gee/iterator.vala

   1 /* iterator.vala
   2  *
   3  * Copyright (C) 2007-2008  Jürg Billeter
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
  18  *
  19  * Author:
  20  *      Jürg Billeter <j@bitron.ch>
  21  */
  22
  23 /**
  24  * Implemented by classes that support a simple iteration over instances of the
  25  * collection.
  26  */
  27 public abstract class Vala.Iterator<G> {
  28         /**
  29          * Advances to the next element in the iteration.
  30          *
  31          * @return true if the iterator has a next element
  32          */
  33         public abstract bool next ();
  34
  35         /**
  36          * Checks whether there is a next element in the iteration.
  37          *
  38          * @return ``true`` if the iterator has a next element
  39          */
  40         public abstract bool has_next ();
  41
  42         /**
  43          * Returns the current element in the iteration.
  44          *
  45          * @return the current element in the iteration
  46          */
  47         public abstract G? get ();
  48
  49         /**
  50          * Removes the current element in the iteration. The cursor is set in an
  51          * in-between state. Both {@link get} and {@link remove} will fail until
  52          * the next move of the cursor (calling {@link next}).
  53          */
  54         public abstract void remove ();
  55
  56         /**
  57          * Determines wheather the call to {@link get} is legal. It is false at the
  58          * beginning and after {@link remove} call and true otherwise.
  59          */
  60         public abstract bool valid { get; }
  61 }
  62