org.basex.query.ft
Class FTPos

java.lang.Object
  org.basex.query.ExprInfo
      org.basex.query.expr.Expr
          org.basex.query.ft.FTExpr
              org.basex.query.ft.FTPos

public final class FTPos
extends FTExpr

FTSelect expression.

Author:

Workgroup DBIS, University of Konstanz 2005-09, ISC License, Christian Gruen

Nested Class Summary

static class

FTPos.FTUnit Units.

Field Summary

boolean	content Entire content flag.
boolean	different Different flag.
Expr[]	dist Distance occurrences.
FTPos.FTUnit	dunit Distance unit.
boolean	end End flag.
FTTokenizer	ft Input token.
boolean	ordered Ordered flag.
boolean	same Same flag.
FTPos.FTUnit	sdunit Same/different unit.
boolean	start Start flag.
TokenList	term Term list.
Expr	weight Weight.
Expr	window Window.
FTPos.FTUnit	wunit Window unit.

Fields inherited from class org.basex.query.ft.FTExpr

expr

Constructor Summary

FTPos(FTExpr e)
Constructor.

Method Summary

FTExpr	comp(QueryContext ctx) Optimizes and compiles the expression.
void	indexAccessible(QueryContext ctx, IndexContext ic) Checks if an index can be used for query evaluation.
FTExpr	indexEquivalent(QueryContext ctx, IndexContext ic) Returns an equivalent expression which accesses an index structure.
FTNodeIter	iter(QueryContext ctx) Evaluates the expression and returns an iterator on the resulting items.
void	plan(Serializer ser) Recursively sends the abstract syntax of this expression to the specified serializer.
boolean	standard() Returns true if no position filters are defined.
java.lang.String	toString()

Methods inherited from class org.basex.query.ft.FTExpr

color, remove, returned, uses

Methods inherited from class org.basex.query.expr.Expr

addText, atomic, checkCtx, checkDbl, checkItr, duplicates, e, ebv, i, removable, sameAs, size, test

Methods inherited from class org.basex.query.ExprInfo

info, name

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

ordered

public boolean ordered

Ordered flag.

start

public boolean start

Start flag.

end

public boolean end

End flag.

content

public boolean content

Entire content flag.

same

public boolean same

Same flag.

different

public boolean different

Different flag.

dunit

public FTPos.FTUnit dunit

Distance unit.

wunit

public FTPos.FTUnit wunit

Window unit.

sdunit

public FTPos.FTUnit sdunit

Same/different unit.

term

public TokenList term

Term list.

ft

public FTTokenizer ft

Input token.

window

public Expr window

Window.

dist

public Expr[] dist

Distance occurrences.

weight

public Expr weight

Weight.

Constructor Detail

FTPos

public FTPos(FTExpr e)

Constructor.

Parameters:

e - expression

Method Detail

comp

public FTExpr comp(QueryContext ctx)
            throws QueryException

Description copied from class: Expr

Optimizes and compiles the expression.

Overrides:

comp in class FTExpr

Parameters:

ctx - query context

Returns:

optimized Expression

Throws:

QueryException - evaluation exception

iter

public FTNodeIter iter(QueryContext ctx)
                throws QueryException

Description copied from class: Expr

Evaluates the expression and returns an iterator on the resulting items. If this method is not overwritten, Expr.atomic(org.basex.query.QueryContext) must be implemented.

Specified by:

iter in class FTExpr

Parameters:

ctx - query context

Returns:

resulting item

Throws:

QueryException - evaluation exception

standard

public boolean standard()

Returns true if no position filters are defined.

Returns:

result of check

indexAccessible

public void indexAccessible(QueryContext ctx,
                            IndexContext ic)
                     throws QueryException

Description copied from class: Expr

Checks if an index can be used for query evaluation.

Overrides:

indexAccessible in class Expr

Parameters:

ctx - query context

ic - index context

Throws:

QueryException - Exception

indexEquivalent

public FTExpr indexEquivalent(QueryContext ctx,
                              IndexContext ic)
                       throws QueryException

Description copied from class: Expr

Returns an equivalent expression which accesses an index structure. Must be called if Expr.indexAccessible(org.basex.query.QueryContext, org.basex.query.IndexContext) is implemented for an expression.

Overrides:

indexEquivalent in class FTExpr

Parameters:

ctx - query context

ic - index context

Returns:

Equivalent index-expression or null

Throws:

QueryException - Exception

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 FTExpr

Parameters:

ser - serializer

Throws:

java.io.IOException - exception

toString

public java.lang.String toString()

Specified by:

toString in class ExprInfo