private static void AssertLexerRuleMatches(DfaLexerRule lexerRule, string input)
{
var lexeme = lexerRule.CreateLexeme(0);
for (var i = 0; i < input.Length; i++)
{
Assert.IsTrue(lexeme.Scan(input[i]), $"character '{input[i]}' not recognized at position {i}.");
}
Assert.IsTrue(lexeme.IsAccepted(), $"input {input} not accepted.");
}
public void RegexToDfaShouldConvertCharacterRegexToDfa()
{
var pattern = "a";
var dfa = CreateDfaFromRegexPattern(pattern);
Assert.IsNotNull(dfa);
var lexerRule = new DfaLexerRule(dfa, "a");
var lexeme = lexerRule.CreateLexeme(0);
Assert.IsTrue(lexeme.Scan('a'));
}
public void DfaLexemeGivenCharacerLexemeNumberShouldFail()
{
var numberInput = "0";
var dfa = DfaState.Inner();
var final = DfaState.Final();
dfa.AddTransition(new RangeTerminal('a', 'z'), final);
final.AddTransition(new RangeTerminal('a', 'z'), final);
var dfaLexerRule = new DfaLexerRule(dfa, new TokenName("lowerCase"));
var letterLexeme = dfaLexerRule.CreateLexeme(0);
Assert.IsFalse(letterLexeme.Scan(numberInput[0]));
Assert.AreEqual(string.Empty, letterLexeme.Value);
}
public void DfaLexemeShouldMatchOneOrMoreRandomWhitespaceCharacters()
{
var randomWhitespace = "\t\f\v \r\n";
var dfa = DfaState.Inner();
var final = DfaState.Final();
dfa.AddTransition(WhitespaceTerminal.Instance, final);
final.AddTransition(WhitespaceTerminal.Instance, final);
var dfaLexerRule = new DfaLexerRule(dfa, new TokenName("whitespace"));
var whitespaceLexeme = dfaLexerRule.CreateLexeme(0);
foreach (var character in randomWhitespace)
{
Assert.IsTrue(whitespaceLexeme.Scan(character));
}
}
public void DfaLexemeShouldMatchMixedCaseWord()
{
var wordInput = "t90vAriabl3";
var dfa = DfaState.Inner();
var final = DfaState.Final();
dfa.AddTransition(new RangeTerminal('a', 'z'), final);
dfa.AddTransition(new RangeTerminal('A', 'Z'), final);
final.AddTransition(new RangeTerminal('a', 'z'), final);
final.AddTransition(new RangeTerminal('A', 'Z'), final);
final.AddTransition(DigitTerminal.Instance, final);
var dfaLexerRule = new DfaLexerRule(dfa, new TokenName("Identifier"));
var indentifierLexeme = dfaLexerRule.CreateLexeme(0);
foreach (var character in wordInput)
{
Assert.IsTrue(indentifierLexeme.Scan(character));
}
}