org.basex.query.expr
Class Union

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

public final class Union
extends Arr

Union expression.

Author:

Workgroup DBIS, University of Konstanz 2005-09, 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.Arr

expr

Constructor Summary

Union(Expr[] e)
Constructor.

Method Summary

Expr	comp(QueryContext ctx) Optimizes and compiles the expression.
NodeIter	iter(QueryContext ctx) Evaluates the expression and returns an iterator on the resulting items.
java.lang.String	toString()

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

duplicates, indexEquivalent, plan, removable, remove, uses

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

addText, atomic, checkCtx, checkDbl, checkItr, e, ebv, i, indexAccessible, returned, sameAs, size, test

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

Constructor Detail

Union

public Union(Expr[] e)

Constructor.

Parameters:

e - expression list

Method Detail

comp

public Expr comp(QueryContext ctx)
          throws QueryException

Description copied from class: Expr

Optimizes and compiles the expression.

Overrides:

comp in class Arr

Parameters:

ctx - query context

Returns:

optimized Expression

Throws:

QueryException - query exception

iter

public NodeIter 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.

Overrides:

iter in class Expr

Parameters:

ctx - query context

Returns:

resulting item

Throws:

QueryException - query exception

toString

public java.lang.String toString()

Specified by:

toString in class ExprInfo