org.basex.query.xpath.internal
Class FTIndex

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.internal.FTIndex

public final class FTIndex
extends FTArrayExpr

This expression retrieves the ids of indexed fulltext terms.

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

Field Summary
 
Fields inherited from class org.basex.query.xpath.expr.FTArrayExpr
fto
 
Constructor Summary
FTIndex(byte[] tok, FTOpt o)
          Constructor.
 
Method Summary
 Bln eval(XPContext ctx)
          Evaluates the expression with the specified context set.
 FTArrayExpr indexEquivalent(XPContext ctx, Step curr, boolean seq)
          Returns an equivalent expression which accesses an index structure.
 int indexSizes(XPContext ctx, Step curr, int min)
          Returns the number of results if this query is evaluated by an index.
 boolean more()
          Checks for more results.
 FTNode next(XPContext ctx)
          Returns the next ftquery result.
 void plan(Serializer ser)
          Recursively sends the abstract syntax of this expression to the specified serializer.
 java.lang.String toString()
           
 
Methods inherited from class org.basex.query.xpath.expr.FTArrayExpr
comp, indexOptions, pos, usesPos, usesSize
 
Methods inherited from class org.basex.query.xpath.expr.Expr
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

FTIndex

public FTIndex(byte[] tok,
               FTOpt o)
Constructor.

Parameters:
tok - index token
o - FTOption for index token
Method Detail

indexEquivalent

public FTArrayExpr indexEquivalent(XPContext ctx,
                                   Step curr,
                                   boolean seq)
Description copied from class: Expr
Returns an equivalent expression which accesses an index structure.

Overrides:
indexEquivalent in class FTArrayExpr
Parameters:
ctx - root
curr - location step
seq - flag for sequential evaluation
Returns:
Equivalent index-expression or null

eval

public Bln eval(XPContext ctx)
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

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

indexSizes

public int indexSizes(XPContext ctx,
                      Step curr,
                      int min)
Description copied from class: Expr
Returns the number of results if this query is evaluated by an index. If Integer.MAX_VALUE is returned, no index access is possible.

Overrides:
indexSizes in class Expr
Parameters:
ctx - root
curr - the current location step
min - current minimum index hits
Returns:
number of expected results

plan

public void plan(Serializer ser)
          throws java.io.IOException
Description copied from class: ExprInfo
Recursively sends the abstract syntax of this expression to the specified serializer.

Overrides:
plan in class FTArrayExpr
Parameters:
ser - serializer
Throws:
java.io.IOException - exception

toString

public java.lang.String toString()
Overrides:
toString in class FTArrayExpr