org.basex.query.xpath.expr
Class Arr

java.lang.Object
  org.basex.query.ExprInfo
      org.basex.query.xpath.expr.Expr
          org.basex.query.xpath.expr.Arr

Direct Known Subclasses:

And, Clc, Cmp, FTContains, FTContainsNS, InterSect, Or, Path, Union

public abstract class Arr
extends Expr

Abstract array expression.

Author:

Workgroup DBIS, University of Konstanz 2005-08, ISC License, Christian Gruen

Field Summary

Expr[]

expr Expression list.

Method Summary

Expr	comp(XPContext ctx) Optimizes the expression.
void	plan(Serializer ser) Recursively sends the abstract syntax of this expression to the specified serializer.
boolean	sameAs(Expr cmp) Checks current and specified expression for equivalence.
boolean	usesPos() Checks whether this Expression (or its children) make use of the position parameter.
boolean	usesSize() Checks whether this Expression (or its children) make use of the setsize parameter.

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

eval, indexEquivalent, indexSizes, returnedValue

Methods inherited from class org.basex.query.ExprInfo

color, info, name, toString

Methods inherited from class java.lang.Object

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

Field Detail

expr

public Expr[] expr

Expression list.

Method Detail

comp

public Expr comp(XPContext ctx)
          throws QueryException

Description copied from class: Expr

Optimizes the expression.

Specified by:

comp in class Expr

Parameters:

ctx - expression context

Returns:

optimized Expression

Throws:

QueryException - evaluation exception

usesPos

public final boolean usesPos()

Description copied from class: Expr

Checks whether this Expression (or its children) make use of the position parameter. If not this allows some nice optimizations.

Specified by:

usesPos in class Expr

Returns:

whether position is used

usesSize

public final boolean usesSize()

Description copied from class: Expr

Checks whether this Expression (or its children) make use of the setsize parameter. If not this allows early predicate evaluation.

Specified by:

usesSize in class Expr

Returns:

whether setsize is used

sameAs

public boolean sameAs(Expr cmp)

Description copied from class: Expr

Checks current and specified expression for equivalence.

Overrides:

sameAs in class Expr

Parameters:

cmp - expression to be compared

Returns:

result of check

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.

Specified by:

plan in class ExprInfo

Parameters:

ser - serializer

Throws:

java.io.IOException - exception