public void DeterministicParseEngineCanParseRegex()
{
var regexGrammar = new RegexGrammar();
var preComputedRegexGrammar = new PreComputedGrammar(regexGrammar);
var parseEngine = new DeterministicParseEngine(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, $"Error at position {i}");
}
Assert.IsTrue(parseEngine.IsAccepted(), "Parse was not accepted");
}
public void DeterministicParseEngineShouldParseRepeatingRightRecursiveRule()
{
var number = new NumberLexerRule();
var openBracket = new TerminalLexerRule('[');
var closeBracket = new TerminalLexerRule(']');
var comma = new TerminalLexerRule(',');
ProductionExpression
A = "A",
V = "V",
VR = "VR";
A.Rule = openBracket + VR + closeBracket;
VR.Rule = V
| V + comma + VR
| (Expr)null;
V.Rule = number;
var grammar = new GrammarExpression(
A, new[] { A, V, VR }).ToGrammar();
var determinisicParseEngine = new DeterministicParseEngine(grammar);
var tokens = new[]
{
new Token("[", 0, openBracket.TokenType),
new Token("1", 1, number.TokenType),
new Token(",", 2, comma.TokenType),
new Token("2", 3, number.TokenType),
new Token("]", 4, closeBracket.TokenType)
};
for (var i = 0; i < tokens.Length; i++)
{
var result = determinisicParseEngine.Pulse(tokens[i]);
if (!result)
{
Assert.Fail($"Failure parsing at position {determinisicParseEngine.Location}");
}
}
var accepted = determinisicParseEngine.IsAccepted();
if (!accepted)
{
Assert.Fail($"Input was not accepted.");
}
}
public void DeterministicParseEngineCanParseNullableGrammar()
{
var preComputedGrammar = new PreComputedGrammar(NullableGrammar);
var parseEngine = new DeterministicParseEngine(preComputedGrammar);
var input = "aaaa";
var tokenType = new TokenType("a");
for (int i = 0; i < input.Length; i++)
{
var result = parseEngine.Pulse(new Token("a", i, tokenType));
Assert.IsTrue(result, $"Error at position {i}");
}
Assert.IsTrue(parseEngine.IsAccepted(), "Parse was not accepted");
}