story.dbcore.parameters
Class BooleanReturnParameter
java.lang.Object
story.dbcore.parameters.Parameter
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.
Methods inherited from class java.lang.Object |
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
BooleanReturnParameter
public BooleanReturnParameter()
Copyright © 2011 David K. Elson. All Rights Reserved.