story.dbcore.parameters
Class BooleanReturnParameter

java.lang.Object
  extended by story.dbcore.parameters.Parameter
      extended by story.dbcore.parameters.BooleanReturnParameter
Direct Known Subclasses:
AndParameter, AttComparedToAttParameter, AttComparedToConstParameter, BooleanEvalParameter, IsInstanceNodeParameter, IsInstancingParameter, NegationParameter, NodesRelatedParameter, NumRelatedEqParameter, OrBooleanParameter, ThereExistsParameter

public abstract class BooleanReturnParameter
extends Parameter

A class with no functionality that serves to organize the Parameter hierarchy by grouping together those Parameters that evaluate to True or False.

Only parameters of these types can be evaluated in a true() or false() command in a ParameterSet and filter query results on the results of their evaluations. For example, true(node.attribute==value).

Parameters extending this class are also called "filter" parameters, in that they do not match anything, but filter existing matches. Note the difference between BooleanMatchParameter and BooleanEvalParameter -- one matches an argued Boolean and does not extend this class; the other tests a stored Boolean and does extend this class.

Another common feature among BooleanReturnParameters is that they do not support outreferences, i.e., unlike MatchParameters, they do not store any results in the reference SymbolTable for possible use by future Parameters.


Constructor Summary
BooleanReturnParameter()
           
 
Method Summary
 
Methods inherited from class story.dbcore.parameters.Parameter
assumedNodes, makeClone, makeCopy, referenceRequirements, render, specificRender
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

BooleanReturnParameter

public BooleanReturnParameter()


Copyright © 2011 David K. Elson. All Rights Reserved.