// file:    Scaler.java
// author:  Robert M. Keller
// purpose: Example of a Function1 object

/**
 * A Scaler is a Function1 object that can be used to scale a list of
 * Numbers by a scale factor.  If both the scale factor and the function
 * argument are Integer or Long, a Long will be returned.  Otherwise a
 * Double will be returned.
 */

class Scaler implements Function1
{
private Number factor;

/**
 * Create a Scaler with a specific scale factor.
 * @param _factor the factor to be used
 */

Scaler(Number _factor)
  {
  factor = _factor;
  }


/**
 * Apply this Scaler object to an Object x, which should be a Number.
 * If x is not a number, a ClassCastException will be thrown.
 *
 * @param x the Object to which this function is applied
 * @return a Double containing this Scaler's factor times the argument's value
 */

public Object apply(Object x)
  {
  return Multiplier.multiply(factor, x);
  }
}