Example #1
0
        public void MarpaParseEngineCanParseRegex()
        {
            var regexGrammar            = new RegexGrammar();
            var preComputedRegexGrammar = new PreComputedGrammar(regexGrammar);
            var parseEngine             = new MarpaParseEngine(preComputedRegexGrammar);

            var pattern = "[a-z][0-9]abc123";

            var openBracket     = new TokenType("[");
            var notMeta         = new TokenType("NotMeta");         // maybe make this token type a readonly property on the regex grammar?
            var notCloseBracket = new TokenType("NotCloseBracket"); // maybe make this token type a readonly property on the regex grammar?
            var closeBracket    = new TokenType("]");
            var dash            = new TokenType("-");

            for (int i = 0; i < pattern.Length; i++)
            {
                TokenType tokenType = (pattern[i]) switch
                {
                    '[' => openBracket,
                    ']' => closeBracket,
                    '-' => dash,
                    _ => i < 10
                          ? notCloseBracket
                          : notMeta,
                };
                var token  = new Token(pattern[i].ToString(), i, tokenType);
                var result = parseEngine.Pulse(token);
                Assert.IsTrue(result, $"Error at position {i}");
            }
            Assert.IsTrue(parseEngine.IsAccepted(), "Parse was not accepted");
        }
Example #2
0
        public void MarpaParseEngineShouldParseRightRecursiveGrammarInLinearTime()
        {
            var parseEngine = new MarpaParseEngine(new RightRecursionGrammar());
            var input       = "aaaaaaaaa";
            var tokens      = input.Select((a, i) =>
            {
                var value = a.ToString();
                return(new Token(value, i, new TokenType(value)));
            }).ToArray();

            for (var t = 0; t < tokens.Length; t++)
            {
                var token  = tokens[t];
                var result = parseEngine.Pulse(token);
                if (!result)
                {
                    Assert.Fail($"Error parsing at token position {t}");
                }
            }
            var accepted = parseEngine.IsAccepted();

            if (!accepted)
            {
                Assert.Fail($"Parse is not accepted. ");
            }

            var deterministicChart   = parseEngine.Chart;
            var lastDeterministicSet = deterministicChart.Sets[deterministicChart.Sets.Count - 1];

            Assert.AreEqual(4, lastDeterministicSet.States.Count);
        }
Example #3
0
        public void MarpaParseEngineShouldParseEncapsulatedRepeatingRightRecursiveRule()
        {
            var number       = new NumberLexerRule();
            var openBracket  = new TerminalLexerRule('[');
            var closeBracket = new TerminalLexerRule(']');
            var comma        = new TerminalLexerRule(',');

            ProductionExpression
                A  = "A",
                V  = "V",
                VR = "VR";

            A.Rule  = openBracket + VR + closeBracket;
            VR.Rule = V
                      | V + comma + VR
                      | (Expr)null;
            V.Rule = number;

            var grammar = new GrammarExpression(
                A, new [] { A, V, VR }).ToGrammar();

            var marpaParseEngine = new MarpaParseEngine(grammar);

            var tokens = new []
            {
                new Token("[", 0, openBracket.TokenType),
                new Token("1", 1, number.TokenType),
                new Token(",", 2, comma.TokenType),
                new Token("2", 3, number.TokenType),
                new Token("]", 4, closeBracket.TokenType)
            };

            for (var i = 0; i < tokens.Length; i++)
            {
                var result = marpaParseEngine.Pulse(tokens[i]);
                if (!result)
                {
                    Assert.Fail($"Failure parsing at position {marpaParseEngine.Location}");
                }
            }

            var accepted = marpaParseEngine.IsAccepted();

            if (!accepted)
            {
                Assert.Fail($"Input was not accepted.");
            }
        }
        public void MarpaParseEngineCanParseRegex()
        {
            var regexGrammar            = new RegexGrammar();
            var preComputedRegexGrammar = new PreComputedGrammar(regexGrammar);
            var parseEngine             = new MarpaParseEngine(preComputedRegexGrammar);

            var pattern = "[a-z][0-9]abc123";

            var openBracket     = new TokenType("[");
            var notMeta         = new TokenType("NotMeta");         // maybe make this token type a readonly property on the regex grammar?
            var notCloseBracket = new TokenType("NotCloseBracket"); // maybe make this token type a readonly property on the regex grammar?
            var closeBracket    = new TokenType("]");
            var dash            = new TokenType("-");

            for (int i = 0; i < pattern.Length; i++)
            {
                TokenType tokenType = null;
                switch (pattern[i])
                {
                case '[':
                    tokenType = openBracket;
                    break;

                case ']':
                    tokenType = closeBracket;
                    break;

                case '-':
                    tokenType = dash;
                    break;

                default:
                    if (i < 10)
                    {
                        tokenType = notCloseBracket;
                    }
                    else
                    {
                        tokenType = notMeta;
                    }
                    break;
                }
                var token  = new Token(pattern[i].ToString(), i, tokenType);
                var result = parseEngine.Pulse(token);
                Assert.IsTrue(result, $"Error at position {i}");
            }
            Assert.IsTrue(parseEngine.IsAccepted(), "Parse was not accepted");
        }
Example #5
0
        public void MarpaParseEngineShouldNotMemoizeRuleWhenSiblingIsRightRecursiveAndCurrentRuleIsNot()
        {
            ProductionExpression
                S = "S",
                A = "A";

            S.Rule = A;
            A.Rule = (Expr)'a' + 'a' + A
                     | (Expr)'b' + 'b';

            var grammar          = new GrammarExpression(S, new[] { S, A }).ToGrammar();
            var marpaParseEngine = new MarpaParseEngine(grammar);

            var bTokenType = new TokenType("b");
            var tokens     = new[]
            {
                new Token("b", 0, bTokenType),
                new Token("b", 1, bTokenType)
            };

            for (var i = 0; i < tokens.Length; i++)
            {
                var result = marpaParseEngine.Pulse(tokens[i]);
                if (!result)
                {
                    Assert.Fail($"Failure parsing at position {marpaParseEngine.Location}");
                }
            }

            var accepted = marpaParseEngine.IsAccepted();

            if (!accepted)
            {
                Assert.Fail($"Input was not accepted.");
            }
        }