org.basex.query.xpath.expr
Class FTSelect

java.lang.Object
  org.basex.query.ExprInfo
      org.basex.query.xpath.expr.Expr
          org.basex.query.xpath.expr.FTArrayExpr
              org.basex.query.xpath.expr.FTSelect

public final class FTSelect
extends FTArrayExpr

Fulltext position filter expression and FTTimes.

Author:

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

Field Summary

FTPosFilter

ftpos FTPositionFilter.

Fields inherited from class org.basex.query.xpath.expr.FTArrayExpr

fto

Constructor Summary

FTSelect(FTArrayExpr e, FTPosFilter ftps)
Constructor.

Method Summary

boolean	checkSumUp(FTPosFilter ftpos1) Checks if FTContains Expr could be summed up.
FTArrayExpr	comp(XPContext ctx) Optimizes the expression.
Item	eval(XPContext ctx) Evaluates the expression with the specified context set.
FTArrayExpr	getExpr() Getter for expr.
FTArrayExpr	indexEquivalent(XPContext ctx, Step curr, boolean seq) Returns an equivalent expression which accesses an index structure.
boolean	indexOptions(MetaData meta) Verifies if the fulltext query options comply with the index defaults.
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.
boolean	pos() Checks whether the result of the expression is negative.
void	setExpr(FTArrayExpr e) Setter expr.

Methods inherited from class org.basex.query.xpath.expr.FTArrayExpr

plan, toString, 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

Field Detail

ftpos

public FTPosFilter ftpos

FTPositionFilter.

Constructor Detail

FTSelect

public FTSelect(FTArrayExpr e,
                FTPosFilter ftps)

Constructor.

Parameters:

e - expressions

ftps - FTPositionFilter

Method Detail

comp

public FTArrayExpr comp(XPContext ctx)
                 throws QueryException

Description copied from class: FTArrayExpr

Optimizes the expression.

Overrides:

comp in class FTArrayExpr

Parameters:

ctx - expression context

Returns:

optimized Expression

Throws:

QueryException - evaluation exception

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

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

getExpr

public FTArrayExpr getExpr()

Getter for expr.

Returns:

expr FTArrayExpr

setExpr

public void setExpr(FTArrayExpr e)

Setter expr.

Parameters:

e - FTArrayExpr

more

public boolean more()

Description copied from class: FTArrayExpr

Checks for more results.

Overrides:

more in class FTArrayExpr

Returns:

boolean

eval

public Item 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

indexOptions

public boolean indexOptions(MetaData meta)

Description copied from class: FTArrayExpr

Verifies if the fulltext query options comply with the index defaults. Check where this method is overwritten to get more info.

Overrides:

indexOptions in class FTArrayExpr

Parameters:

meta - meta data

Returns:

result of check

indexEquivalent

public FTArrayExpr indexEquivalent(XPContext ctx,
                                   Step curr,
                                   boolean seq)
                            throws QueryException

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

Throws:

QueryException - evaluation exception

checkSumUp

public boolean checkSumUp(FTPosFilter ftpos1)

Checks if FTContains Expr could be summed up.

Parameters:

ftpos1 - FTPositionFilter second expr

Returns:

int

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