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  • C++ HW - defining classes - objects that have objects of other class problem in header file (out of

    - by kitfuntastik
    This is my first time with much of this code. With this instancepool.h file below I get errors saying I can't use vector (line 14) or have instance& as a return type (line 20). It seems it can't use the instance objects despite the fact that I have included them. #ifndef _INSTANCEPOOL_H #define _INSTANCEPOOL_H #include "instance.h" #include <iostream> #include <string> #include <vector> #include <stdlib.h> using namespace std; class InstancePool { private: unsigned instances;//total number of instance objects vector<instance> ipp;//the collection of instance objects, held in a vector public: InstancePool();//Default constructor. Creates an InstancePool object that contains no Instance objects InstancePool(const InstancePool& original);//Copy constructor. After copying, changes to original should not affect the copy that was created. ~InstancePool();//Destructor unsigned getNumberOfInstances() const;//Returns the number of Instance objects the the InstancePool contains. const instance& operator[](unsigned index) const; InstancePool& operator=(const InstancePool& right);//Overloading the assignment operator for InstancePool. friend istream& operator>>(istream& in, InstancePool& ip);//Overloading of the >> operator. friend ostream& operator<<(ostream& out, const InstancePool& ip);//Overloading of the << operator. }; #endif Here is the instance.h : #ifndef _INSTANCE_H #define _INSTANCE_H ///////////////////////////////#include "instancepool.h" #include <iostream> #include <string> #include <stdlib.h> using namespace std; class Instance { private: string filenamee; bool categoryy; unsigned featuress; unsigned* featureIDD; unsigned* frequencyy; string* featuree; public: Instance (unsigned features = 0);//default constructor unsigned getNumberOfFeatures() const; //Returns the number of the keywords that the calling Instance object can store. Instance(const Instance& original);//Copy constructor. After copying, changes to the original should not affect the copy that was created. ~Instance() { delete []featureIDD; delete []frequencyy; delete []featuree;}//Destructor. void setCategory(bool category){categoryy = category;}//Sets the category of the message. Spam messages are represented with true and and legit messages with false.//easy bool getCategory() const;//Returns the category of the message. void setFileName(const string& filename){filenamee = filename;}//Stores the name of the file (i.e. “spam/spamsga1.txt”, like in 1st assignment) in which the message was initially stored.//const string& trick? string getFileName() const;//Returns the name of the file in which the message was initially stored. void setFeature(unsigned i, const string& feature, unsigned featureID,unsigned frequency) {//i for array positions featuree[i] = feature; featureIDD[i] = featureID; frequencyy[i] = frequency; } string getFeature(unsigned i) const;//Returns the keyword which is located in the ith position.//const string unsigned getFeatureID(unsigned i) const;//Returns the code of the keyword which is located in the ith position. unsigned getFrequency(unsigned i) const;//Returns the frequency Instance& operator=(const Instance& right);//Overloading of the assignment operator for Instance. friend ostream& operator<<(ostream& out, const Instance& inst);//Overloading of the << operator for Instance. friend istream& operator>>(istream& in, Instance& inst);//Overloading of the >> operator for Instance. }; #endif Also, if it is helpful here is instance.cpp: // Here we implement the functions of the class apart from the inline ones #include "instance.h" #include <iostream> #include <string> #include <stdlib.h> using namespace std; Instance::Instance(unsigned features) { //Constructor that can be used as the default constructor. featuress = features; if (features == 0) return; featuree = new string[featuress]; // Dynamic memory allocation. featureIDD = new unsigned[featuress]; frequencyy = new unsigned[featuress]; return; } unsigned Instance::getNumberOfFeatures() const {//Returns the number of the keywords that the calling Instance object can store. return featuress;} Instance::Instance(const Instance& original) {//Copy constructor. filenamee = original.filenamee; categoryy = original.categoryy; featuress = original.featuress; featuree = new string[featuress]; for(unsigned i = 0; i < featuress; i++) { featuree[i] = original.featuree[i]; } featureIDD = new unsigned[featuress]; for(unsigned i = 0; i < featuress; i++) { featureIDD[i] = original.featureIDD[i]; } frequencyy = new unsigned[featuress]; for(unsigned i = 0; i < featuress; i++) { frequencyy[i] = original.frequencyy[i];} } bool Instance::getCategory() const { //Returns the category of the message. return categoryy;} string Instance::getFileName() const { //Returns the name of the file in which the message was initially stored. return filenamee;} string Instance::getFeature(unsigned i) const { //Returns the keyword which is located in the ith position.//const string return featuree[i];} unsigned Instance::getFeatureID(unsigned i) const { //Returns the code of the keyword which is located in the ith position. return featureIDD[i];} unsigned Instance::getFrequency(unsigned i) const { //Returns the frequency return frequencyy[i];} Instance& Instance::operator=(const Instance& right) { //Overloading of the assignment operator for Instance. if(this == &right) return *this; delete []featureIDD; delete []frequencyy; delete []featuree; filenamee = right.filenamee; categoryy = right.categoryy; featuress = right.featuress; featureIDD = new unsigned[featuress]; frequencyy = new unsigned[featuress]; featuree = new string[featuress]; for(unsigned i = 0; i < featuress; i++) { featureIDD[i] = right.featureIDD[i]; } for(unsigned i = 0; i < featuress; i++) { frequencyy[i] = right.frequencyy[i]; } for(unsigned i = 0; i < featuress; i++) { featuree[i] = right.featuree[i]; } return *this; } ostream& operator<<(ostream& out, const Instance& inst) {//Overloading of the << operator for Instance. out << endl << "<message file=" << '"' << inst.filenamee << '"' << " category="; if (inst.categoryy == 0) out << '"' << "legit" << '"'; else out << '"' << "spam" << '"'; out << " features=" << '"' << inst.featuress << '"' << ">" <<endl; for (int i = 0; i < inst.featuress; i++) { out << "<feature id=" << '"' << inst.featureIDD[i] << '"' << " freq=" << '"' << inst.frequencyy[i] << '"' << "> " << inst.featuree[i] << " </feature>"<< endl; } out << "</message>" << endl; return out; } istream& operator>>(istream& in, Instance& inst) { //Overloading of the >> operator for Instance. string word; string numbers = ""; string filenamee2 = ""; bool categoryy2 = 0; unsigned featuress2; string featuree2; unsigned featureIDD2; unsigned frequencyy2; unsigned i; unsigned y; while(in >> word) { if (word == "<message") {//if at beginning of message in >> word;//grab filename word for (y=6; word[y]!='"'; y++) {//pull out filename from between quotes filenamee2 += word[y];} in >> word;//grab category word if (word[10] == 's') categoryy2 = 1; in >> word;//grab features word for (y=10; word[y]!='"'; y++) { numbers += word[y];} featuress2 = atoi(numbers.c_str());//convert string of numbers to integer Instance tempp2(featuress2);//make a temporary Instance object to hold values read in tempp2.setFileName(filenamee2);//set temp object to filename read in tempp2.setCategory(categoryy2); for (i=0; i<featuress2; i++) {//loop reading in feature reports for message in >> word >> word >> word;//skip two words numbers = "";//reset numbers string for (int y=4; word[y]!='"'; y++) {//grab feature ID numbers += word[y];} featureIDD2 = atoi(numbers.c_str()); in >> word;// numbers = ""; for (int y=6; word[y]!='"'; y++) {//grab frequency numbers += word[y];} frequencyy2 = atoi(numbers.c_str()); in >> word;//grab actual feature string featuree2 = word; tempp2.setFeature(i, featuree2, featureIDD2, frequencyy2); }//all done reading in and setting features in >> word;//read in last part of message : </message> inst = tempp2;//set inst (reference) to tempp2 (tempp2 will be destroyed at end of function call) return in; } } } and instancepool.cpp: // Here we implement the functions of the class apart from the inline ones #include "instancepool.h" #include "instance.h" #include <iostream> #include <string> #include <vector> #include <stdlib.h> using namespace std; InstancePool::InstancePool()//Default constructor. Creates an InstancePool object that contains no Instance objects { instances = 0; ipp.clear(); } InstancePool::~InstancePool() { ipp.clear();} InstancePool::InstancePool(const InstancePool& original) {//Copy constructor. instances = original.instances; for (int i = 0; i<instances; i++) { ipp.push_back(original.ipp[i]); } } unsigned InstancePool::getNumberOfInstances() const {//Returns the number of Instance objects the the InstancePool contains. return instances;} const Instance& InstancePool::operator[](unsigned index) const {//Overloading of the [] operator for InstancePool. return ipp[index];} InstancePool& InstancePool::operator=(const InstancePool& right) {//Overloading the assignment operator for InstancePool. if(this == &right) return *this; ipp.clear(); instances = right.instances; for(unsigned i = 0; i < instances; i++) { ipp.push_back(right.ipp[i]); } return *this; } istream& operator>>(istream& in, InstancePool& ip) {//Overloading of the >> operator. ip.ipp.clear(); string word; string numbers; int total;//int to hold total number of messages in collection while(in >> word) { if (word == "<messagecollection"){ in >> word;//reads in total number of all messages for (int y=10; word[y]!='"'; y++){ numbers = ""; numbers += word[y]; } total = atoi(numbers.c_str()); for (int x = 0; x<total; x++) {//do loop for each message in collection in >> ip.ipp[x];//use instance friend function and [] operator to fill in values and create Instance objects and read them intot he vector } } } } ostream& operator<<(ostream& out, const InstancePool& ip) {//Overloading of the << operator. out << "<messagecollection messages=" << '"' << '>' << ip.instances << '"'<< endl << endl; for (int z=0; z<ip.instances; z++) { out << ip[z];} out << endl<<"</messagecollection>\n"; } This code is currently not writing to files correctly either at least, I'm sure it has many problems. I hope my posting of so much is not too much, and any help would be very much appreciated. Thanks!

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  • nonatomic property in model class when using NSOperationQueue (iPhone)?

    - by Andrew B.
    I have a custom model class with an NSMutableData ivar that will be accessed by custom NSOperation subclasses (using an NSOperationQueue). I think I can guarantee thread-safe access to the ivar from multiple NSOperations by using dependencies, and I can guarantee that I don't access the ivar from other code (say my main app thread) by waiting until the Q has finished all operations. Should I use a nonatomic property specification, or leave it atomic? Is there a significant impact on performance?

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  • how to have two controller actions, one shared view for Zend_Controller_Action Class?

    - by arendn
    Hi Guys, How do you specify a custom view script for a given Controller Action method? For example: Class UserGalleryController extends Zend_Controller_Action { public function fooAction() { $this->view->actionMsg = 'foo'; // (uses foo.phtml automagically) } public function barAction() { $this->view->actionMsg = 'bar'; //use foo's view script ????? } } I basically want to have one view script (foo.phtml) Thanks :-)

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  • Better way to write an object generator for an RAII template class?

    - by Dan
    I would like to write an object generator for a templated RAII class -- basically a function template to construct an object using type deduction of parameters so the types don't have to be specified explicitly. The problem I foresee is that the helper function that takes care of type deduction for me is going to return the object by value, which will result in a premature call to the RAII destructor when the copy is made. Perhaps C++0x move semantics could help but that's not an option for me. Anyone seen this problem before and have a good solution? This is what I have: template<typename T, typename U, typename V> class FooAdder { private: typedef OtherThing<T, U, V> Thing; Thing &thing_; int a_; // many other members public: FooAdder(Thing &thing, int a); ~FooAdder(); void foo(T t, U u); void bar(V v); }; The gist is that OtherThing has a horrible interface, and FooAdder is supposed to make it easier to use. The intended use is roughly like this: FooAdder(myThing, 2) .foo(3, 4) .foo(5, 6) .bar(7) .foo(8, 9); The FooAdder constructor initializes some internal data structures. The foo and bar methods populate those data structures. The ~FooAdder dtor wraps things up and calls a method on thing_, taking care of all the nastiness. That would work fine if FooAdder wasn't a template. But since it is, I would need to put the types in, more like this: FooAdder<Abc, Def, Ghi>(myThing, 2) ... That's annoying, because the types can be inferred based on myThing. So I would prefer to create a templated object generator, similar to std::make_pair, that will do the type deduction for me. Something like this: template<typename T, typename U, typename V> FooAdder<T, U, V> AddFoo(Thing &thing, int a) { return FooAdder<T, U, V>(thing, a); } That seems problematic: because it returns by value, the stack temporary object will be destructed, which will cause the RAII dtor to run prematurely. One thought I had was to give FooAdder a copy ctor with move semantics, kinda like std::auto_ptr. But I would like to do this without dynamic memory allocation, so I thought the copy ctor could set a flag within FooAdder indicating the dtor shouldn't do the wrap-up. Like this: FooAdder(FooAdder &rhs) // Note: rhs is not const : thing_(rhs.thing_) , a_(rhs.a_) , // etc... lots of other members, annoying. , moved(false) { rhs.moved = true; } ~FooAdder() { if (!moved) { // do whatever it would have done } } Seems clunky. Anyone got a better way?

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  • Is it bad practice to 'mix class and interfaces in the same package'?

    - by DerMike
    Hello, I just found something that I never heard of before and I do not agree with (by now). In an (upvoted and not further commented) answer I read "why to mix class and interfaces in the same package" So I wonder, if there are reasons to separate Interfaces and implementations in Java. I know that we are not obliged to have all implementations in the package of the interface, but is it (sometimes) wise to have none there? Regards Mike [;-)

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  • How i can i use the value of a variable from one class in another in objective c?

    - by user337174
    Hi i am fairly new to objective c and have been doing some iphone programming. Is it possible to look up the value of a variable in a different class? Basically what i am doing is running a function that exists in my app delegate from a view controller, but the app delegate needs to use a variable stored in the view controller from which the app delegate function was called. Make sense??? Any help would be grateful. James

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  • I need a dictionary-like mapping between characters and other kinds of objects. Which class would be

    - by nullPointerException
    This is in Squeak/Pharo. If I want to have a mapping between Character objects like $a and $b to other kinds of objects, and want to look up those other objects based on the Character, what is the best class to use? Dictionary is an obvious choice, but seems wasteful to be hashing character objects which are basically already numbers. I guess what I want is a kind of array where the character value (number) is used as an index/offset, but I am not sure if this is possible with Unicode.

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