Set

Creating Sets

Use the function createSet defined in the header <Util.h>. The following is the syntax to declare a set:

static Set* createSet(DATA_TYPE keyType, INDEX capacity);

Arguments

• keyType: The data type for the elements of the created set, such as DT_INT, DT_DATE, etc.
• capacity: The amount of memory (in terms of the number of elements) allocated to the set.

Examples

SetSP set = Util::createSet(DT_INT, 100);    //create a set of INT type with a reserved capacity of 100 elements

Operations on Sets

Listed below are some commonly utilized functions for operations on sets:

bool append(const ConstantSP& value);                                         //append 'value' to a set
bool remove(const ConstantSP& value);                                         //remove 'value' from a set
void contain(const ConstantSP& target, const ConstantSP& resultSP) const;     //determine if a set contains the element 'target' 
INDEX size() const;                                                           //get the number of elements in a set
void clear();                                                                 //remove all elements from a set

Examples

set->append(new Int(3));                      //（3）
set->append(new Int(1));                      //(3, 1)
set->append(new Int(2));                      //(3, 1, 2)
set->append(new Int(2));                      //(3, 1, 2)
ConstantSP result = new Bool;
set->contain(new Int(3), result);             //result : true
set->contain(new Int(4), result);             //result : false
set->remove(new Int(1));                      //(2, 3)
set->remove(new Int(4));                      //(2, 3)
std::cout << set->size();                     //2
set->clear();