Beispiel #1
0
		public static void Do() {
			// S -> aSa | bSb | ε
			var productions = new List<Production> {
				// construct productions by passing arguments...
				new Production(
					lhs: Nonterminal.Of("S"),
					rhs: new Sentence { Terminal.Of("a"), Nonterminal.Of("S"), Terminal.Of("a") },
					weight: 20
				),
				// or from a string...
				CFGParser.Production(@"<S> -> 'b' <S> 'b' [10]"),
				CFGParser.Production(@"<S> -> ε [5]"),
			};
			var cfg = new Grammar(productions, Nonterminal.Of("S"));
			// var cnf = cfg.ToCNF();

			//var probs = cfg.EstimateProbabilities(1000000);
			//foreach (var entry in probs) {
			//	var key = entry.Key;
			//	var value = entry.Value;
			//	if (key.Length <= 4) {
			//	Console.WriteLine("{0}: {1}", key, value);
			//	}
			//}

			// Print out the new CNF grammar
			// Console.WriteLine(cnf);

			var ep = new EarleyParser(cfg);
			// var cp = new CykParser(cnf);

			// Does this grammar accept the string "aabb"?
			Console.WriteLine("aabb: {0}", ep.ParseGetProbability(Sentence.FromLetters("aabb")));
			// How about "abba"?
			Console.WriteLine("abba: {0}", ep.ParseGetProbability(Sentence.FromLetters("abba")));

			Console.WriteLine(ep.ParseGetForest(Sentence.FromLetters("abba")));

			for (int i = 0; i < 5; i++) {
				Console.WriteLine(cfg.ProduceRandom().AsTerminals());
			}

			var sentences = cfg.ProduceToDepth(3);
			foreach (var sentence in sentences) {
				Console.WriteLine(sentence.Value.AsTerminals());
			}

			var gg = new GrammarGenerator(1);
			var terminals = new List<Terminal> { Terminal.Of("a"), Terminal.Of("b") };
			var randGram = gg.NextCFG(
				numNonterminals: 4,
				numProductions: 10,
				maxProductionLength: 4,
				terminals: terminals
			);
			Console.WriteLine(randGram);
		}
Beispiel #2
0
		private static void ExecuteTest(Grammar g, List<Sentence> sentences) {
			CNFGrammar h = g.ToCNF();
			var earley = new EarleyParser(g);
			var cyk = new CykParser(h);

			foreach (var sentence in sentences) {
				var p1 = cyk.ParseGetProbability(sentence);
				var p2 = earley.ParseGetProbability(sentence);
				Helpers.AssertNear(p1, p2);
			}
		}
Beispiel #3
0
        private static void ExecuteTest(Grammar g, string input)
        {
            var earley1  = new EarleyParser(g);
            var earley2  = new EarleyParser2(g);
            var sentence = Sentence.FromWords(input);

            var p1 = earley1.ParseGetProbability(sentence);
            var p2 = earley2.ParseGetProbability(sentence);

            Helpers.AssertNear(p1, p2);
        }
Beispiel #4
0
        private static void ExecuteTest(Grammar g, List <Sentence> sentences)
        {
            CNFGrammar h      = g.ToCNF();
            var        earley = new EarleyParser(g);
            var        cyk    = new CykParser(h);

            foreach (var sentence in sentences)
            {
                var p1 = cyk.ParseGetProbability(sentence);
                var p2 = earley.ParseGetProbability(sentence);
                Helpers.AssertNear(p1, p2);
            }
        }
Beispiel #5
0
        private static void BnfParse(Sentence sentence)
        {
            var g = Bnf.Grammar();
            //var h = g.ToCNF(); // too much memory
            var earley = new EarleyParser(g);
            // var cyk = new CykParser(h);
            var earley2 = new EarleyParser2(g);

            // var p1 = cyk.ParseGetProbability(sentence);
            var p2 = earley.ParseGetProbability(sentence);
            var p3 = earley2.ParseGetProbability(sentence);

            // Helpers.AssertNear(p1, p2);
            Helpers.AssertNear(p2, p3);
            Assert.IsTrue(p2 > 0.0);
        }
Beispiel #6
0
        public static void Do()
        {
            // S -> aSa | bSb | ε
            var productions = new List <Production> {
                // construct productions by passing arguments...
                new Production(
                    lhs: Nonterminal.Of("S"),
                    rhs: new Sentence {
                    Terminal.Of("a"), Nonterminal.Of("S"), Terminal.Of("a")
                },
                    weight: 20
                    ),
                // or from a string...
                CFGParser.Production(@"<S> -> 'b' <S> 'b' [10]"),
                CFGParser.Production(@"<S> -> ε [5]"),
            };
            var cfg = new Grammar(productions, Nonterminal.Of("S"));
            // var cnf = cfg.ToCNF();

            //var probs = cfg.EstimateProbabilities(1000000);
            //foreach (var entry in probs) {
            //	var key = entry.Key;
            //	var value = entry.Value;
            //	if (key.Length <= 4) {
            //	Console.WriteLine("{0}: {1}", key, value);
            //	}
            //}

            // Print out the new CNF grammar
            // Console.WriteLine(cnf);

            var ep = new EarleyParser(cfg);

            // var cp = new CykParser(cnf);

            // Does this grammar accept the string "aabb"?
            Console.WriteLine("aabb: {0}", ep.ParseGetProbability(Sentence.FromLetters("aabb")));
            // How about "abba"?
            Console.WriteLine("abba: {0}", ep.ParseGetProbability(Sentence.FromLetters("abba")));

            Console.WriteLine(ep.ParseGetForest(Sentence.FromLetters("abba")));

            for (int i = 0; i < 5; i++)
            {
                Console.WriteLine(cfg.ProduceRandom().AsTerminals());
            }

            var sentences = cfg.ProduceToDepth(3);

            foreach (var sentence in sentences)
            {
                Console.WriteLine(sentence.Value.AsTerminals());
            }

            var gg        = new GrammarGenerator(1);
            var terminals = new List <Terminal> {
                Terminal.Of("a"), Terminal.Of("b")
            };
            var randGram = gg.NextCFG(
                numNonterminals: 4,
                numProductions: 10,
                maxProductionLength: 4,
                terminals: terminals
                );

            Console.WriteLine(randGram);
        }
Beispiel #7
0
		public void RandomParsingTest(
			int _numGrammars = 10000,
			int _numNonterminals = 10,
			int _numTerminals = 5,
			int _numProductions = 30,
			int _maxProductionLength = 8,
			int _maxInputLength = 6,
			int seed = 0
		) {
			var printStatus = true;

			var range = Enumerable.Range(0, _numTerminals);
			var terminals = new List<Terminal>(range.Select((x) => Terminal.Of("x" + x)));
			Console.WriteLine("Preparing sentences");
			var preparedSentences = new List<Sentence>();
			for (int length = 0; length <= _maxInputLength; length++) {
				var combinations = CFGLibTest.Helpers.CombinationsWithRepetition(terminals, length);
				foreach (var target in combinations) {
					var sentence = new Sentence(target);
					preparedSentences.Add(sentence);
				}
			}

			var randg = new GrammarGenerator(seed);
			var preparedGrammars = new List<Grammar>(_numGrammars);
			var preparedGrammarsCNF = new List<CNFGrammar>(_numGrammars);
			Console.WriteLine("Preparing grammars");
			for (int i = 0; i < _numGrammars; i++) {
				Grammar g = null;
				while (g == null) {
					// g = randg.NextCNF(_numNonterminals, _numProductions, terminals);
					g = randg.NextCFG(_numNonterminals, _numProductions, _maxProductionLength, terminals, true);
					if (g.Productions.Count() == 0) {
						g = null;
					}
				}
				// Console.WriteLine("---------------{0}/{1}---------------", i.ToString("D5"), _numGrammars.ToString("D5"));
				// Console.WriteLine(g.ToCodeString());
				var h = g.ToCNF();
				//return;
				// Console.WriteLine(g);
				// g.PrintProbabilities(2, 3);
				preparedGrammars.Add(g);
				preparedGrammarsCNF.Add(h);
			}
			Console.WriteLine("starting");
			var sw = Stopwatch.StartNew();
			int count = 0;
			for (int grammarIndex = 0; grammarIndex < _numGrammars; grammarIndex++) {
				if (printStatus) {
					Console.WriteLine("---------------{0}/{1}---------------", grammarIndex.ToString("D5"), _numGrammars.ToString("D5"));
				}

				var g = preparedGrammars[grammarIndex];
				var h = preparedGrammarsCNF[grammarIndex];

				var earley = new EarleyParser(g);
				var cyk = new CykParser(h);

				// Console.WriteLine(g.ToCodeString());
				// Console.Write("{0}, ", count);
				count++;
				var accepts = 0;
				foreach (var sentence in preparedSentences) {
					try {
						var p1 = earley.ParseGetProbability(sentence);
						var p2 = cyk.ParseGetProbability(sentence);
						if (!Helpers.IsNear(p2, p1)) {
							throw new Exception();
						}
						var accepts1 = p1 > 0;
						var accepts2 = p2 > 0;

						if (accepts2) {
							accepts++;
						}
					} catch (Exception) {
						Report(g, sentence);
						throw;
					}
				}
				if (printStatus) {
					Console.WriteLine("Accepted {0} / {1}", accepts, preparedSentences.Count);
				}
			}
			sw.Stop();
			Console.WriteLine();
			Console.WriteLine("inner Elapsed: {0}s", sw.Elapsed.TotalMilliseconds / 1000.0);
			// Console.WriteLine("Per CYK: {0}ms", sw.Elapsed.TotalMilliseconds / (_numGrammars * preparedSentences.Count));
		}
Beispiel #8
0
        public void RandomParsingTest(
            int _numGrammars         = 10000,
            int _numNonterminals     = 10,
            int _numTerminals        = 5,
            int _numProductions      = 30,
            int _maxProductionLength = 8,
            int _maxInputLength      = 6,
            int seed = 0
            )
        {
            var printStatus = true;

            var range     = Enumerable.Range(0, _numTerminals);
            var terminals = new List <Terminal>(range.Select((x) => Terminal.Of("x" + x)));

            Console.WriteLine("Preparing sentences");
            var preparedSentences = new List <Sentence>();

            for (int length = 0; length <= _maxInputLength; length++)
            {
                var combinations = CFGLibTest.Helpers.CombinationsWithRepetition(terminals, length);
                foreach (var target in combinations)
                {
                    var sentence = new Sentence(target);
                    preparedSentences.Add(sentence);
                }
            }

            var randg               = new GrammarGenerator(seed);
            var preparedGrammars    = new List <Grammar>(_numGrammars);
            var preparedGrammarsCNF = new List <CNFGrammar>(_numGrammars);

            Console.WriteLine("Preparing grammars");
            for (int i = 0; i < _numGrammars; i++)
            {
                Grammar g = null;
                while (g == null)
                {
                    // g = randg.NextCNF(_numNonterminals, _numProductions, terminals);
                    g = randg.NextCFG(_numNonterminals, _numProductions, _maxProductionLength, terminals, true);
                    if (g.Productions.Count() == 0)
                    {
                        g = null;
                    }
                }
                // Console.WriteLine("---------------{0}/{1}---------------", i.ToString("D5"), _numGrammars.ToString("D5"));
                // Console.WriteLine(g.ToCodeString());
                var h = g.ToCNF();
                //return;
                // Console.WriteLine(g);
                // g.PrintProbabilities(2, 3);
                preparedGrammars.Add(g);
                preparedGrammarsCNF.Add(h);
            }
            Console.WriteLine("starting");
            var sw    = Stopwatch.StartNew();
            int count = 0;

            for (int grammarIndex = 0; grammarIndex < _numGrammars; grammarIndex++)
            {
                if (printStatus)
                {
                    Console.WriteLine("---------------{0}/{1}---------------", grammarIndex.ToString("D5"), _numGrammars.ToString("D5"));
                }

                var g = preparedGrammars[grammarIndex];
                var h = preparedGrammarsCNF[grammarIndex];

                var earley = new EarleyParser(g);
                var cyk    = new CykParser(h);

                // Console.WriteLine(g.ToCodeString());
                // Console.Write("{0}, ", count);
                count++;
                var accepts = 0;
                foreach (var sentence in preparedSentences)
                {
                    try {
                        var p1 = earley.ParseGetProbability(sentence);
                        var p2 = cyk.ParseGetProbability(sentence);
                        if (!Helpers.IsNear(p2, p1))
                        {
                            throw new Exception();
                        }
                        var accepts1 = p1 > 0;
                        var accepts2 = p2 > 0;

                        if (accepts2)
                        {
                            accepts++;
                        }
                    } catch (Exception) {
                        Report(g, sentence);
                        throw;
                    }
                }
                if (printStatus)
                {
                    Console.WriteLine("Accepted {0} / {1}", accepts, preparedSentences.Count);
                }
            }
            sw.Stop();
            Console.WriteLine();
            Console.WriteLine("inner Elapsed: {0}s", sw.Elapsed.TotalMilliseconds / 1000.0);
            // Console.WriteLine("Per CYK: {0}ms", sw.Elapsed.TotalMilliseconds / (_numGrammars * preparedSentences.Count));
        }