source: trunk/sources/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory-5.5.0/PatternMatching/Choice.cs @ 11807

// Copyright (c) 2011-2013 AlphaSierraPapa for the SharpDevelop Team
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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using System;
using System.Collections;
using System.Collections.Generic;

namespace ICSharpCode.NRefactory.PatternMatching
{
  /// <summary>
  /// Matches one of several alternatives.
  /// </summary>
  public class Choice : Pattern, IEnumerable<INode>
  {
    readonly List<INode> alternatives = new List<INode>();
    
    public void Add(string name, INode alternative)
    {
      if (alternative == null)
        throw new ArgumentNullException("alternative");
      alternatives.Add(new NamedNode(name, alternative));
    }
    
    public void Add(INode alternative)
    {
      if (alternative == null)
        throw new ArgumentNullException("alternative");
      alternatives.Add(alternative);
    }
    
    public override bool DoMatch(INode other, Match match)
    {
      var checkPoint = match.CheckPoint();
      foreach (INode alt in alternatives) {
        if (alt.DoMatch(other, match))
          return true;
        else
          match.RestoreCheckPoint(checkPoint);
      }
      return false;
    }
    
    IEnumerator<INode> IEnumerable<INode>.GetEnumerator()
    {
      return alternatives.GetEnumerator();
    }
    
    IEnumerator IEnumerable.GetEnumerator()
    {
      return alternatives.GetEnumerator();
    }
  }
}