-2][0-9]|0[1-9])"; string regExPattern = @"\A" + strYYYY + strMM + strDD + @"\Z"; Regex regex = new Regex(regExPattern); Match match = regex.Match(testdata); if (match.Success) { string result = match.Groups[0].Value; } I am using c#3.0 and dotnet framework 3.5 Please help. It is very urgent Thanks in advance.

    Read the article

  • PasswordFiled char[] to String in Java connection MySql?

    - by user1819551
    This is a jFrame to connect to the database and this is in the button connect. My issue is in the passwordField NetBeans make me do a char[], but my .getConnection not let me insert the char[] ERROR: "no suitable method found for getConnection(String,String,char[])". So I will change to String right? So when I change and run the jFrame said access denied. when I start doing the System.out.println(l) " Give me the right answer" Like this: "Alex". But when I do the System.out.println(password) "Give me the Array spaces and not the value" Like this: jdbc:mysql://localhost/home inventory root [C@5be5ab68 <--- Array space . What I doing wrong? try { Class.forName("org.gjt.mm.mysql.Driver"); //Load the driver String host = "jdbc:mysql://"+tServerHost.getText()+"/"+tSchema.getText(); String uName = tUsername.getText(); char[] l = pPassword.getPassword(); System.out.println(l); String password= l.toString(); System.out.println(host+uName+l); con = DriverManager.getConnection(host, uName, password); System.out.println(host+uName+password); } catch (SQLException | ClassNotFoundException ex) { JOptionPane.showMessageDialog(this, ex.getMessage()); } }

    Read the article

  • c# logic to get the first non-repeating(distinct) character from the string

    - by NoviceToDotNet
    In c# i want to create logic that if i a string like abcabda is passed to a method then it should return first non repeative character from string like in above it should return c. i am unable to convert a string to array of character then how to make comparison of each array character to the string and return the first non repeative character. CanI make it like this? class A { static void main() { A a=new A(); char ch=a.m1(abcabd); } } class B { char m1(string s) { string s1=s; char[] ch1=new char[s.length]; for(int x=0; x<s.length;x++) { ch1[x]=s[x]; } for(int x=0; x<s.length; x++) { for(int y=0; y<s.lenth; y++) { if(s[x]=ch1[y]) { /// here i am confused how to create logic for comparison please let me know // and how to return the character } } } } }

    Read the article

  • Postfix/ClamAV not stopping viruses under Virtualmin

    - by Josh
    I am using Virtualmin and have it set up to have Postfix scan incoming emails with ClamAV (using clamdscan) and delete any emails which contain a virus. However when I email myself the EICAR test string, it comes through just fine. I know ClamAV will report this file as a virus. How can I troubleshoot this / what could be wrong?

    Read the article

  • Using JAXB to unmarshal/marshal a List<String> - Inheritance

    - by gerry
    I've build the following case. An interface for all JAXBLists: public interface JaxbList<T> { public abstract List<T> getList(); } And an base implementation: @XmlRootElement(name="list") public class JaxbBaseList<T> implements JaxbList<T>{ protected List<T> list; public JaxbBaseList(){} public JaxbBaseList(List<T> list){ this.list=list; } @XmlElement(name="item" ) public List<T> getList(){ return list; } } As well as an implementation for a list of URIs: @XmlRootElement(name="uris") public class JaxbUriList2 extends JaxbBaseList<String> { public JaxbUriList2() { super(); } public JaxbUriList2(List<String> list){ super(list); } @Override @XmlElement(name="uri") public List<String> getList() { return list; } } And I'm using the List in the following way: public JaxbList<String> init(@QueryParam("amount") int amount){ List<String> entityList = new Vector<String>(); ... enityList.add("http://uri"); ... return new JaxbUriList2(entityList); } I thought the output should be: <uris> <uri> http://uri </uri> ... </uris> But it is something like this: <uris> <item xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs="http://www.w3.org/2001/XMLSchema" xsi:type="xs:string"> http://uri </item> ... <uri> http://uri </uri> ... </uris> I think it has something to do with the inheritance, but I don't get it... What's the problem? - How can I fix it? Thanks in advance!

    Read the article

  • How to dynamically expand a string in C

    - by sa125
    Hi - I have a function that recursively makes some calculations on a set of numbers. I want to also pretty-print the calculation in each recursion call by passing the string from the previous calculation and concatenating it with the current operation. A sample output might look like this: 3 (3) + 2 ((3) + 2) / 4 (((3) + 2) / 4) x 5 ((((3) + 2) / 4) x 5) + 14 ... and so on So basically, the second call gets 3 and appends + 2 to it, the third call gets passed (3) + 2 , etc. My recursive function prototype looks like this: void calc_rec(int input[], int length, char * previous_string); I wrote a 2 helper functions to help me with the operation, but they implode when I test them: /********************************************************************** * dynamically allocate and append new string to old string and return a pointer to it **********************************************************************/ char * strapp(char * old, char * new) { // find the size of the string to allocate int len = sizeof(char) * (strlen(old) + strlen(new)); // allocate a pointer to the new string char * out = (char*)malloc(len); // concat both strings and return sprintf(out, "%s%s", old, new); return out; } /********************************************************************** * returns a pretty math representation of the calculation op **********************************************************************/ char * mathop(char * old, char operand, int num) { char * output, *newout; char fstr[50]; // random guess.. couldn't think of a better way. sprintf(fstr, " %c %d", operand, num); output = strapp(old, fstr); newout = (char*)malloc( 2*sizeof(char)+sizeof(output) ); sprintf(newout, "(%s)", output); free(output); return newout; } void test_mathop() { int i, total = 10; char * first = "3"; printf("in test_mathop\n"); while (i < total) { first = mathop(first, "+", i); printf("%s\n", first); ++i; } } strapp() returns a pointer to newly appended strings (works), and mathop() is supposed to take the old calculation string ("(3)+2"), a char operand ('+', '-', etc) and an int, and return a pointer to the new string, for example "((3)+2)/3". Any idea where I'm messing things up? thanks.

    Read the article

  • SharedObject (Flex 3.2) behaving unexpectedly when query string present in URL

    - by rhtx
    Summary: The behavior detailed below seems to indicate that if your app at www.someplace.com sets/retrieves data via a SharedObject, there is some sort of .sol collision if the user hits your app at someplace.com, and then later at someplace.com?name=value. Can anyone confirm or refute this? I'm working on a Flex web app that presents the user with a login page. When the user has logged in, he/she is presented with a 'room' which is associated with a 'group'. We store the last-visited room/group combination in a SharedObject - so when a given user logs in, they are taken into the most recent room in which they were active. That works fine, but we also have an auto-login system which involves the user clicking on a link to the app url with a query string attached. There are two types of these links. 1) the query string includes username, groupId, and roomId 2) the query string includes only the username Because we are working fast and have only a few developers, the auto-login system is built on the last-vist system. During the auto-login process, the url is inspected and if groupId and roomId values are found in the query string, the SharedObject is opened and the last-visit group/room id values are overwritten by the param values. That works fine, also, when the app is hit with a query string of the second type (no groupId and roomId params), the app goes to the SharedObject to get the stored room and group id values, as it normally would. And here's the problem: The values it comes back with are whatever the last room/group param values were, not whatever the last last-visit room/group values are. And if the given user has never hit the app with query string that included group and room id values, the app gets null values from the SharedObject. It took some digging around, but what it looks like is happening is that a second set of data is being stored/expected in the SharedObject if a query string is present in the URL. Looking at the .sol file in a text editor I see more untranslated code, and additional group and room values, once I've hit the app with URLs that contain query strings. I'm not finding anything on the web about this, but that may just be due to a lack of necessary search skills. Has anyone else run into anything similar? Or do you know how to address this? I've tried setting Security.exactSettings to false, already - was really hoping that was going to work.

    Read the article

  • Is there a standard way to encode a .NET string into javascript string for use in MS AJAX?

    - by Rich Andrews
    I'm trying to pass the output of a SQL Server exception to the client using the RegisterStartUpScript method of the MS ScriptManager. This works fine for some errors but when the exception contains single quotes the alert fails. I dont want to only escape single quotes though - Is there a standard function i can call to escape any special chars for use in Javascript? string scriptstring = "alert('" + ex.Message + "');"; ScriptManager.RegisterStartupScript(this, this.GetType(), "Alert", scriptstring , true); Thanks tpeczek, the code almost worked for me :) but with a slight amendment (the escaping of single quotes) it works a treat. I've included my amended version here... public class JSEncode { /// <summary> /// Encodes a string to be represented as a string literal. The format /// is essentially a JSON string. /// /// The string returned includes outer quotes /// Example Output: "Hello \"Rick\"!\r\nRock on" /// </summary> /// <param name="s"></param> /// <returns></returns> public static string EncodeJsString(string s) { StringBuilder sb = new StringBuilder(); sb.Append("\""); foreach (char c in s) { switch (c) { case '\'': sb.Append("\\\'"); break; case '\"': sb.Append("\\\""); break; case '\\': sb.Append("\\\\"); break; case '\b': sb.Append("\\b"); break; case '\f': sb.Append("\\f"); break; case '\n': sb.Append("\\n"); break; case '\r': sb.Append("\\r"); break; case '\t': sb.Append("\\t"); break; default: int i = (int)c; if (i < 32 || i > 127) { sb.AppendFormat("\\u{0:X04}", i); } else { sb.Append(c); } break; } } sb.Append("\""); return sb.ToString(); } } As mentioned below - original source: here

    Read the article

  • Use WLST to Delete All JMS Messages From a Destination

    - by james.bayer
    I got a question today about whether WebLogic Server has any tools to delete all messages from a JMS Queue.  It just so happens that the WLS Console has this capability already.  It’s available on the screen after the “Show Messages” button is clicked on a destination’s Monitoring tab as seen in the screen shot below. The console is great for something ad-hoc, but what if I want to automate this?  Well it just so happens that the console is just a weblogic application layered on top of the JMX Management interface.  If you look at the MBean Reference, you’ll find a JMSDestinationRuntimeMBean that includes the operation deleteMessages that takes a JMS Message Selector as an argument.  If you pass an empty string, that is essentially a wild card that matches all messages. Coding a stand-alone JMX client for this is kind of lame, so let’s do something more suitable to scripting.  In addition to the console, WebLogic Scripting Tool (WLST) based on Jython is another way to browse and invoke MBeans, so an equivalent interactive shell session to delete messages from a destination would looks like this: D:\Oracle\fmw11gr1ps3\user_projects\domains\hotspot_domain\bin>setDomainEnv.cmd D:\Oracle\fmw11gr1ps3\user_projects\domains\hotspot_domain>java weblogic.WLST   Initializing WebLogic Scripting Tool (WLST) ...   Welcome to WebLogic Server Administration Scripting Shell   Type help() for help on available commands   wls:/offline> connect('weblogic','welcome1','t3://localhost:7001') Connecting to t3://localhost:7001 with userid weblogic ... Successfully connected to Admin Server 'AdminServer' that belongs to domain 'hotspot_domain'.   Warning: An insecure protocol was used to connect to the server. To ensure on-the-wire security, the SSL port or Admin port should be used instead.   wls:/hotspot_domain/serverConfig> serverRuntime() Location changed to serverRuntime tree. This is a read-only tree with ServerRuntimeMBean as the root. For more help, use help(serverRuntime)   wls:/hotspot_domain/serverRuntime> cd('JMSRuntime/AdminServer.jms/JMSServers/JMSServer-0/Destinations/SystemModule-0!Queue-0') wls:/hotspot_domain/serverRuntime/JMSRuntime/AdminServer.jms/JMSServers/JMSServer-0/Destinations/SystemModule-0!Queue-0> ls() dr-- DurableSubscribers   -r-- BytesCurrentCount 0 -r-- BytesHighCount 174620 -r-- BytesPendingCount 0 -r-- BytesReceivedCount 253548 -r-- BytesThresholdTime 0 -r-- ConsumersCurrentCount 0 -r-- ConsumersHighCount 0 -r-- ConsumersTotalCount 0 -r-- ConsumptionPaused false -r-- ConsumptionPausedState Consumption-Enabled -r-- DestinationInfo javax.management.openmbean.CompositeDataSupport(compositeType=javax.management.openmbean.CompositeType(name=DestinationInfo,items=((itemName=ApplicationName,itemType=javax.management.openmbean.SimpleType(name=java.lang.String)),(itemName=ModuleName,itemType=javax.management.openmbean.SimpleType(name=java.lang.String)),(itemName openmbean.SimpleType(name=java.lang.Boolean)),(itemName=SerializedDestination,itemType=javax.management.openmbean.SimpleType(name=java.lang.String)),(itemName=ServerName,itemType=javax.management.openmbean.SimpleType(name=java.lang.String)),(itemName=Topic,itemType=javax.management.openmbean.SimpleType(name=java.lang.Boolean)),(itemName=VersionNumber,itemType=javax.management.op ule-0!Queue-0, Queue=true, SerializedDestination=rO0ABXNyACN3ZWJsb2dpYy5qbXMuY29tbW9uLkRlc3RpbmF0aW9uSW1wbFSmyJ1qZfv8DAAAeHB3kLZBABZTeXN0ZW1Nb2R1bGUtMCFRdWV1ZS0wAAtKTVNTZXJ2ZXItMAAOU3lzdGVtTW9kdWxlLTABAANBbGwCAlb6IS6T5qL/AAAACgEAC0FkbWluU2VydmVyAC2EGgJW+iEuk+ai/wAAAAsBAAtBZG1pblNlcnZlcgAthBoAAQAQX1dMU19BZG1pblNlcnZlcng=, ServerName=JMSServer-0, Topic=false, VersionNumber=1}) -r-- DestinationType Queue -r-- DurableSubscribers null -r-- InsertionPaused false -r-- InsertionPausedState Insertion-Enabled -r-- MessagesCurrentCount 0 -r-- MessagesDeletedCurrentCount 3 -r-- MessagesHighCount 2 -r-- MessagesMovedCurrentCount 0 -r-- MessagesPendingCount 0 -r-- MessagesReceivedCount 3 -r-- MessagesThresholdTime 0 -r-- Name SystemModule-0!Queue-0 -r-- Paused false -r-- ProductionPaused false -r-- ProductionPausedState Production-Enabled -r-- State advertised_in_cluster_jndi -r-- Type JMSDestinationRuntime   -r-x closeCursor Void : String(cursorHandle) -r-x deleteMessages Integer : String(selector) -r-x getCursorEndPosition Long : String(cursorHandle) -r-x getCursorSize Long : String(cursorHandle) -r-x getCursorStartPosition Long : String(cursorHandle) -r-x getItems javax.management.openmbean.CompositeData[] : String(cursorHandle),Long(start),Integer(count) -r-x getMessage javax.management.openmbean.CompositeData : String(cursorHandle),Long(messageHandle) -r-x getMessage javax.management.openmbean.CompositeData : String(cursorHandle),String(messageID) -r-x getMessage javax.management.openmbean.CompositeData : String(messageID) -r-x getMessages String : String(selector),Integer(timeout) -r-x getMessages String : String(selector),Integer(timeout),Integer(state) -r-x getNext javax.management.openmbean.CompositeData[] : String(cursorHandle),Integer(count) -r-x getPrevious javax.management.openmbean.CompositeData[] : String(cursorHandle),Integer(count) -r-x importMessages Void : javax.management.openmbean.CompositeData[],Boolean(replaceOnly) -r-x moveMessages Integer : String(java.lang.String),javax.management.openmbean.CompositeData,Integer(java.lang.Integer) -r-x moveMessages Integer : String(selector),javax.management.openmbean.CompositeData -r-x pause Void : -r-x pauseConsumption Void : -r-x pauseInsertion Void : -r-x pauseProduction Void : -r-x preDeregister Void : -r-x resume Void : -r-x resumeConsumption Void : -r-x resumeInsertion Void : -r-x resumeProduction Void : -r-x sort Long : String(cursorHandle),Long(start),String[](fields),Boolean[](ascending)   wls:/hotspot_domain/serverRuntime/JMSRuntime/AdminServer.jms/JMSServers/JMSServer-0/Destinations/SystemModule-0!Queue-0> cmo.deleteMessages('') 2 where the domain name is “hotspot_domain”, the JMS Server name is “JMSServer-0”, the Queue name is “Queue-0” and the System Module is named “SystemModule-0”.  To invoke the operation, I use the “cmo” object, which is the “Current Management Object” that represents the currently navigated to MBean.  The 2 indicates that two messages were deleted.  Combining this WLST code with a recent post by my colleague Steve that shows you how to use an encrypted file to store the authentication credentials, you could easily turn this into a secure automated script.  If you need help with that step, a long while back I blogged about some WLST basics.  Happy scripting.

    Read the article

  • Functional Adaptation

    - by Charles Courchaine
    In real life and OO programming we’re often faced with using adapters, DVI to VGA, 1/4” to 1/8” audio connections, 110V to 220V, wrapping an incompatible interface with a new one, and so on.  Where the adapter pattern is generally considered for interfaces and classes a similar technique can be applied to method signatures.  To be fair, this adaptation is generally used to reduce the number of parameters but I’m sure there are other clever possibilities to be had.  As Jan questioned in the last post, how can we use a common method to execute an action if the action has a differing number of parameters, going back to the greeting example it was suggested having an AddName method that takes a first and last name as parameters.  This is exactly what we’ll address in this post. Let’s set the stage with some review and some code changes.  First, our method that handles the setup/tear-down infrastructure for our WCF service: 1: private static TResult ExecuteGreetingFunc<TResult>(Func<IGreeting, TResult> theGreetingFunc) 2: { 3: IGreeting aGreetingService = null; 4: try 5: { 6: aGreetingService = GetGreetingChannel(); 7: return theGreetingFunc(aGreetingService); 8: } 9: finally 10: { 11: CloseWCFChannel((IChannel)aGreetingService); 12: } 13: } Our original AddName method: 1: private static string AddName(string theName) 2: { 3: return ExecuteGreetingFunc<string>(theGreetingService => theGreetingService.AddName(theName)); 4: } Our new AddName method: 1: private static int AddName(string firstName, string lastName) 2: { 3: return ExecuteGreetingFunc<int>(theGreetingService => theGreetingService.AddName(firstName, lastName)); 4: } Let’s change the AddName method, just a little bit more for this example and have it take the greeting service as a parameter. 1: private static int AddName(IGreeting greetingService, string firstName, string lastName) 2: { 3: return greetingService.AddName(firstName, lastName); 4: } The new signature of AddName using the Func delegate is now Func<IGreeting, string, string, int>, which can’t be used with ExecuteGreetingFunc as is because it expects Func<IGreeting, TResult>.  Somehow we have to eliminate the two string parameters before we can use this with our existing method.  This is where we need to adapt AddName to match what ExecuteGreetingFunc expects, and we’ll do so in the following progression. 1: Func<IGreeting, string, string, int> -> Func<IGreeting, string, int> 2: Func<IGreeting, string, int> -> Func<IGreeting, int>   For the first step, we’ll create a method using the lambda syntax that will “eliminate” the last name parameter: 1: string lastNameToAdd = "Smith"; 2: //Func<IGreeting, string, string, int> -> Func<IGreeting, string, int> 3: Func<IGreeting, string, int> addName = (greetingService, firstName) => AddName(greetingService, firstName, lastNameToAdd); The new addName method gets us one step close to the signature we need.  Let’s say we’re going to call this in a loop to add several names, we’ll take the final step from Func<IGreeting, string, int> -> Func<IGreeting, int> in line as a lambda passed to ExecuteGreetingFunc like so: 1: List<string> firstNames = new List<string>() { "Bob", "John" }; 2: int aID; 3: foreach (string firstName in firstNames) 4: { 5: //Func<IGreeting, string, int> -> Func<IGreeting, int> 6: aID = ExecuteGreetingFunc<int>(greetingService => addName(greetingService, firstName)); 7: Console.WriteLine(GetGreeting(aID)); 8: } If for some reason you needed to break out the lambda on line 6 you could replace it with 1: aID = ExecuteGreetingFunc<int>(ApplyAddName(addName, firstName)); and use this method: 1: private static Func<IGreeting, int> ApplyAddName(Func<IGreeting, string, int> addName, string lastName) 2: { 3: return greetingService => addName(greetingService, lastName); 4: } Splitting out a lambda into its own method is useful both in this style of coding as well as LINQ queries to improve the debugging experience.  It is not strictly necessary to break apart the steps & functions as was shown above; the lambda in line 6 (of the foreach example) could include both the last name and first name instead of being composed of two functions.  The process demonstrated above is one of partially applying functions, this could have also been done with Currying (also see Dustin Campbell’s excellent post on Currying for the canonical curried add example).  Matthew Podwysocki also has some good posts explaining both Currying and partial application and a follow up post that further clarifies the difference between Currying and partial application.  In either technique the ultimate goal is to reduce the number of parameters passed to a function.  Currying makes it a single parameter passed at each step, where partial application allows one to use multiple parameters at a time as we’ve done here.  This technique isn’t for everyone or every problem, but can be extremely handy when you need to adapt a call to something you don’t control.

    Read the article

  • Should functions of a C library always expect a string's length?

    - by Benjamin Kloster
    I'm currently working on a library written in C. Many functions of this library expect a string as char* or const char* in their arguments. I started out with those functions always expecting the string's length as a size_t so that null-termination wasn't required. However, when writing tests, this resulted in frequent use of strlen(), like so: const char* string = "Ugh, strlen is tedious"; libFunction(string, strlen(string)); Trusting the user to pass properly terminated strings would lead to less safe, but more concise and (in my opinion) readable code: libFunction("I hope there's a null-terminator there!"); So, what's the sensible practice here? Make the API more complicated to use, but force the user to think of their input, or document the requirement for a null-terminated string and trust the caller?

    Read the article

  • Binary serialization/de-serialization in C++ and C#

    - by 6pack kid
    Hello. I am working on a distributed application which has two components. One is written in standard C++ (not managed C++) and the other one is written in C#. Both are communicating via a message bus. I have a situation in which I need to pass objects from C++ to C# application and for this I need to serialize those objects in C++ and de-serialize them in C# (something like marshaling/un-marshaling in .NET). I need to perform this serialization in binary and not in XML (due to performance reasons). I have used Boost.Serialization to do this when both ends were implemented in C++ but now that I have a .NET application on one end, Boost.Serialization is not a viable solution. I am looking for a solution that allows me to perform (de)serialization across C++ and .NET boundary i.e., cross platform binary serialization. I know I can implement the (de)serialization code in a C++ dll and use P/Invoke in the .NET application, but I want to keep that as a last resort. Also, I want to know if I use some standard like gzip, will that be efficient? Are there any other alternatives to gzip? What are the pros/cons of them? Thanks

    Read the article

  • Parsing a Directory of files - Check for a String

    - by i.h4d35
    This is my first post here so kindly pardon any mistakes that I have. I'm still learning to find my way around Stack Exchange. I am trying to write a Java program that tries to scan a Directory full of either .txt,.rtf or.doc files(and none other). The aim is to search all the files in the directory, and find out if a particular string exists in the file. If it does, it returns the string and the filename that it found the string in. The aim of this program is, it is a project for school wherein the program scans the personal folders of call center employees to check if they have stored any CC/DC nos and if yes, report the folder name - to reduce CC fraud. The search function was fairly straight forward and works when I individually specify the filename. However, the searching the directory and passing the files to the search function has me stumped. I've posted my code so far, if you guys could look thru it and give me some feedback/suggestions, I'd really appreciate it. Thanks in advance import java.io.*; import java.util.*; public class parse2{ void traverse(String directory) throws FileNotFoundException { File dir = new File(directory); if (dir.isDirectory()) { String[] children = dir.list(); for (int i=0; i<children.length; i++) { //System.out.println("\n" + children[i]); reader(children[i]); } } } void reader(String loc) throws FileNotFoundException { FileReader fr = new FileReader(loc); BufferedReader br = new BufferedReader(fr); Scanner sc = new Scanner(br); char[] chkArray; int chk=1; char ch; while(sc.hasNext()) { String chkStr = sc.next(); chkArray = chkStr.toCharArray(); if ((chkArray[0]=='4')&&(chkStr.length()>13)) { for(int i=0;i<chkArray.length;i++) { ch=chkArray[i]; if((ch=='0')||(ch=='1')||(ch=='2')||(ch=='3')||(ch=='4')||(ch=='5')||(ch=='6')||(ch=='7')||(ch=='8')||(ch=='9')) { chk=0; continue; } else { chk=1; break; } } if(chk==0) System.out.println("\n"+ chkStr); } else if((chkArray[0]=='5')&&(chkStr.length()>13)) { for(int i=0;i<chkArray.length;i++) { ch=chkArray[i]; if((ch=='0')||(ch=='1')||(ch=='2')||(ch=='3')||(ch=='4')||(ch=='5')||(ch=='6')||(ch=='7')||(ch=='8')||(ch=='9')) { chk=0; continue; } else { chk=1; break; } } if(chk==0) System.out.println("\n"+ chkStr); } else if((chkArray[0]=='6')&&(chkStr.length()>13)) { for(int i=0;i<chkArray.length;i++) { ch=chkArray[i]; if((ch=='0')||(ch=='1')||(ch=='2')||(ch=='3')||(ch=='4')||(ch=='5')||(ch=='6')||(ch=='7')||(ch=='8')||(ch=='9')) { chk=0; continue; } else { chk=1; break; } } if(chk==0) System.out.println("\n"+ chkStr); } } } public static void main(String args[]) throws FileNotFoundException { parse2 P = new parse2(); P.traverse("C:/Documents and Settings/h4d35/Desktop/javatest/chk"); } }

    Read the article

  • How to map an IDictionary<String, CustomCollectionType> in NHibernate

    - by devonlazarus
    Very close to what I'm trying to do but not quite the answer I think I'm looking for: How to map IDictionary<string, Entity> in Fluent NHibernate I'm trying to implement an IDictionary<String, IList<MyEntity>>and map this collection to the database using NHibernate. I do understand that you cannot map collections of collections directly in NHibernate, but I do need the functionality of accessing an ordered list of elements by key. I've implemented IUserCollectionType for my IList<MyEntity> so that I can use IDictionary<String, MyCustomCollectionType> but am struggling with how to get the map to work as I'd like. Details This is the database I'm trying to model: ------------------------ -------------------- | EntityAttributes | | Entities | ------------------------ ------------------ -------------------- | EntityAttributeId PK | | Attributes | | EntityId PK | <- | EntityId FK | ------------------ | DateCreated | | AttributeId FK | -> | AttributeId PK | -------------------- | AttributeValue | | AttributeName | ------------------------ ------------------ Here are my domain classes: public class Entity { public virtual Int32 Id { get; private set; } public virtual DateTime DateCreated { get; private set; } ... } public class EavEntity : Entity { public virtual IDictionary<String, EavEntityAttributeList> Attributes { get; protected set; } ... } public class EavAttribute : Entity { public virtual String Name { get; set; } ... } public class EavEntityAttribute : Entity { public virtual EavEntity EavEntity { get; private set; } public virtual EavAttribute EavAttribute { get; private set; } public virtual Object AttributeValue { get; set; } ... } public class EavEntityAttributeList : List<EavEntityAttribute> { } I've also implemented the NH-specific custom collection classes IUserCollectionType and PersistentList And here is my mapping so far: <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" ...> <class xmlns="urn:nhibernate-mapping-2.2" name="EavEntity" table="Entities"> <id name="Id" type="System.Int32"> <column name="EntityId" /> <generator class="identity" /> </id> ... <map cascade="all-delete-orphan" collection-type="EavEntityAttributeListType" name="EntityAttributes"> <key> <column name="EntityId" /> </key> <index type="System.String"> <column name="Name" /> </index> <one-to-many class="EavEntityAttributeList" /> </map> </class> </hibernate-mapping> I know the <map> tag is partially correct, but I'm not sure how to get NH to utilize my IUserCollectionType to persist the model to the database. What I'd like to see (and this isn't right, I know) is something like: <map cascade="all-delete-orphan" collection-type="EavEntityAttributeListType" name="EntityAttributes"> <key> <column name="EntityId" /> </key> <index type="System.String"> <column name="Name" /> </index> <list> <index column="DisplayOrder"> <one-to-many class="EntityAttributes"> </list> </map> Does anyone have any suggestions on how to properly map that IDictionary<String, EavEntityAttributeList> collection? I am using Fluent NH so I'll take examples using that library, but I'm hand mappings are just as helpful here.

    Read the article

  • Looking to reimplement build toolchain from bash/grep/sed/awk/(auto)make/configure to something more

    - by wash
    I currently maintain a few boxes that house a loosely related cornucopia of coding projects, databases and repositories (ranging from a homebrew *nix distro to my class notes), maintained by myself and a few equally pasty-skinned nerdy friends (all of said cornucopia is stored in SVN). The vast majority of our code is in C/C++/assembly (a few utilities are in python/perl/php, we're not big java fans), compiled in gcc. Our build toolchain typically consists of a hodgepodge of make, bash, grep, sed and awk. Recent discovery of a Makefile nearly as long as the program it builds (as well as everyone's general anxiety with my cryptic sed and awking) has motivated me to seek a less painful build system. Currently, the strongest candidate I've come across is Boost Build/Bjam as a replacement for GNU make and python as a replacement for our build-related bash scripts. Are there any other C/C++/asm build systems out there worth looking into? I've browsed through a number of make alternatives, but I haven't found any that are developed by names I know aside from Boost's. (I should note that an ability to easily extract information from svn commandline tools such as svnversion is important, as well as enough flexibility to configure for builds of asm projects as easily as c/c++ projects)

    Read the article

  • C++ meta-splat function

    - by aaa
    hello. Is there an existing function (in boost mpl or fusion) to splat meta-vector to variadic template arguments? for example: splat<vector<T1, T2, ...>, function>::type same as function<T1, T2, ...> my search have not found one, and I do not want to reinvent one if it already exists. edit: after some tinkering, apparently it's next to impossible to accomplish this in general way, as it would require declaring full template template parameter list for all possible cases. only reasonable solution is to use macro: #define splat(name, function) \ template<class T, ...> struct name; \ template<class T> \ struct name<T,typename boost::enable_if_c< \ result_of::size<T>::value == 1>::type> { \ typedef function< \ typename result_of::value_at_c<T,0>::type \ > type; \ }; Oh well. thank you

    Read the article

  • How to handle 'this' pointer in constructor?

    - by Kyle
    I have objects which create other child objects within their constructors, passing 'this' so the child can save a pointer back to its parent. I use boost::shared_ptr extensively in my programming as a safer alternative to std::auto_ptr or raw pointers. So the child would have code such as shared_ptr<Parent>, and boost provides the shared_from_this() method which the parent can give to the child. My problem is that shared_from_this() cannot be used in a constructor, which isn't really a crime because 'this' should not be used in a constructor anyways unless you know what you're doing and don't mind the limitations. Google's C++ Style Guide states that constructors should merely set member variables to their initial values. Any complex initialization should go in an explicit Init() method. This solves the 'this-in-constructor' problem as well as a few others as well. What bothers me is that people using your code now must remember to call Init() every time they construct one of your objects. The only way I can think of to enforce this is by having an assertion that Init() has already been called at the top of every member function, but this is tedious to write and cumbersome to execute. Are there any idioms out there that solve this problem at any step along the way?

    Read the article

  • Is there a way to find out whether a class is a direct base of another class?

    - by user176168
    Hi I'm wondering whether there is a way to find out whether a class is a direct base of another class i.e. in boost type trait terms a is_direct_base_of function. As far as I can see boost doesn't see to support this kind of functionality which leads me to think that its impossible with the current C++ standard. The reason I want it is to do some validation checking on two macro's that are used for a reflection system to specify that one class is derived from another e.g. header.h: #define BASE A #define DERIVED B class A {}; class B : public A { #include <rtti.h> }; rtti.h: // I want to check that the two macro's are correct with a compile time assert Rtti<BASE, DERIVED> m_rtti; Although the macro's seem unnecessary in this simple example in my real world scenario rtti.h is a lot more complex. One possible avenue would be to compare the size of the this pointer with the size of a this pointer cast to the base type and some how trying to figure out whether its the size of the base class itself away or something (yeah your right I don't know how that would work either! lol)

    Read the article

  • A generic C++ library that provides QtConcurrent functionality?

    - by Lucas
    QtConcurrent is awesome. I'll let the Qt docs speak for themselves: QtConcurrent includes functional programming style APIs for parallel list processing, including a MapReduce and FilterReduce implementation for shared-memory (non-distributed) systems, and classes for managing asynchronous computations in GUI applications. For instance, you give QtConcurrent::map() an iterable sequence and a function that accepts items of the type stored in the sequence, and that function is applied to all the items in the collection. This is done in a multi-threaded manner, with a thread pool equal to the number of logical CPU's on the system. There are plenty of other function in QtConcurrent, like filter(), filteredReduced() etc. The standard CompSci map/reduce functions and the like. I'm totally in love with this, but I'm starting work on an OSS project that will not be using the Qt framework. It's a library, and I don't want to force others to depend on such a large framework like Qt. I'm trying to keep external dependencies to a minimum (it's the decent thing to do). I'm looking for a generic C++ framework that provides me with the same/similar high-level primitives that QtConcurrent does. AFAIK boost has nothing like this (I may be wrong though). boost::thread is very low-level compared to what I'm looking for. I know C# has something very similar with their Parallel Extensions so I know this isn't a Qt-only idea. What do you suggest I use?

    Read the article

  • C++ variable to const expression

    - by user1344784
    template <typename Real> class A{ }; template <typename Real> class B{ }; //... a few dozen more similar template classes class Computer{ public slots: void setFrom(int from){ from_ = from; } void setTo(int to){ to_ = to; } private: template <int F, int T> void compute(){ using boost::fusion::vector; using boost::fusion::at_c; vector<A<float>, B<float>, ...> v; at_c<from_>(v).operator()(at_c<to_>(v)); //error; needs to be const-expression. }; This question isn't about Qt, but there is a line of Qt code in my example. The setFrom() and setTo() are functions that are called based on user selection via the GUI widget. The root of my problem is that 'from' and 'to' are variables. In my compute member function I need to pick a type (A, B, etc.) based on the values of 'from' and 'to'. The only way I know how to do what I need to do is to use switch statements, but that's extremely tedious in my case and I would like to avoid. Is there anyway to convert the error line to a constant-expression?

    Read the article

  • Trying to convert string to datetime

    - by user1596472
    I am trying to restrict a user from entering a new record if the date requested already exits. I was trying to do a count to see if the table that the record would be placed in already has that date 1 or not 0. I have a calendar extender attached to a text box which has the date. I keep getting either a: String was not recognized as a valid DateTime. or Unable to cast object of type 'System.Web.UI.WebControls.TextBox' to type 'System.IConvertible'. depending on the different things I have tried. Here is my code. TextBox startd = (TextBox)(DetailsView1.FindControl("TextBox5")); TextBox endd = (TextBox)(DetailsView1.FindControl("TextBox7")); DropDownList lvtype = (DropDownList)(DetailsView1.FindControl("DropDownList6")); DateTime scheduledDate = DateTime.ParseExact(startd.Text, "dd/MM/yyyy", null); DateTime endDate = DateTime.ParseExact(endd.Text, "dd/MM/yyyy", null); DateTime newstartDate = Convert.ToDateTime(startd.Text); DateTime newendDate = Convert.ToDateTime(endd.Text); //foreach (DataRow row in sd.Tables[0].Rows) DateTime dt = newstartDate; while (dt <= newendDate) { //for retreiving from table Decimal sd = SelectCountDate(dt, lvtype.SelectedValue, countDate); String ndt = Convert.ToDateTime(dt).ToShortDateString(); // //start = string.CompareOrdinal(scheduledDate, ndt); // // end = string.CompareOrdinal(endDate, ndt); //trying to make say when leavetpe is greater than count 1 then throw error. if (sd > 0) { Response.Write("<script>alert('Date Already Requested');</script>"); } dt.AddDays(1); } ^^^ This version throws the: "String was not recognized as valid date type" error But if i replace the string with either of these : /*-----------------------Original------------------------------------ string scheduledDate = Convert.ToDateTime(endd).ToShortDateString(); string endDate = Convert.ToDateTime(endd).ToShortDateString(); -------------------------------------------------------------------*/ /*----------10-30--------------------------------------- DateTime scheduledDate = DateTime.Parse(startd.Text); DateTime endDate = DateTime.Parse(endd.Text); ------------------------------------------------------*/ I get the "Unable to cast object of type 'System.Web.UI.WebControls.TextBox' to type 'System.IConvertible'." error. I am just trying to stop a user from entering a record date that already exits. <InsertItemTemplate> <asp:TextBox ID="TextBox5" runat="server" Height="19px" Text='<%# Bind("lstdate", "{0:MM/dd/yyyy}") %>' Width="67px"></asp:TextBox> <asp:CalendarExtender ID="TextBox5_CalendarExtender" runat="server" Enabled="True" TargetControlID="TextBox5"> </asp:CalendarExtender> <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="TextBox5" ErrorMessage="*Leave Date Required" ForeColor="Red"></asp:RequiredFieldValidator> <br /> <asp:CompareValidator ID="CompareValidator18" runat="server" ControlToCompare="TextBox7" ControlToValidate="TextBox5" ErrorMessage="Leave date cannot be after start date" ForeColor="Red" Operator="LessThanEqual" ToolTip="Must choose start date before end date"></asp:CompareValidator> </InsertItemTemplate>

    Read the article

< Previous Page | 102 103 104 105 106 107 108 109 110 111 112 113  | Next Page >