org.basex.query.xpath.expr
Class FTIntersection

java.lang.Object
  extended by org.basex.query.ExprInfo
      extended by org.basex.query.xpath.expr.Expr
          extended by org.basex.query.xpath.expr.FTArrayExpr
              extended by org.basex.query.xpath.expr.FTIntersection

public final class FTIntersection
extends FTArrayExpr

FTIntersection Expression. This expresses the intersection of two FTContains results.

Author:
Workgroup DBIS, University of Konstanz 2005-08, ISC License, Sebastian Gath

Field Summary
 
Fields inherited from class org.basex.query.xpath.expr.FTArrayExpr
fto
 
Constructor Summary
FTIntersection(FTArrayExpr[] e, int[] pexpr, int[] nexpr)
          Constructor.
 
Method Summary
 Bln eval(XPContext ctx)
          Evaluates the expression with the specified context set.
 boolean more()
          Checks for more results.
 FTNode next(XPContext ctx)
          Returns the next ftquery result.
 boolean pos()
          Checks whether the result of the expression is negative.
 
Methods inherited from class org.basex.query.xpath.expr.FTArrayExpr
comp, indexEquivalent, indexOptions, plan, toString, usesPos, usesSize
 
Methods inherited from class org.basex.query.xpath.expr.Expr
indexSizes, returnedValue, sameAs
 
Methods inherited from class org.basex.query.ExprInfo
color, info, name
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

FTIntersection

public FTIntersection(FTArrayExpr[] e,
                      int[] pexpr,
                      int[] nexpr)
Constructor.

Parameters:
e - operands joined with the union operator
pexpr - IntList with indexes of positive expressions
nexpr - IntList with indexes of negative expressions
Method Detail

pos

public boolean pos()
Description copied from class: FTArrayExpr
Checks whether the result of the expression is negative.

Overrides:
pos in class FTArrayExpr
Returns:
boolean

more

public boolean more()
Description copied from class: FTArrayExpr
Checks for more results.

Overrides:
more in class FTArrayExpr
Returns:
boolean

next

public FTNode next(XPContext ctx)
Description copied from class: FTArrayExpr
Returns the next ftquery result.

Overrides:
next in class FTArrayExpr
Parameters:
ctx - current context
Returns:
FTNode container for the next result

eval

public Bln eval(XPContext ctx)
         throws QueryException
Description copied from class: Expr
Evaluates the expression with the specified context set. Additionally provides a context

Specified by:
eval in class Expr
Parameters:
ctx - query context
Returns:
resulting XPathValue
Throws:
QueryException - evaluation exception