RuleVariable.java

import java.util.*;
import java.awt.* ;

public class RuleVariable extends Variable {

  public RuleVariable(String Name) {
    super(Name);
    clauseRefs = new Vector();
  }

  void setValue(String val) {
    value = val;
    updateClauses();
  }

  // prompt a user to provide a value for a variable during inferencing
  String askUser() {

    String answer = RuleApplet.waitForAnswer(promptText, getLabels()) ; // show dialog

    RuleBase.appendText("\n  !!! Looking for " + name + ". User entered: " + answer) ;
    setValue(answer) ; // need to set value from textField here
    return value ;
  }

  Vector clauseRefs ;   // clauses which refer to this var
  void addClauseRef(Clause ref) {
    clauseRefs.addElement(ref) ;
  }

  void updateClauses() {

    Enumeration enume = clauseRefs.elements() ;
    while(enume.hasMoreElements())
     ((Clause)enume.nextElement()).check() ; // retest the truth condition
  }

  String promptText ;  // used to prompt user for value
  String ruleName ;      // if value is inferred, null = user provided
  void setRuleName(String rname) {
    ruleName = rname;
  }
  void setPromptText(String text) {
    promptText = text;
  }

  // these methods are not used in rule variables
  public void computeStatistics(String inValue){} ;
  public int normalize(String inValue, float[] outArray, int inx) {return inx;}

}