package languages;

import java_cup.runtime.Symbol;

/**
 * TODO Add documentation here.
 *
 * @author Benedikt Meurer
 * @version $Id$
 */
public final class LanguageSymbol extends Symbol {
  //
  // Attributes
  //
  
  /**
   * The name of the symbol, i.e. <code>"START"</code> for the start symbol.
   * 
   * @see #getName()
   */
  private String name;
  
  
  
  //
  // Constructors
  //
  
  /**
   * Allocates a new <code>LanguageSymbol</code> with the specified
   * <code>name</code> and the specified symbol <code>id</code>.
   * 
   * The <code>left</code> and <code>right</code> values specify
   * character offsets in the source stream. They may be <code>-1</code>
   * if the offsets aren't available.
   * 
   * The <code>value</code> is the value associated with this symbol,
   * for example, the value assigned to a symbol by the lexer. May be
   * <code>null</code> if no value is available.
   * 
   * @param name the name of the symbol.
   * @param id the unique identifier of the symbol.
   * @param left the left position in the source, or <code>-1</code>.
   * @param right the right position in the source, or <code>-1</code>.
   * @param value the value assigned to the symbol, or <code>null</code>.
   * 
   * @see #getLeft()
   * @see #getRight()
   * @see #getName()
   */
  LanguageSymbol(String name, int id, int left, int right, Object value) {
    super(id, left, right, value);
    this.name = name;
  }
  
  /**
   * Special constructor that allocates a new <code>LanguageSymbol</code>
   * with the given <code>name</code> and symbol <code>id</code>, and sets
   * the parser private state variable to the specified <code>state</code>.
   * 
   * This method should only be used by the <code>startSymbol()</code>
   * method of the {@link LanguageSymbolFactory} class.
   * 
   * @param name the name of the symbol.
   * @param id the unique identifier of the symbol.
   * @param state the initial parse state.
   * 
   * @see LanguageSymbolFactory#startSymbol(String, int, int)
   * @see Symbol#parse_state
   */
  LanguageSymbol(String name, int id, int state) {
    super(id, state);
    this.name = name;
  }
  

  
  //
  // Accessors
  //

  /**
   * Returns the unique identifier of this symbol.
   * 
   * @return the unique identifier of this symbol.
   */
  public int getId() {
    return this.sym;
  }
  
  /**
   * Returns the left position of the symbol in the source stream
   * or <code>-1</code> if the left position is not known.
   *  
   * @return the left position of the symbol, or <code>-1</code>.
   * 
   * @see #getRight()
   */
  public int getLeft() {
    return this.left;
  }
  
  /**
   * Returns the right position of the symbol in the source stream
   * or <code>-1</code> if the right position is not known.
   * 
   * @return the right position of the symbol, or <code>-1</code>.
   * 
   * @see #getLeft()
   */
  public int getRight() {
    return this.right;
  }
  
  /**
   * Returns the name of the symbol, i.e. <code>"START"</code> in case of
   * the start symbol of the parser.
   * 
   * @return the name of the symbol.
   */
  public String getName() {
    return this.name;
  }
  
  
  
  //
  // Overwritten methods
  //
  
  /**
   * Returns the string representation for this <code>LanguageSymbol</code>,
   * which is simply the name of the symbol.
   *
   * @return the string representation for this symbol.
   * 
   * @see Object#toString()
   */
  @Override
  public String toString() {
    return this.name;
  }
}