/*  Word.java */

/**  Implements a Word, which is a Hashable String.
 *   Words are automatically stored in lowercase.
 */

import Supporting.*;

public class Word implements Hashable {

  /** Constructs a new word.
   * @param v in lower case will be the string value of the word.
   */
  public Word( String v ) {
    key = v.toLowerCase();
  }

  /** Returns the String value of this word.
   * @returns a String value of this word.
   */
  public String toString() {
    return key;
  }

  /** Get the length. 
   * @return the length of the word.
   */
  public int length() {
    return key.length();
  }

  /** Returns the hashed value of this String as an integer.
   *          Hashed value in the range: [0 ... tableSize-1]
   */
  public int hash( int tableSize ) {
    // NOTE : This is a terrible hash function.
    if( key.length() == 0 ) return 0;

    int c = key.charAt(0) - 'a';
    if( c < 0 ) {
      c = -c;
    }

    return c;
  }

  /** An alternate hash function (the String hash function in Java). 
   */
  public int hash1( int tableSize ) {
    int hashVal = key.hashCode();
    if (hashVal < 0) {
      hashVal = -hashVal;
    }
    return hashVal % tableSize;
  }

  /** An alternate hash function (from lecture). 
   */
  public int hash2( int tableSize ) {
    int hashVal = 0;
    for (int i = 0; i < key.length(); i++) {
      hashVal = (128 * hashVal + key.charAt(i)) % tableSize;
    }
    return hashVal;
  }

  /** Determines whether two words are equal.
   * @returns returns true <==> string values of things and o are equal.
   * @exception ClassCastException if o is not a Word.
   */
  public boolean equals( Object o ) {
    Word wo = (Word)o;

    return key.equals(wo.key);
  }

  private String key;
}