g++ [flags ...] file ...

#include <HashTable.h>

HashTable(ALLOCATION alloc = SYSTEM, long initial_capacity =
          DEF_CAPACITY, float load_factor = DEF_LOAD_FACTOR));
TObject* get(const THashable& key);
const TObject* get(const THashable& key) const;
boolean insert(THashable& key, TObject* value);
boolean keys(Vector& keys_list) const;
boolean values(Vector<TObject>& items_list) const;

// declare a character hash table and insert a character in it
//
HashTable<String,Char> table0;
Char item(L'a');
String key(L"test_key");
table0.insert(key, &item);

// get the item out
//
if(table0.get(key)->ne(item)) {

  // error
  //
}

T. Cormen, C. Leiserson, R. Rivest, Introduction to Algorithms, MIT Press, Boston, Massachusetts, USA, pp. 219-243, 1998.

• This example shows how to use a HashTable in SYSTEM mode (the default):

  #include <HashTable.h>
         
  int main() {
  
    // local variables
    //
    HashTable<String, Long> ages;
    String name;
    Long age;
  
    // insert 4 peoples names and ages
    //
    name.assign(L"Rick");
    age.assign(23);
    ages.insert(name, &age);
  
    name.assign(L"Jon");
    age.assign(26);
    ages.insert(name, &age);
  
    name.assign(L"Shivali");
    age.assign(24);
    ages.insert(name, &age);
  
    name.assign(L"Issac");
    age.assign(21);
    ages.insert(name, &age);
  
    // extract a name and print out the age
    //
    name.assign(L"Rick");
    ages.get(name)->debug(L"Rick's age");
  
    // delete Shivali's entry
    //
    name.assign(L"Shivali");
    ages.remove(name);
    
    // exit gracefully
    //
    Integral::exit();
  } 
         

• This example shows how to use a HashTable in USER mode. Note that we have to allocate object memory by hand and make sure it is deleted.

  #include <HashTable.h>
         
  int main() {
  
    // local variables
    //
    HashTable<String, Long> ages(USER);
    String name;
    Long* age;
  
    // insert 4 peoples names and ages
    //
    name.assign(L"Rick");
    age = new Long(23);
    ages.insert(name, age);
  
    name.assign(L"Jon");
    age = new Long(26);
    ages.insert(name, age);
  
    name.assign(L"Shivali");
    age = new Long(24);
    ages.insert(name, age);
  
    name.assign(L"Issac");
    age = new Long(21);
    ages.insert(name, age);
  
    // extract a name and print out the age
    //
    name.assign(L"Rick");
    ages.get(name)->debug(L"Rick's age");
  
    // remove Shivali's entry
    //
    name.assign(L"Shivali");
    age = (Long*)NULL;
    ages.remove(name, age);
    delete age;
  
    // cleanup memory
    //
    ages.clear(Integral::FREE);
  }
  

• There are two memory allocation modes for HashTable as indicated by the protected member data, alloc_d. The default allocation mode is SYSTEM. In SYSTEM mode the HashTable handles allocation and deletion of the objects. In other words, the HashTable makes copies of whatever objects are passed in. In USER mode the whatever object is passed in is stored directly, so the USER must make sure that the memory is allocated and deleted.
  
  
• Note that internally the List objects will always be in SYSTEM mode. The only difference for USER and SYSTEM mode will be controlled manually via the Node class inside the HashNode.
  
  
• Unlike other classes, we have two read and write methods in dstr classes. The interface is still the same as that in other classes. The reason behind this is that we can not use "CLASS_NAME" as default argument in the read and write methods here because the data structures build the class name on the fly.