org.basex.query.xpath.expr
Class Cmp

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

Direct Known Subclasses:

Equality, Relational

public abstract class Cmp
extends Arr

Abstract Compare Expression.

Author:

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

Field Summary

Comp	type Expression Type.

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

expr

Constructor Summary

Cmp(Expr e1, Expr e2)
Constructor.

Method Summary

Expr	comp(XPContext ctx) Optimizes the expression.
Bln	eval(XPContext ctx) Evaluates the expression with the specified context set.
void	plan(Serializer ser) Recursively sends the abstract syntax of this expression to the specified serializer.
boolean	standard() Checks if this expression has a location path and Item as arguments.
java.lang.String	toString()

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

sameAs, usesPos, usesSize

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

indexEquivalent, indexSizes, returnedValue

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

type

public Comp type

Expression Type.

Constructor Detail

Cmp

public Cmp(Expr e1,
           Expr e2)

Constructor.

Parameters:

e1 - first expression

e2 - second expression to compare with first

Method Detail

comp

public Expr comp(XPContext ctx)
          throws QueryException

Description copied from class: Expr

Optimizes the expression.

Overrides:

comp in class Arr

Parameters:

ctx - expression context

Returns:

optimized Expression

Throws:

QueryException - evaluation exception

eval

public final 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

standard

public final boolean standard()

Checks if this expression has a location path and Item as arguments.

Returns:

result of check

toString

public final java.lang.String toString()

Specified by:

toString in class ExprInfo

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 Arr

Parameters:

ser - serializer

Throws:

java.io.IOException - exception