ch.ethz.mxquery.opt.expr
Class Literal

java.lang.Object
  ch.ethz.mxquery.opt.expr.LogicalUnit
      ch.ethz.mxquery.opt.expr.Literal

All Implemented Interfaces:

Traversable, java.lang.Cloneable, java.lang.Comparable

Direct Known Subclasses:

CompareLiteral, ValueLiteral

public class Literal
extends LogicalUnit

A literal in this optimizer has always exactly one iterator on which it depends. So logical iterators are split in this optimizer tree

Field Summary

Fields inherited from class ch.ethz.mxquery.opt.expr.LogicalUnit

DEPENDENCY_END, DEPENDENCY_NO, DEPENDENCY_START, DEPENDENCY_STARTEND, INDEX_IMPOSSIBLE, INDEX_POSSIBLE, INDEX_RECOMMEND, RESET, RESULT_FALSE, RESULT_TRUE, RESULT_UNKNOWN

Constructor Summary

Literal(XDMIterator iter)

Method Summary

java.lang.Object	clone() Clones the Literal but the underlying Iterator isn't cloned
int	evaluate(int level) Evaluates the literator up to a specific level.
XDMIterator	getIter()
KXmlSerializer	traverse(KXmlSerializer serializer)

Methods inherited from class ch.ethz.mxquery.opt.expr.LogicalUnit

addDependency, compareTo, getDependency, getDependencyName, getDependencyNb, getResult, isDependendOnEnd, isDependendOnStart, isIndexable, isLowerDependency, isLowerOrEqualDependency, reset, setDependency, setIndexable

Methods inherited from class java.lang.Object

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

Constructor Detail

Literal

public Literal(XDMIterator iter)

Method Detail

getIter

public XDMIterator getIter()

evaluate

public int evaluate(int level)
             throws MXQueryException

Evaluates the literator up to a specific level. The level distinguish how many dependencies should be evalueted

Specified by:

evaluate in class LogicalUnit

Parameters:

level - Up to this dependency level the unit is evaluated

Returns:

false, true or unknown

Throws:

MXQueryException

clone

public java.lang.Object clone()

Clones the Literal but the underlying Iterator isn't cloned

traverse

public KXmlSerializer traverse(KXmlSerializer serializer)

Specified by:

traverse in interface Traversable

Overrides:

traverse in class LogicalUnit