ch.ethz.mxquery.opt.expr
Class Term

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

All Implemented Interfaces:

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

Direct Known Subclasses:

CTerm, DTerm

public abstract class Term
extends LogicalUnit

A term for the optimization. A term consits again of logical units, which can be in turn again terms, literal etc.

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

Term()

Method Summary

void	add(LogicalUnit unit) Adds a new logical unit to the term
void	addAll(Term term) Adds a list of terms into this term.
java.lang.Object	clone() Creates a copy.
abstract int	evaluate(int level) Evaluates the logical unit until a certain degree on variable dependency and returns if the result is false, true or unknown
LogicalUnit	get(int i)
abstract int	reset(int level) Resets the logical unit up to a certain degree on variable dependency
int	size() Returns the number of logical units in this term
void	sort() Sorts the result list according to the used variables
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, setDependency, setIndexable

Methods inherited from class java.lang.Object

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

Constructor Detail

Term

public Term()

Method Detail

get

public LogicalUnit get(int i)

addAll

public void addAll(Term term)

Adds a list of terms into this term.

Parameters:

term -

size

public int size()

Returns the number of logical units in this term

Returns:

the number of logical units

add

public void add(LogicalUnit unit)

Adds a new logical unit to the term

Parameters:

unit -

sort

public void sort()

Sorts the result list according to the used variables

evaluate

public abstract int evaluate(int level)
                      throws MXQueryException

Description copied from class: LogicalUnit

Evaluates the logical unit until a certain degree on variable dependency and returns if the result is false, true or unknown

Specified by:

evaluate in class LogicalUnit

Parameters:

level - Up to this dependency level the unit is evaluated

Returns:

false, true or unknown

Throws:

MXQueryException

reset

public abstract int reset(int level)

Description copied from class: LogicalUnit

Resets the logical unit up to a certain degree on variable dependency

Overrides:

reset in class LogicalUnit

Returns:

UNKNOWN, TRUE or FALSE

clone

public java.lang.Object clone()

Creates a copy.

traverse

public KXmlSerializer traverse(KXmlSerializer serializer)

Specified by:

traverse in interface Traversable

Overrides:

traverse in class LogicalUnit