// TextMeter.java

import java.util.Map;

/**
 * The TextMeter interface is implemented by parser plug-ins that
 * measure statistical properties of the parsed text. Tokens are
 * expected to be presented in the order they are found by the parser,
 * although for many measurements this is not critical.
 *
 * @author Fredrik Kilander for ID1006
 */
public interface TextMeter {

  /**
   * Presents a word token to the TextMeter.
   *
   * @param wt The WordToken to add to the measurement.
   */
  public void add (WordToken wt);

  /**
   * Presents a punctuation token to the TextMeter.
   *
   * @param wt The PunctToken to add to the measurement.
   */
  public void add (PunctToken pt);

  /**
   * Returns a property map of the current measurement. The keys and
   * their values are defined by the implementation.
   *
   * @return The current properties of the current measurement.
   */
  public Map<String,String> properties ();

  /**
   * Retrieves a single property from the current measurement. If no
   * such property exists, null should be returned.
   *
   * @param key The key of the requested property.
   * @return The value of the requested property.
   */
  public String getProperty (String key);

} // interface TextMeter