AtomicExpression.java

Go to the documentation of this file.

package aud.example.expr;
 
public abstract class AtomicExpression {
  protected ExpressionTree node_ = null;
 
  public boolean isOperator() { return !isTerminal(); }
  public boolean isTerminal() { return node_.isLeaf(); }
 
  public enum Type {
    OpPlus, OpMinus, OpUnaryMinus, OpTimes, OpDivide, OpPower,
    TNumber, TSymbol
  }
  public abstract Type getType();
 
  @Override public AtomicExpression clone() {
    // Note that this should be an abstract method!
    //
    // The implementation that throws an exception frees us from
    // defining clone(), e.g., in the new Power class (expect less
    // suprises.)
    //
    // Similarly, AtomicExpression should better implement
    // Cloneable; but then we always had to take care of possible
    // exception (CloneNotSupportedException).
    throw new RuntimeException("You didn't overwrite clone()!");
  }
 
  public abstract double getValue();
}