/* * Example 5: Hashed dictionaries * * This program uses RWCollectableStrings as keys * and RWCollectableInts as values. * * $Id: hashdict.cpp,v 7.7 1996/08/07 05:21:24 hart Exp $ * * Copyright (c) 1989-1999 Rogue Wave Software, Inc. All Rights Reserved. * * This computer software is owned by Rogue Wave Software, Inc. and is * protected by U.S. copyright laws and other laws and by international * treaties. This computer software is furnished by Rogue Wave Software, * Inc. pursuant to a written license agreement and may be used, copied, * transmitted, and stored only in accordance with the terms of such * license and with the inclusion of the above copyright notice. This * computer software or any other copies thereof may not be provided or * otherwise made available to any other person. * * U.S. Government Restricted Rights. This computer software is provided * with Restricted Rights. Use, duplication, or disclosure by the * Government is subject to restrictions as set forth in subparagraph (c) * (1) (ii) of The Rights in Technical Data and Computer Software clause * at DFARS 252.227-7013 or subparagraphs (c) (1) and (2) of the * Commercial Computer Software – Restricted Rights at 48 CFR 52.227-19, * as applicable. Manufacturer is Rogue Wave Software, Inc., 5500 * Flatiron Parkway, Boulder, Colorado 80301 USA. * *************************************************************************** */ /* * Declarations for class RWCollectableString: * This class inherits class RWCString and class RWCollectable. * Class RWCollectable has virtual functions hash() and matches() that are * redefined by class RWCollectableString. These functions are used to * insert and retrieve RWCollectableStrings in the hash table. */ #include "rw/collstr.h" // Declarations for class RWCollectableInt: #include "rw/collint.h" // Declarations for RWHashDictionary: #include "rw/hashdict.h" #include "rw/rstream.h" STARTWRAP #include ENDWRAP #ifdef applec # define RW_END_PROMPT endl << flush #else # define RW_END_PROMPT flush #endif // The following can easily be changed to store and retrieve // keys and values of other types: typedef RWCollectableString KeyType; typedef RWCollectableInt ValueType; // The following can be changed to use a different container class; // for example, a B-Tree: typedef RWHashDictionary DictionaryType; /* Global function to print keys and values. This function is handed to * RWHashDictionary::apply(). */ void printKeyAndValue( RWCollectable* ky, RWCollectable* val, void*); // prototype void printKeyAndValue( RWCollectable* ky, RWCollectable* val, void*) { /* * If we're using the Standard C++ Library and the iostream operators * are in the std namespace, we need to pull in namespace std, or * scope the operator with std::. */ #if !defined(RW_NO_STL) && !defined(RW_NO_STD_NAMESPACE) && !defined(RW_NO_IOSTD) using namespace std; #endif /* * borland 4 needs the std namespace */ #if defined(RW_BCB_NAMESPACE) using namespace std; #endif /* Do the necessary typecast, then print 'em out: */ cout << *(const KeyType*) ky << "\t" << *(const ValueType*)val << endl; } int main() { #if !defined(RW_NO_STL) && !defined(RW_NO_STD_NAMESPACE) && !defined(RW_NO_IOSTD) using namespace std; #endif /* * borland 4 needs the std namespace */ #if defined(RW_BCB_NAMESPACE) using namespace std; #endif cout << "***************Example of Hash Dictionary *****************\n\n"; // Construct a dictionary with no entries: DictionaryType dictionary; // Loop to do various things to the Dictionary: // Since the Dictionary stores pointers to keys and values, storage will be // provided from the heap for the actual keys and values. KeyType* theKey; // pointer to key. ValueType* theValue; // pointer to value. KeyType aKey; // Test key. char option; // Options for switch. RWCollectable* retVal; // used to hold return values RWCString wasteBin; // Receptacle for erroneous input. do { cout << dictionary.entries() << " entries in dictionary.\n"; cout << "(i)nsert (f)ind (d)elete (l)ist (c)lear e(x)it:\t" << RW_END_PROMPT; // Borland bug necessitates explicit test for .good(): if ( !(cin >> option).good() ) break; // Check for EOF switch ( option ) { case 'i': // Insert a key-value pair. case 'I': cout << "Enter word to act as key:\t" << RW_END_PROMPT; theKey = new KeyType; // Allocate from the heap. cin >> *theKey; cout << "Enter int to act as value:\t" << RW_END_PROMPT; theValue = new ValueType; // Allocate from the heap. if(cin.good()) cin >> *theValue; if(cin.good()) //Has all the input been good? retVal = dictionary.insertKeyAndValue(theKey, theValue); else { //If bad input received. cin.clear(0); //Flag the stream as good. wasteBin.readLine(cin); //Flush input buffer into wasteBin cout << "\n" << wasteBin << " is not a valid int value, please try again.\n\n"; break; } cout << "\nKey " << *theKey; if (retVal) cout << " with value " << *theValue << " entered.\n\n"; else cout << " already exists in dictionary.\n\n"; break; case 'f': // Find a value, given a test key. case 'F': cout << "Enter word to find:\t" << RW_END_PROMPT; cin >> aKey; theValue = (ValueType*)dictionary.findValue(&aKey); if ( theValue ) cout << "\n" << aKey << " is a member of the collection with value " << *theValue << "\n\n"; else cout << "\n" << aKey << " is not a member of the collection.\n\n"; break; case 'd': // Delete a key. case 'D': cout << "Enter word to be deleted:\t" << RW_END_PROMPT; cin >> aKey; RWCollectable* temp; // Temporary necessary to calm cfront down theKey = (KeyType*)dictionary.removeKeyAndValue(&aKey, temp); if(theKey){ theValue = (ValueType*)temp; cout << "\n" << "Key " << *theKey << " with value " << *theValue << " removed.\n\n"; delete theKey; delete theValue; } else cout << "\n" << "Key " << aKey << " not found.\n\n"; break; case 'l': // List contents of Dictionary. case 'L': // Uses global function defined above: dictionary.applyToKeyAndValue(printKeyAndValue, rwnil); cout << "\n"; break; case 'c': // Clear the Dictionary case 'C': dictionary.clearAndDestroy(); cout << "\n"; // Program will state "0 entries" break; case 'x': case 'X': break; default: cerr << "\nNot recognized.\n\n"; } // end switch } while (option != 'x' && option != 'X') ; return 0; }