// Copyright (C) 2003, 2005 Daisuke Arai <darai@users.sourceforge.jp>
// 
// This program is part of Protra.
//
// Protra is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
// 
// $Id: ContinueStatementNode.cs,v 1.3 2007-12-27 08:34:39 panacoran Exp $

using System;

namespace Protra.Lib.Lang
{
	/// <summary>
	/// continue文のノードを表すクラスです。
	/// </summary>
	public class ContinueStatementNode : Node
	{
		/// <summary>
		/// 文脈を解析します。
		/// </summary>
		/// <exception cref="Protra.Lib.Lang.ParseException">
		/// 文脈にエラーがある場合にthrowされます。
		/// </exception>
		/// <param name="context">コンテキスト</param>
		public override void Parse(Context context)
		{
			this.ContextToken = (ContextToken)context.Current;

			context.MoveNext();
			ContextToken ct = (ContextToken)context.Current;
			string token = ct.ToString();
			if(token != ";")
				throw new ParseException("; expected", this.ContextToken);
		}

		/// <summary>
		/// 構文木を簡略化します。
		/// </summary>
		/// <returns>簡略化されたノード</returns>
		public override Node Simplify()
		{
			return this;
		}

		/// <summary>
		/// プログラムを実行します。
		/// </summary>
		/// <exception cref="Protra.Lib.Lang.RuntimeException">
		/// プログラム実行中にエラーが発生した場合にthrowされます。
		/// </exception>
		/// <exception cref="Protra.Lib.Lang.ContinueStatementExecutedException">
		/// 必ずthrowされます。
		/// </exception>
		/// <param name="resource">リソース</param>
		/// <param name="at">@作用素の値</param>
		/// <returns>実行結果</returns>
		public override Value Execute(Resource resource, int at)
		{
			throw new ContinueStatementExecutedException();
		}
	}

	/// <summary>
	/// ContinueStatementNode.Executeが呼ばれたときにthrowされる例外です。
	/// </summary>
	public class ContinueStatementExecutedException : Exception {}
}
