org.basex.query.expr
Class CmpR

java.lang.Object
  org.basex.query.ExprInfo
      org.basex.query.expr.Expr
          org.basex.query.expr.Single
              org.basex.query.expr.CmpR

public final class CmpR
extends Single

Range comparison expression.

Author:

Workgroup DBIS, University of Konstanz 2005-10, ISC License, Christian Gruen

Nested Class Summary

Nested classes/interfaces inherited from class org.basex.query.expr.Expr

Expr.Use

Field Summary

Fields inherited from class org.basex.query.expr.Single

expr

Method Summary

Item	atomic(QueryContext ctx) Evaluates the expression and returns the resulting item or a null reference.
boolean	indexAccessible(IndexContext ic) Checks if an index can be used for query evaluation.
AxisPath	indexEquivalent(IndexContext ic) Returns an equivalent expression which accesses an index structure.
Return	returned(QueryContext ctx) Indicates the return type of an expression.
String	toString()

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

comp, plan, remove, uses

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

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

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

Method Detail

atomic

public Item atomic(QueryContext ctx)
            throws QueryException

Description copied from class: Expr

Evaluates the expression and returns the resulting item or a null reference. If this method is not overwritten, Expr.iter(org.basex.query.QueryContext) must be implemented.

Overrides:

atomic in class Expr

Parameters:

ctx - query context

Returns:

iterator

Throws:

QueryException - query exception

indexAccessible

public boolean indexAccessible(IndexContext ic)

Description copied from class: Expr

Checks if an index can be used for query evaluation.

Overrides:

indexAccessible in class Expr

Parameters:

ic - index context

Returns:

true if an index can be used

indexEquivalent

public AxisPath indexEquivalent(IndexContext ic)

Description copied from class: Expr

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

Overrides:

indexEquivalent in class Expr

Parameters:

ic - index context

Returns:

Equivalent index-expression or null

returned

public Return returned(QueryContext ctx)

Description copied from class: Expr

Indicates the return type of an expression. Called by the compiler to check if expressions can be reformulated. null is returned by default.

Overrides:

returned in class Expr

Parameters:

ctx - query context

Returns:

result of check

toString

public String toString()

Specified by:

toString in class ExprInfo