org.basex.query.xpath.func
Class Distinct

java.lang.Object
  org.basex.query.ExprInfo
      org.basex.query.xpath.expr.Expr
          org.basex.query.xpath.func.Func
              org.basex.query.xpath.func.Distinct

public final class Distinct
extends Func

Constructor for the implementation specific distinct() function.

Author:

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

Field Summary

static java.lang.String

NAME Name of function.

Fields inherited from class org.basex.query.xpath.func.Func

desc

Constructor Summary

Distinct(Expr[] arg)
Function Constructor.

Method Summary

boolean	checkArguments() Checks validity/number of arguments.
Nod	eval(XPContext ctx) Evaluates the expression with the specified context set.

Methods inherited from class org.basex.query.xpath.func.Func

comp, evalArgs, plan, toString, usesPos, usesSize

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

indexEquivalent, indexSizes, 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

NAME

public static final java.lang.String NAME

Name of function.

Constructor Detail

Distinct

public Distinct(Expr[] arg)

Function Constructor.

Parameters:

arg - expression array

Method Detail

eval

public Nod 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

checkArguments

public boolean checkArguments()

Description copied from class: Func

Checks validity/number of arguments.

Specified by:

checkArguments in class Func

Returns:

result of comparison