source: branches/HeuristicLab.Problems.GPDL/HeuristicLab.Grammars/3.3/AttributedGrammar.cs @ 10067

#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab 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 HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;

namespace HeuristicLab.Grammars {
  public class AttributedGrammar : Grammar {
    private Dictionary<ISymbol, string> localDefinitions = new Dictionary<ISymbol, string>();
    private Dictionary<ISymbol, IList<Sequence>> alternatives = new Dictionary<ISymbol, IList<Sequence>>();

    public AttributedGrammar(ISymbol startSymbol)
      : base(startSymbol) {
      Debug.Assert(!startSymbol.Equals(EmptySymbol));
      this.StartSymbol = startSymbol;
    }

    public IEnumerable<Sequence> GetAlternativesWithSemanticActions(ISymbol ntSymbol) {
      Debug.Assert(!ntSymbol.Equals(EmptySymbol));
      return alternatives[ntSymbol];
    }
    public Sequence GetAlternativeWithSemanticActions(ISymbol ntSymbol, int index) {
      Debug.Assert(!ntSymbol.Equals(EmptySymbol));
      return alternatives[ntSymbol][index];
    }

    public override void AddProductionRule(ISymbol ntSymbol, Sequence production) {
      base.AddProductionRule(ntSymbol, new Sequence(production.Where(symb => !(symb is SemanticSymbol)).ToList()));

      IList<Sequence> list;
      if (!alternatives.TryGetValue(ntSymbol, out list)) {
        list = new List<Sequence>();
        alternatives.Add(ntSymbol, list);
      }
      // make sure that there is not equivalent production registered already
      Debug.Assert(!list.Any(s => s.SequenceEqual(production)));

      list.Add(production);
    }

    public void AddLocalDefinitions(ISymbol ntSymbol, string localDefCode) {
      Debug.Assert(!ntSymbol.Equals(EmptySymbol));
      Debug.Assert(!localDefinitions.ContainsKey(ntSymbol));

      localDefinitions.Add(ntSymbol, localDefCode);
    }
    public string GetLocalDefinitions(ISymbol ntSymbol) {
      string code;
      if (localDefinitions.TryGetValue(ntSymbol, out code)) return code;
      else return string.Empty;
    }



    //private static Regex ruleExpr = new Regex(@"\s*(?<ntSymbol>\w+)\s*(?<formPar>\<\w+\>)+\s*->\s*(?<alternative>\w+\s*(?<actPar>\<\w+\>)+(?:\s+\w+\s*(?<actPar>\<\w+\>)+)*)(?:\s*\|\s*(?<alternative>\w+\s*(?<formPar>\<\w+\>)+(?:\s+\w+\s*(?<formPar>\<\w+\>)+)*))*");
    //private static Regex empty = new Regex(@"^\s*$");
    //public static Grammar FromString(string gStr) {
    //  var lines = gStr.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
    //  lines = lines.Where(l => !empty.IsMatch(l)).ToArray(); // remove empty lines

    //  // first line is the rule for the start-symbol
    //  var m = ruleExpr.Match(lines.First());
    //  var startSymbol = new Symbol(m.Groups["ntSymbol"].Value);

    //  var g = new Grammar(startSymbol);
    //  foreach (var alt in m.Groups["alternative"].Captures) {
    //    g.AddProductionRule(startSymbol, new Sequence(alt.ToString().Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries).Select(n => new Symbol(n))));
    //  }
    //  foreach (var line in lines.Skip(1)) {
    //    m = ruleExpr.Match(line);
    //    var ntSymbol = new Symbol(m.Groups["ntSymbol"].Value);
    //    foreach (var alt in m.Groups["alternative"].Captures) {
    //      g.AddProductionRule(ntSymbol, new Sequence(alt.ToString().Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries).Select(n => new Symbol(n))));
    //    }
    //  }

    //  return g;
    //}
  }
}