ch.ethz.mxquery.opt.expr
Class ValueLiteral

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

All Implemented Interfaces:

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

public final class ValueLiteral
extends Literal

A value literal is a wrapper for any kind of iterator. The result is materialized with Tokens and returned

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

ValueLiteral(XDMIterator iter)

Method Summary

void	evaluate() Evaluates and materializes the result
int	evaluate(int dependency) Evaluates the literator up to a specific level.
void	evaluateExpectOneValue() Evaluates but expects only on atomic value
java.lang.String	getColumnName() Returns a name of a childIterator - if the variable depends on one directly;
Token	getToken() Normally used together with evaluateExpectOneValue().
Token[]	getValues() Returns all tokens from the evaluation.
int	reset()
int	reset(int level) Resets the logical unit up to a certain degree on variable dependency
void	setColumnName(java.lang.String name)

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

clone, getIter, traverse

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

ValueLiteral

public ValueLiteral(XDMIterator iter)

Method Detail

evaluate

public void evaluate()
              throws MXQueryException

Evaluates and materializes the result

Throws:

MXQueryException

evaluateExpectOneValue

public void evaluateExpectOneValue()
                            throws MXQueryException

Evaluates but expects only on atomic value

Throws:

MXQueryException

evaluate

public int evaluate(int dependency)

Description copied from class: Literal

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

Overrides:

evaluate in class Literal

Parameters:

dependency - Up to this dependency level the unit is evaluated

Returns:

false, true or unknown

getValues

public Token[] getValues()

Returns all tokens from the evaluation.

Returns:

all XDM tokens generated by the evaluation

getToken

public Token getToken()

Normally used together with evaluateExpectOneValue(). Returns the evaluated materialized token

Returns:

the generated token

getColumnName

public java.lang.String getColumnName()

Returns a name of a childIterator - if the variable depends on one directly;

Returns:

the step name if present

setColumnName

public void setColumnName(java.lang.String name)

reset

public 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

reset

public int reset()