Entity mapping language implementation using bsn-goldparser with CodeDom

// bsn GoldParser .NET Engine
// --------------------------
// 
// Copyright 2009, 2010 by Ars�ne von Wyss - avw@gmx.ch
// 
// Development has been supported by Sirius Technologies AG, Basel
// 
// Source:
// 
// https://bsn-goldparser.googlecode.com/hg/
// 
// License:
// 
// The library is distributed under the GNU Lesser General Public License:
// http://www.gnu.org/licenses/lgpl.html
// 
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 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 Lesser General Public License for more details.
// 
// You should have received a copy of the GNU Lesser General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
// 
using System;
using System.Collections.Generic;

namespace bsn.GoldParser.Semantic {
	/// <summary>
	/// This attribute is used to define specific trim rules.
	/// </summary>
	/// <seealso cref="TerminalAttribute"/>
	/// <seealso cref="RuleAttribute"/>
	[AttributeUsage(AttributeTargets.Assembly|AttributeTargets.Class, AllowMultiple=true, Inherited=false)]
	public sealed class RuleTrimAttribute: RuleAttributeBase {
		private delegate ArgumentException ArgumentExceptionDelegate();

		private static ArgumentException SymbolNotFoundException() {
			return new ArgumentException("The specified symbol is not part of the rule", "trimSymbol");
		}

		private static ArgumentOutOfRangeException SymbolIndexOutOfRangeException() {
			return new ArgumentOutOfRangeException("trimSymbolIndex");
		}

		private readonly int trimSymbolIndex;
		private Type semanticTokenType;

		/// <summary>
		/// Initializes a new instance of the <see cref="RuleTrimAttribute"/> class.
		/// </summary>
		/// <param name="rule">The rule.</param>
		/// <param name="trimSymbol">The trim symbol name.</param>
		public RuleTrimAttribute(string rule, string trimSymbol): this(rule, -1, trimSymbol, SymbolNotFoundException) {}

		/// <summary>
		/// Initializes a new instance of the <see cref="RuleTrimAttribute"/> class.
		/// </summary>
		/// <param name="rule">The rule.</param>
		/// <param name="trimSymbolIndex">Index of the trim symbol.</param>
		public RuleTrimAttribute(string rule, int trimSymbolIndex): this(rule, trimSymbolIndex, string.Empty, SymbolIndexOutOfRangeException) {}

		private RuleTrimAttribute(string rule, int trimSymbolIndex, string trimSymbol, ArgumentExceptionDelegate notFoundException): base(rule) {
			if (trimSymbol == null) {
				throw new ArgumentNullException("trimSymbol");
			}
			int ruleHandleCount = 0;
			using (IEnumerator<string> ruleHandleEnumerator = RuleDeclarationParser.GetRuleHandleNames(ParsedRule).GetEnumerator()) {
				while (ruleHandleEnumerator.MoveNext()) {
					if (trimSymbol.Equals(ruleHandleEnumerator.Current)) {
						if (trimSymbolIndex >= 0) {
							throw new ArgumentException("The given symbol is ambigious in this rule", "trimSymbol");
						}
						trimSymbolIndex = ruleHandleCount;
					}
					ruleHandleCount++;
				}
			}
			if ((trimSymbolIndex < 0) || (trimSymbolIndex >= ruleHandleCount)) {
				throw notFoundException();
			}
			this.trimSymbolIndex = trimSymbolIndex;
		}

		/// <summary>
		/// Gets or sets the type of the semantic token for which the trim rule has been defined.
		/// </summary>
		/// <value>The type of the semantic token.</value>
		public Type SemanticTokenType {
			get {
				return semanticTokenType;
			}
			set {
				semanticTokenType = value;
			}
		}

		/// <summary>
		/// Gets the handle index of the trim symbol.
		/// </summary>
		/// <value>The handle index of the trim symbol.</value>
		public int TrimSymbolIndex {
			get {
				return trimSymbolIndex;
			}
		}
	}
}