package net.sourceforge.phpdt.internal.compiler.ast;

import java.util.List;

/**
 * It will be the mother of our own ast tree for php just like the ast tree of Eclipse.
 * @author Matthieu Casanova
 */
public abstract class AstNode {

  /** Starting and ending position of the node in the sources. */
  public int sourceStart, sourceEnd;

  /**
   * Create a node giving starting and ending offset
   * @param sourceStart starting offset
   * @param sourceEnd ending offset
   */
  public AstNode(final int sourceStart, final int sourceEnd) {
    this.sourceStart = sourceStart;
    this.sourceEnd = sourceEnd;
  }

  /**
   * Add some tabulations.
   * @param tab the number of tabulations
   * @return a String containing some spaces
   */
  public static String tabString(final int tab) {
    final StringBuffer s = new StringBuffer(2 * tab);
    for (int i = tab; i > 0; i--) {
      s.append("  "); //$NON-NLS-1$
    }
    return s.toString();
  }

  /**
   * Return the object into String.
   * It should be overriden
   * @return a String
   */
  public String toString() {
    return "****" + super.toString() + "****";  //$NON-NLS-2$ //$NON-NLS-1$
  }

  /**
   * Return the object into String.
   * @param tab how many tabs (not used here
   * @return a String
   */
  public abstract String toString(int tab);

  /**
   * Get the variables from outside (parameters, globals ...)
   * @return the variables from outside
   */
  public abstract List getOutsideVariable();

  /**
   * get the modified variables.
   * @return the variables modified
   */
  public abstract List getModifiedVariable();

  /**
   * Get the variables used.
   * @return the variables used
   */
  public abstract List getUsedVariable();
}