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 DfaLexemeResetShouldResetLexemeValues()
{
var numberLexerRule = new NumberLexerRule();
var lexeme = numberLexerRule.CreateLexeme(0);
const string numberInput = "0123456";
foreach (var character in numberInput)
{
var result = lexeme.Scan(character);
if (!result)
{
Assert.Fail($"Did not recognize number {character}");
}
}
}
public void DfaLexemeResetShouldResetLexemeValues()
{
var numberLexerRule = new NumberLexerRule();
var whitespaceLexerRule = new WhitespaceLexerRule();
var lexeme = new DfaLexeme(numberLexerRule, 0);
const string numberInput = "0123456";
for (var i = 0; i < numberInput.Length; i++)
{
var result = lexeme.Scan(numberInput[i]);
if (!result)
{
Assert.Fail($"Did not recognize number {numberInput[i]}");
}
}
lexeme.Reset(whitespaceLexerRule, 50);
Assert.AreEqual(string.Empty, lexeme.Value);
Assert.AreEqual(50, lexeme.Position);
Assert.AreEqual(whitespaceLexerRule.LexerRuleType, lexeme.LexerRule.LexerRuleType);
Assert.AreEqual(whitespaceLexerRule.TokenType, lexeme.TokenType);
}
static ExpressionGrammar()
{
var number = new NumberLexerRule();
ProductionExpression
S = nameof(S),
E = nameof(E),
T = nameof(T),
F = nameof(F);
S.Rule = E;
E.Rule = E + '+' + T
| E + '-' + T
| T;
T.Rule = T + '*' + F
| T + '/' + F
| F;
F.Rule = '+' + F
| '-' + F
| number
| '(' + E + ')';
_grammar = new GrammarExpression(S).ToGrammar();
}
