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  • Java Concurrency in practice sample question

    - by andy boot
    I am reading "Java Concurrency in practice" and looking at the example code on page 51. According to the book this piece of code is at risk of of failure if it has not been published properly. Because I like to code examples and break them to prove how they work. I have tried to make it throw an AssertionError but have failed. (Leading me to my previous question) Can anyone post sample code so that an AssertionError is thrown? Rule: Do not modify the Holder class. public class Holder{ private int n; public Holder(int n){ this.n = n; } public void assertSanity(){ if (n != n) { throw new AssertionError("This statement is false"); } } } I have modified the class to make it more fragile but I still can not get an AssertionError thrown. class Holder2{ private int n; private int n2; public Holder2(int n) throws InterruptedException{ this.n = n; Thread.sleep(200); this.n2 = n; } public void assertSanity(){ if (n != n2) { throw new AssertionError("This statement is false"); } } } Is it possible to make either of the above classes throw an AssertionError? Or do we have to accept that they may occasionally do so and we can't write code to prove it?

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  • Calculate pixels within a polygon

    - by DoomStone
    In an assignment for school do we need to do some image recognizing, where we have to find a path for a robot. So far have we been able to find all the polygons in the image, but now we need to generate a pixel map, that be used for an astar algorithm later. We have found a way to do this, show below, but the problem is that is very slow, as we go though each pixel and test if it is inside the polygon. So my question is, are there a way that we can generate this pixel map faster? We have a list of cordinates for the polygon private List<IntPoint> hull; The fuction "getMap" is called to get the pixel map public Point[] getMap() { List<Point> points = new List<Point>(); lock (hull) { Rectangle rect = getRectangle(); for (int x = rect.X; x <= rect.X + rect.Width; x++) { for (int y = rect.Y; y <= rect.Y + rect.Height; y++) { if (inPoly(x, y)) points.Add(new Point(x, y)); } } } return points.ToArray(); } Get Rectangle is used to limit the search, se we don't have to go thoug the whole image public Rectangle getRectangle() { int x = -1, y = -1, width = -1, height = -1; foreach (IntPoint item in hull) { if (item.X < x || x == -1) x = item.X; if (item.Y < y || y == -1) y = item.Y; if (item.X > width || width == -1) width = item.X; if (item.Y > height || height == -1) height = item.Y; } return new Rectangle(x, y, width-x, height-y); } And atlast this is how we check to see if a pixel is inside the polygon public bool inPoly(int x, int y) { int i, j = hull.Count - 1; bool oddNodes = false; for (i = 0; i < hull.Count; i++) { if (hull[i].Y < y && hull[j].Y >= y || hull[j].Y < y && hull[i].Y >= y) { try { if (hull[i].X + (y - hull[i].X) / (hull[j].X - hull[i].X) * (hull[j].X - hull[i].X) < x) { oddNodes = !oddNodes; } } catch (DivideByZeroException e) { if (0 < x) { oddNodes = !oddNodes; } } } j = i; } return oddNodes; }

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  • Basic Custom String Class for C++

    - by wdow88
    Hey all, I'm working on building my own string class with very basic functionality. I am having difficulty understand what is going on with the basic class that I have define, and believe there is some sort of error dealing with the scope occurring. When I try to view the objects I created, all the fields are described as (obviously bad pointer). Also, if I make the data fields public or build an accessor method, the program crashes. For some reason the pointer for the object is 0xccccccccc which points to no where. How can a I fix this? Any help/comments are much appreciated. //This is a custom string class, so far the only functions are //constructing and appending #include<iostream> using namespace std; class MyString1 { public: MyString1() { //no arg constructor char *string; string = new char[0]; string[0] ='\0'; std::cout << string; size = 1; } //constructor receives pointer to character array MyString1(char* chars) { int index = 0; //Determine the length of the array while (chars[index] != NULL) index++; //Allocate dynamic memory on the heap char *string; string = new char[index+1]; //Copy the contents of the array pointed by chars into string, the char array of the object for (int ii = 0; ii < index; ii++) string[ii] = chars[ii]; string[index+1] = '\0'; size = index+1; } MyString1 append(MyString1 s) { //determine new size of the appended array and allocate memory int newsize = s.size + size; MyString1 MyString2; char *newstring; newstring = new char[newsize+1]; int index = 0; //load the first string into the array while (string[index] != NULL) { newstring[index] = string[index]; index++; } //load the second string while (s.string[index] != NULL) { newstring[index] = s.string[index]; index++; } //null terminate newstring[newsize+1] = '\0'; delete string; //generate the object for return MyString2.string=newstring; MyString2.size=newsize; return MyString2; } private: char *string; int size; }; int main() { MyString1 string1; MyString1 string2("Hello There"); MyString1 string3("Buddy"); string2.append(string3); return 0; }

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  • Web Services in Blackberry

    - by Farhan
    Hi, i am working on CallLogs Sync Application in Blackberry and partially i have done it, one point that i didn't understand is how to add information to CallLogs. I have retrieved information from CallLogs and Store on Server but now i retrieved information from Server but how to add info to CallLogs didn't come in my mind as i retrieved all the information in Strings from Server and PhoneCallLog Constructor look like this: PhoneCallLog call = new PhoneCallLog(Date,int Type,int Duration,int Status,participantID participant,String Notes); Please tell me as soon as Possible, i will be very thankful to you.

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  • How to debug when CakePHP Model::save() doesn't attempt an INSERT

    - by RyOnLife
    I am having a bear of a time saving the simplest record from a model called ItemView: if($this->save($this->data)) { echo 'worked'; } else { echo 'failed'; } Where $this-data is: Array ( [ItemView] => Array ( [list_id] => 1 [user_id] => 1 ) ) And my table is: CREATE TABLE IF NOT EXISTS `item_views` ( `id` int(11) NOT NULL auto_increment, `list_id` int(11) NOT NULL, `user_id` int(11) default NULL, `user_ip` int(10) unsigned default NULL, `created` datetime NOT NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 ROW_FORMAT=FIXED AUTO_INCREMENT=1 ; Looking at the query dump in debug mode, Cake isn't even attempting an INSERT, so I have no idea how to debug. Any help would be appreciated.

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  • How to compute the dot product?

    - by WizardOfOdds
    I have the following piece of pseudo-C/Java/C# code: int a[]= { 30, 20 }; int b[] = { 40, 50 }; int c[] = {12, 12}; How do I compute the sign of the dot-product AB . AC? I'm only interested in the sign, so I have: boolean signABxAC = ? Now concretely what do I write to get the sign of the dot-product AB . AC?

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  • Object does not exist after constructor?

    - by openbas
    Hello, I have a constructor that looks like this (in c++): Interpreter::Interpreter() { tempDat == new DataObject(); tempDat->clear(); } the constructor of dataObject does absolutely nothing, and clear does this: bool DataObject::clear() { //clear the object if (current_max_id > 0) { indexTypeLookup.clear(); intData.clear(); doubleData.clear(); current_max_id = 0; } } Those members are defined as follows: std::map<int, int> indexTypeLookup; std::map<int, int> intData; std::map<int, double> doubleData; Now the strange thing is that I'm getting a segfault on tempDat-clear(); gdb says tempDat is null. How is that possible? The constructor of tempDat cannot fail, it looks like this: DataObject::DataObject() : current_max_id(0) { } I know there are probably better way's of making such a data structure, but I really like to know where this segfault problem is coming from..

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  • Select columns from join table only without requiring a join

    - by Kent Boogaart
    Given these tables: create table Orders ( Id INT IDENTITY NOT NULL, primary key (Id) ) create table Items ( Id INT IDENTITY NOT NULL, primary key (Id) ) create table OrdersItems ( OrderId INT not null, ItemId INT not null, primary key (OrderId, ItemId) ) Is it possible to use HQL/criteria API to contruct a query that results in the following SQL: SELECT [OrderId], [ItemId] FROM [OrdersItems] I've tried both of these approaches: var hqlResults = session .CreateQuery("select order.id, item.id from Order order inner join order.Items item") .List(); var criteriaResults = session .CreateCriteria<Order>() .CreateAlias("Items", "item", NHibernate.SqlCommand.JoinType.None) .SetProjection(Projections.Property("id"), Projections.Property("item.id")) .List(); But both approaches insist on generating a join (or fail because the join isn't present, in using criteria), resulting in SQL such as: select order.Id, item.Id from Orders order inner join OrdersItems ordersItems on order.Id = ordersItems.ArticleId inner join Items item on ordersItems.CategoryId = item.Id Is there any way to have NHibernate generate a query that selects columns only from the join table, without requiring a join?

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  • xml and external swf documents

    - by VideoDnd
    My XML scripts work fine in the local swf. If I load an external swf, can I still retreive XML data from the same way, or do I have to declare the root somewhere? It's a general question. I know that when animating external swf files, you have to set it up differently, if so I would like an example, and a pitcher of beer. It's St. Patrick's weekend. SAMPLE CODE ONLY XML <?xml version="1.0" encoding="utf-8"?> <SESSION> <COUNT TITLE="starting position">-77777</COUNT> </SESSION> loader swf 'nodes' //grab the data as a string myString = myXML.COUNT.text(); //grab the data as an int count = int(myXML.COUNT.text()); external swf 'variables' var myString:String = ""; var count:int = int(myString); trace(count);

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  • Replicating Java's DecimalFormat in C#

    - by Frank Krueger
    I am trying to replicate a subset of Java's DecimalFormat class. Below is what I've come up with. Does this look right to everyone? public class DecimalFormat : NumberFormat { int _maximumFractionDigits; int _minimumFractionDigits; string _format; void RebuildFormat () { _format = "{0:0."; _format += new string ('0', _minimumFractionDigits); if (_maximumFractionDigits > _minimumFractionDigits) { _format += new string ('#', _maximumFractionDigits - _minimumFractionDigits); } _format += "}"; } public override string format (object value) { return string.Format (_format, value); } public override void setMaximumFractionDigits (int n) { _maximumFractionDigits = n; RebuildFormat (); } public override void setMinimumFractionDigits (int n) { _minimumFractionDigits = n; RebuildFormat (); } public override void setGroupingUsed (bool g) { } public static NumberFormat getInstance () { return new DecimalFormat (); } }

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  • Output is different for R-value and L-value. Why?

    - by Leonid Volnitsky
    Can someone explain to me why output for R-value is different from L-value? #include <iostream> #include <vector> using namespace std; template<typename Ct> struct ct_wrapper { Ct&& ct; // R or L ref explicit ct_wrapper(Ct&& ct) : ct(std::forward<Ct>(ct)) { std::cout << this->ct[1];}; }; int main() { // L-val vector<int> v{1,2,3}; ct_wrapper<vector<int>&> lv(v); cout << endl << lv.ct[0] << lv.ct[1] << lv.ct[2] << endl; // R-val ct_wrapper<vector<int>&&> rv(vector<int>{1,2,3}); cout << endl << rv.ct[0] << rv.ct[1] << rv.ct[2] << endl; } Output (same for gcc48 and clang32): 2 123 2 003

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  • Elapsed time of running a C program

    - by yCalleecharan
    Hi, I would like to know what lines of C code to add to a program so that it tells me the total time that the program takes to run. I guess there should be counter initialization near the beginning of main and one after the main function ends. Is the right header clock.h? Thanks a lot... Update I have a Win Xp machine. Is it just adding clock() at the beginning and another clock() at the end of the program? Then I can estimate the time difference. Yes, you're right it's time.h. Here's my code: #include <stdio.h> #include <stdlib.h> #include <math.h> #include <share.h> #include <time.h> void f(long double fb[], long double fA, long double fB); int main() { clock_t start, end; start = clock(); const int ARRAY_SIZE = 11; long double* z = (long double*) malloc(sizeof (long double) * ARRAY_SIZE); int i; long double A, B; if (z == NULL) { printf("Out of memory\n"); exit(-1); } A = 0.5; B = 2; for (i = 0; i < ARRAY_SIZE; i++) { z[i] = 0; } z[1] = 5; f(z, A, B); for (i = 0; i < ARRAY_SIZE; i++) printf("z is %.16Le\n", z[i]); free(z); z = NULL; end = clock(); printf("Took %ld ticks\n", end-start); printf("Took %f seconds\n", (double)(end-start)/CLOCKS_PER_SEC); return 0; } void f(long double fb[], long double fA, long double fB) { fb[0] = fb[1]* fA; fb[1] = fb[1] - 1; return; } Some errors with MVS2008: testim.c(16) : error C2143: syntax error : missing ';' before 'const' testim.c(18) :error C2143: syntax error : missing ';' before 'type' testim.c(20) :error C2143: syntax error : missing ';' before 'type' testim.c(21) :error C2143: syntax error : missing ';' before 'type' testim.c(23) :error C2065: 'z' : undeclared identifier testim.c(23) :warning C4047: '==' : 'int' differs in levels of indirection from 'void *' testim.c(28) : error C2065: 'A' : undeclared identifier testim.c(28) : warning C4244: '=' : conversion from 'double' to 'int', possible loss of data and it goes to 28 errors. Note that I don't have any errors/warnings without your clock codes. LATEST NEWS: I unfortunately didn't get a good reply here. But after a search on Google, the code is working. Here it is: #include <stdio.h> #include <stdlib.h> #include <math.h> #include <share.h> #include <time.h> void f(long double fb[], long double fA, long double fB); int main() { clock_t start = clock(); const int ARRAY_SIZE = 11; long double* z = (long double*) malloc(sizeof (long double) * ARRAY_SIZE); int i; long double A, B; if (z == NULL) { printf("Out of memory\n"); exit(-1); } A = 0.5; B = 2; for (i = 0; i < ARRAY_SIZE; i++) { z[i] = 0; } z[1] = 5; f(z, A, B); for (i = 0; i < ARRAY_SIZE; i++) printf("z is %.16Le\n", z[i]); free(z); z = NULL; printf("Took %f seconds\n", ((double)clock()-start)/CLOCKS_PER_SEC); return 0; } void f(long double fb[], long double fA, long double fB) { fb[0] = fb[1]* fA; fb[1] = fb[1] - 1; return; } Cheers

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  • How do I send the mutable string to the NSTextField properly?

    - by Merle
    So I have all this code that I have debugged and it seems to be fine. I made a mutable string and for some reason I can not get it to be displayed on my label. the debugger says "2010-04-22 22:50:26.126 Fibonacci[24836:10b] * -[NSTextField setString:]: unrecognized selector sent to instance 0x130150" What is wrong with this? When I just send the string to NSLog, it comes out fine. here's all my code, any help would be appreciated. "elementNum" is a comboBox and "display" is a Label. Thanks #import "Controller.h" @implementation Controller - (IBAction)computeNumber:(id)sender { int x = 1; int y = 1; NSMutableString *numbers = [[NSMutableString alloc] init]; [numbers setString:@"1, 1,"]; int num = [[elementNum objectValueOfSelectedItem]intValue]; int count = 1; while (count<=num) { int z = y; y+=x; x=z; [numbers appendString:[NSString stringWithFormat:@" %d,", y]]; count++; } [display setString:numbers]; NSLog(numbers); } @end `

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  • Formula to draw pyramid of circles

    - by terence6
    I'm trying to create a pyramid of circles to my game, looking similar to this : But I can't make it print properly. Constantly I'm getting really strange spirals but nothing close to this. Can anyone give me some tip on proper formula ? My window is 600x600, base of pyramid is 8 . fields = new Field[BASE*(BASE/2)+4]; int line_count = BASE; int line_tmp = line_count; for(int i=0; i< fields.length; i++){ for( int j=line_tmp; j <= line_count; j++){ fields[i] = new Field(0, (150+(line_tmp*5)),(600+line_tmp*5)); } line_count--; line_tmp = line_count; }

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  • Android Alert Dialog Extract User Choice Radio Button?

    - by kel196
    Apologies for any coding ignorance, I am a beginner and am still learning! I am creating a quiz app which reads questions off a SQL database and plots them as points on a google map. As the user clicks each point, an alert dialog appears with radio buttons to answer some question. My radiobuttons are in CustomItemizedOverlay file and when I click submit, I want to be able to send the user choice back to the database, save it and return to the user if their answer is correct. My question is this, how do I pass the user choice out once the submit button has been clicked? I tried making a global variable to read what was selected to no avail. Any suggestions would be appreciated! If I need to post any other code, please ask and I will do so ASAP! package uk.ac.ucl.cege.cegeg077.uceskkw; import java.util.ArrayList; import android.app.AlertDialog; import android.content.Context; import android.content.DialogInterface; import android.graphics.drawable.Drawable; import android.widget.Toast; import com.google.android.maps.ItemizedOverlay; import com.google.android.maps.OverlayItem; public class CustomItemizedOverlay2 extends ItemizedOverlay<OverlayItem> { private ArrayList<OverlayItem> mapOverlays = new ArrayList<OverlayItem>(); private Context context; public CustomItemizedOverlay2(Drawable defaultMarker) { super(boundCenterBottom(defaultMarker)); } public CustomItemizedOverlay2(Drawable defaultMarker, Context context) { this(defaultMarker); this.context = context; } @Override protected OverlayItem createItem(int i) { return mapOverlays.get(i); } @Override public int size() { return mapOverlays.size(); } @Override protected boolean onTap(int index) { OverlayItem item = mapOverlays.get(index); // gets the snippet from ParseKMLAndDisplayOnMap and splits it back into // a string. final CharSequence allanswers[] = item.getSnippet().split("::"); AlertDialog.Builder dialog = new AlertDialog.Builder(context); dialog.setIcon(R.drawable.easterbunnyegg); dialog.setTitle(item.getTitle()); dialog.setSingleChoiceItems(allanswers, -1, new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int whichButton) { Toast.makeText(context, "You have selected " + allanswers[whichButton], Toast.LENGTH_SHORT).show(); } }); dialog.setPositiveButton(R.string.button_submit, new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int whichButton) { dialog.dismiss(); // int selectedPosition = ((AlertDialog) // dialog).getListView().getCheckedItemPosition(); Toast.makeText(context, "hi!", Toast.LENGTH_SHORT) .show(); } }); dialog.setNegativeButton(R.string.button_close, new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int whichButton) { dialog.dismiss(); // on cancel button action } }); AlertDialog question = dialog.create(); question.show(); return true; } public void addOverlay(OverlayItem overlay) { mapOverlays.add(overlay); this.populate(); } }

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  • Consing lists with user-defined type in Haskell

    - by user1319603
    I have this type I defined myself: data Item = Book String String String Int -- Title, Author, Year, Qty | Movie String String String Int -- Title, Director, Year, Qty | CD String String String Int deriving Show -- Title, Artist, Year, Qty I've created an empty list all_Items = [] With the following function I am trying to insert a new book of type Item (Book) into the all_Items addBook all_Items = do putStrLn "Enter the title of the book" tit <- getLine putStrLn "Enter the author of the book" aut <- getLine putStrLn "Enter the year this book was published" yr <- getLine putStrLn "Enter quantity of copies for this item in the inventory" qty <- getLine Book tit aut yr (read qty::Int):all_Items return(all_Items) I however am receiving this error: Couldn't match expected type `IO a0' with actual type `[a1]' The error points to the line where I am using the consing operator to add the new book to the list. I can gather that it is a type error but I can't figure out what it is that I am doing wrong and how to fix it. Thanks in Advance!

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  • How to call memcmp() on two parts of byte[] (with offset)?

    - by brickner
    Hi, I want to compare parts of byte[] efficiently - so I understand memcmp() should be used. I know I can using PInvoke to call memcmp() - http://stackoverflow.com/questions/43289/comparing-two-byte-arrays-in-net But, I want to compare only parts of the byte[] - using offset, and there is no memcmp() with offset since it uses pointers. int CompareBuffers(byte[] buffer1, int offset1, byte[] buffer2, int offset2, int count) { // Somehow call memcmp(&buffer1+offset1, &buffer2+offset2, count) } Should I use C++/CLI to do that? Should I use PInvoke with IntPtr? How? Thank you.

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  • Returning a collection of objects from a webmethod

    - by Narmatha Balasundaram
    How do I return a collection of objects from a webmethod? And can this collection of objects be of different types - say of these 3 classes, private class ClassA { int A1; int A2; } private class ClassB { int B1; } private class ClassC { int C1; } ClassA objA = new ClassA(...); ClassB objB = new ClassB(...); ClassC objC = new ClassC(...); How can I return the objects, objA, objB and objC from a method?

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  • How Can I Reference Multiple Primary Keys For A Vector Type Primary Key

    - by AndreiC
    Hi, I have the following scenario: a table of projects and a table of persons, working on one or serveral projects. Also, I have a project id column (of type int), in the first table, which is a primary key there and I have a vector of project ids, as a column of type int, in my second table (persons), that references primary keys from the first table. What is the correct syntax for referencing multiple primary keys, from a vector foreign key. This is the way I am trying to create the table, but I am not sure what to place at the indicated line: CREATE TABLE Persons( Person_Id int, ..., ProjectsList int[], FOREIGN KEY (ProjectsList) REFERENCES Projects(Project_id) -- not sure what how to define the link here ); I hope my explanations are not over-complicated. Thank you in advance for helping!

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  • How to properly translate the "var" result of a lambda expression to a concrete type?

    - by CrimsonX
    So I'm trying to learn more about lambda expressions. I read this question on stackoverflow, concurred with the chosen answer, and have attempted to implement the algorithm using a console app in C# using a simple LINQ expression. My question is: how do I translate the "var result" of the lambda expression into a usable object that I can then print the result? I would also appreciate an in-depth explanation of what is happening when I declare the outer => outer.Value.Frequency (I've read numerous explanations of lambda expressions but additional clarification would help) C# //Input : {5, 13, 6, 5, 13, 7, 8, 6, 5} //Output : {5, 5, 5, 13, 13, 6, 6, 7, 8} //The question is to arrange the numbers in the array in decreasing order of their frequency, preserving the order of their occurrence. //If there is a tie, like in this example between 13 and 6, then the number occurring first in the input array would come first in the output array. List<int> input = new List<int>(); input.Add(5); input.Add(13); input.Add(6); input.Add(5); input.Add(13); input.Add(7); input.Add(8); input.Add(6); input.Add(5); Dictionary<int, FrequencyAndValue> dictionary = new Dictionary<int, FrequencyAndValue>(); foreach (int number in input) { if (!dictionary.ContainsKey(number)) { dictionary.Add(number, new FrequencyAndValue(1, number) ); } else { dictionary[number].Frequency++; } } var result = dictionary.OrderByDescending(outer => outer.Value.Frequency); // How to translate the result into something I can print??

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  • How do I use Some/None Options in this F# example?

    - by Phobis
    I am new to F# and I have this code: if s.Contains("-") then let x,y = match s.Split [|'-'|] with | [|a;b|] -> int a, int b | _ -> 0,0 Notice that we validate that there is a '-' in the string before we split the string, so the match is really unnecessary. Can I rewrite this with Options? I changed this code, it was originally this (but I was getting a warning): if s.Contains("-") then let [|a;b|] = s.Split [|'-'|] let x,y = int a, int b NOTE: I am splitting a range of numbers (range is expressed in a string) and then creating the integer values that represent the range's minimum and maximum.

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  • Objective-c Method to get a number then countdown in 1 every second

    - by Sami
    Hi, i need a little help i have a method which gets value such as 50, it then assigns that value to trackDuration, so NSNumber *trackDuration = 50, i want the method to every second minus 1 from the value of trackDuration and update a label, the label being called duration. Here's what i have so far; - (void) countDown { iTunesApplication *iTunes = [SBApplication applicationWithBundleIdentifier:@"com.apple.iTunes"]; NSNumber *trackDuration = [NSNumber numberWithDouble:[[iTunes currentTrack] duration]]; while (trackDuration > 0) { trackDuration - 1; int inputSeconds = [trackDuration intValue]; int hours = inputSeconds / 3600; int minutes = ( inputSeconds - hours * 3600 ) / 60; int seconds = inputSeconds - hours * 3600 - minutes * 60; NSString *trackDurationString = [NSString stringWithFormat:@"%.2d:%.2d:%.2d", hours, minutes, seconds]; [duration setStringValue:trackDurationString]; sleep(1); }} Any help would be much appreciated, thanks in advanced, Sami.

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  • doubt in sizeof implementation

    - by aks
    Below is the program to find the size of a structure without using sizeof operator: struct MyStruct { int i; int j; }; int main() { struct MyStruct *p=0; int size = ((char*)(p+1))-((char*)p); printf("\nSIZE : [%d]\nSIZE : [%d]\n", size); return 0; } My doubt is: Why is typecasting to char * required? If I don't use the char* pointer, the output is 1 - WHY?

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  • Why wont my while loop take new input (c++)

    - by Van
    I've written a program to get a string input from a user and parse it into tokens and move a robot according to the input. My problem is trying to issue more than one command. The code looks like: void Navigator::manualDrive() { const int bufSize = 42; char uinput[bufSize]; char delim[] = " "; char *token; while(true) { Navigator::parseInstruction(uinput); } } /* parseInstruction(char *c) -- parses cstring instructions received * and moves robot accordingly */ void Navigator::parseInstruction(char * c) { const int bufSize = 42; char uinput[bufSize]; char delim[] = " "; char *token; cout << "Enter your directions below: \n"; cin.ignore(); cin.getline (uinput, bufSize); token=strtok(uinput, delim); if(strcmp("forward", token) == 0) { int inches; token = strtok(NULL, delim); inches = atoi (token); Navigator::travel(inches); } if(strcmp("back",token) == 0) { int inches; token = strtok(NULL, delim); inches = atoi (token); double value = fabs(0.0735 * fabs(inches) - 0.0550); myRobot.backward(1/*speed*/, value/*time*/); } if(strcmp("turn",token) == 0) { int degrees; token = strtok(NULL, delim); if(strcmp("left",token) == 0) { token = strtok(uinput, delim); degrees = atoi (token); double value = fabs(0.0041 * degrees - 0.0523); myRobot.turnLeft(1/*speed*/, value/*time*/); } } if(strcmp("turn",token) == 0) { int degrees; token = strtok(NULL, delim); if(strcmp("right",token) == 0) { token = strtok(uinput, delim); degrees = atoi (token); double value = fabs(0.0041 * degrees - 0.0523); myRobot.turnRight(1/*speed*/, value/*time*/); } } if(strcmp("stop",token) == 0) { myRobot.motors(0,0); } } In the function manualDrive I have a while loop calling the function parseInstruction infinitely. The program outputs "Enter your directions below: " When I give the program instructions it executes them, and then it outputs "enter your directions below: " again and when I input my directions again it does not execute them and outputs "Enter your directions below: " instead. I'm sure this is a very simple fix I'm just very new to c++. So if you could please help me out and tell me why the program only takes the first set of directions. thanks

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