SetOperator (rdfpro 0.6 API)

java.lang.Object
- eu.fbk.rdfpro.SetOperator

All Implemented Interfaces:

Serializable, Comparable<SetOperator>
```
public abstract class SetOperator
extends Object
implements Serializable, Comparable<SetOperator>
```
A set/multiset operator.

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`static SetOperator`	`DIFFERENCE` Set difference.
`static SetOperator`	`DIFFERENCE_MULTISET` Multiset difference.
`static SetOperator`	`INTERSECTION` Set intersection.
`static SetOperator`	`INTERSECTION_MULTISET` Multiset intersection.
`static SetOperator`	`SUM_MULTISET` Multiset sum (a.k.a.
`static SetOperator`	`SYMMETRIC_DIFFERENCE` Set symmetric difference.
`static SetOperator`	`SYMMETRIC_DIFFERENCE_MULTISET` Multiset symmetric difference.
`static SetOperator`	`UNION` Set union.
`static SetOperator`	`UNION_MULTISET` Multiset union.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`abstract int`	`apply(int[] multiplicities)` Applies the operator.
`static SetOperator`	`atLeast(int n)` At least N occurrences.
`static SetOperator`	`atMost(int n)` At most N occurrences.
`int`	`compareTo(SetOperator other)` Comparison is based on the textual representation of set operators.
`boolean`	`equals(Object object)` Equality is implemented based on the textual representation of set operators.
`int`	`hashCode()` The hash code is computed based on the textual representation of the set operator.
`String`	`toString()` Returns the textual representation of the set operator that uniquely identifies it.
`static SetOperator`	`valueOf(String string)` Returns the `SetOperator` for the textual representation supplied.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - UNION
```
public static final SetOperator UNION
```
    Set union. This SetOperator ignores duplicates and returns a unique copy of an element only if it occurs at least in one of the arguments of the operation. The corresponding textual representation is "u".
  - UNION_MULTISET
```
public static final SetOperator UNION_MULTISET
```
    Multiset union. This SetOperator returns an element if it occurs in at least one argument of the operation, with a multiplicity equal to the one of the argument it occurs the most. The corresponding textual representation is "U". See this page for more information.
  - SUM_MULTISET
```
public static final SetOperator SUM_MULTISET
```
    Multiset sum (a.k.a. union all). This SetOperator returns an element if it occurs at least in one argument of the operation, with a multiplicity that is the sum of the multiplicities of the element in the multisets coming from the operation arguments. The corresponding textual representation is "a". See this page for more information.
  - INTERSECTION
```
public static final SetOperator INTERSECTION
```
    Set intersection. This SetOperator ignores duplicates and returns an element only if it occurs in all the arguments of the operation. In that case, exactly one copy of the element is emitted. The corresponding textual representation is "i".
  - INTERSECTION_MULTISET
```
public static final SetOperator INTERSECTION_MULTISET
```
    Multiset intersection. This SetOperator returns an element if it occurs in all the arguments of the operation, with a multiplicity equal to the one of the argument it occurs the least. The corresponding textual representation is "I". See this page for more information.
  - DIFFERENCE
```
public static final SetOperator DIFFERENCE
```
    Set difference. This SetOperator ignores duplicates and returns the set difference between the first argument (index 0) on one side, and all the other arguments on the other side (i.e., A0 \ A1 ... \An or equivalently A0 \ (A1 U ... U An)). At most a copy of a given element is returned. The corresponding textual representation is "d".
  - DIFFERENCE_MULTISET
```
public static final SetOperator DIFFERENCE_MULTISET
```
    Multiset difference. This SetOperator returns the multiset difference between the first argument (index 0) on one side, and all the other arguments on the other side (i.e., A0 \ A1 ... \An or equivalently A0 \ (A1 + ... + An) where + denotes multiset sum). The multiplicity of a returned element is equal to its multiplicity in the first argument minus the sum of its multiplicities in the other arguments (rounded to 0 if negative). The corresponding textual representation is "D". See this page for more information.
  - SYMMETRIC_DIFFERENCE
```
public static final SetOperator SYMMETRIC_DIFFERENCE
```
    Set symmetric difference. This SetOperator ignores duplicates and returns all the elements that are present in at least one argument of the operator but not in all of them. For two arguments, this corresponds to evaluating (A0 \ A1) U (A1 \ A0). At most a copy of an element is returned. The corresponding textual representation is "s".
  - SYMMETRIC_DIFFERENCE_MULTISET
```
public static final SetOperator SYMMETRIC_DIFFERENCE_MULTISET
```
    Multiset symmetric difference. This SetOperator returns the elements that are present in at least one argument of the operator, with a multiplicity that is the difference between the multiplicity in the argument it occurs the most and the multiplicity in the argument it occurs the least. For two arguments, this corresponds to evaluating (the multiset version of) (A0 \ A1) U (A1 \ A0). The corresponding textual representation is "S". See this page for more information.
- Method Detail
  - atLeast
```
public static SetOperator atLeast(int n)
```
    At least N occurrences. Creates a parametric SetOperator that checks that the total number of occurrences of a certain element, summed over all the operation arguments and counting duplicates, is AT LEAST N. In that case a single copy of the element is emitted. The corresponding textual representation is "N+".
    
    Parameters:
    
    n - the threshold, greater or equal to 1
    
    Returns:
    
    the created SetOperator object
  - atMost
```
public static SetOperator atMost(int n)
```
    At most N occurrences. Creates a parametric SetOperator that checks that the total number of occurrences of a certain element, summed over all the operation arguments and counting duplicates, is AT MOST N. In that case a single copy of the element is emitted. The corresponding textual representation is "N-".
    
    Parameters:
    
    n - the threshold, greater or equal to 1
    
    Returns:
    
    the created SetOperator object
  - apply
```
public abstract int apply(int[] multiplicities)
```
    Applies the operator. The method is called for a given element, supplying it the multiplicities of the element in each argument (a set or a multiset) of the operation. The method returns the multiplicity of the element in the operation result.
    
    Parameters:
    
    multiplicities - the multiplicities of the element in the operation arguments (non-null, non-empty array)
    
    Returns:
    
    the resulting multiplicity
  - compareTo
```
public final int compareTo(SetOperator other)
```
    Comparison is based on the textual representation of set operators.
    
    Specified by:
    
    compareTo in interface Comparable<SetOperator>
  - equals
```
public final boolean equals(Object object)
```
    Equality is implemented based on the textual representation of set operators.
    
    Overrides:
    
    equals in class Object
  - hashCode
```
public final int hashCode()
```
    The hash code is computed based on the textual representation of the set operator.
    
    Overrides:
    
    hashCode in class Object
  - toString
```
public final String toString()
```
    Returns the textual representation of the set operator that uniquely identifies it.
    
    Overrides:
    
    toString in class Object
  - valueOf
```
public static SetOperator valueOf(String string)
```
    Returns the SetOperator for the textual representation supplied.
    
    Parameters:
    
    string - the textual representation, not null
    
    Returns:
    
    the corresponding SetOperator, upon success

Class SetOperator

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

UNION

UNION_MULTISET

SUM_MULTISET

INTERSECTION

INTERSECTION_MULTISET

DIFFERENCE

DIFFERENCE_MULTISET

SYMMETRIC_DIFFERENCE

SYMMETRIC_DIFFERENCE_MULTISET

Method Detail

atLeast

atMost

apply

compareTo

equals

hashCode

toString

valueOf