CFGLib.CFGtoCNF.Convert C# (CSharp) Method

		internal CNFGrammar Convert() {
			if (_used) {
				throw new Exception("You can only use this object once");
			}
			_used = true;

			var productions = GrammarHelpers.CloneGrammar(_grammar);
			StepStart(productions);
			StepTerm(productions);
			StepBin(productions);
			StepDel(productions);
			StepUnit(productions);

			var resultProductions = new List<Production>();
			//var nonterminalProductions = new List<Production>();
			//var terminalProductions = new List<Production>();
			var producesEmptyWeight = 0.0;
			
			foreach (var production in productions) {
				if (production.Rhs.Count > 2) {
					throw new Exception("Didn't expect more than 2");
				} else if (production.Rhs.Count == 2) {
					resultProductions.Add(production);
				} else if (production.Rhs.Count == 1) {
					var rhs = production.Rhs[0];
					if (rhs.IsNonterminal) {
						throw new Exception("Didn't expect unit production");
					}
					resultProductions.Add(production);
				} else if (production.Rhs.Count == 0) {
					producesEmptyWeight += production.Weight;
						// GetGrammarFromProductionList(production, productions);
				}
			}

			resultProductions.Add(new Production(_startSymbol, new Sentence(), producesEmptyWeight));

			return new CNFGrammar(resultProductions, _startSymbol);
		}

        /// <summary>
        /// Returns a new grammar that is the CNF equivalent of this grammar.
        /// WARNING: currently this does not always preserve probabilities!
        /// </summary>
        public CNFGrammar ToCNF()
        {
            var conv = new CFGtoCNF(this);

            return(conv.Convert());
        }