public void TestDotForDFA()
{
// Make sure it does not crash and does not return null.
var dfa = DFA.Create(NfaBuilder.Create(new ShuntingYard(new RegExLexer(new StringReader("(a|b)+bcd")))));
string dotString = dfa.AsDotNotation(null);
Assert.IsNotNull(dotString);
}
public void Should_be_able_to_mark_the_last_step_as_active_for_DFA()
{
// Make sure it does not crash and does not return null.
var dfa = DFA.Create(NfaBuilder.Create(new ShuntingYard(new RegExLexer(new StringReader("(a|b)+bcd")))));
string dotString = dfa.AsDotNotation("abc");
Assert.IsNotNull(dotString);
Assert.IsTrue(dotString.Contains("4 [ fillcolor=\"green\" style=\"filled\"]"));
}
/// <summary>
/// Get the DFA and NFA graphs for a given regular expression and highlight active
/// states for a given input string
/// </summary>
/// <param name="regex">Regular expression</param>
/// <param name="input">Input string</param>
/// <param name="minimize">Minimize the resulting DFA</param>
/// <param name="nfaString">Dot notation NFA graph</param>
/// <param name="dfaString">Dot notation DFA graph</param>
public static void GetDfaAndNfaGraphs(string regex, string input, bool minimize, out string nfaString, out string dfaString)
{
var nfa = NfaBuilder.Create(new ShuntingYard(new RegExLexer(new StringReader(regex))));
nfaString = nfa.AsDotNotation(input, "NFA");
var dfa = DFA.Create(nfa);
if (minimize)
{
dfa.Minimize();
}
dfaString = dfa.AsDotNotation(input, "DFA");
}
public ILexer <T> CreateLexer()
{
// For each token, create a NFA
IList <NFA> nfas = tokens.Select(token => NfaBuilder.Create(new ShuntingYard(new RegExLexer(new StringReader(token.Item1))))).ToList();
foreach (var ignoreExpr in ignore)
{
nfas.Add(NfaBuilder.Create(new ShuntingYard(new RegExLexer(new StringReader(ignoreExpr)))));
}
// Create a merged NFA
NFA mergedNfa = NFA.Merge(nfas);
// If we desire a NFA based lexer, stop now
if (Runtime == LexerRuntime.Nfa)
{
return(new NfaLexer <T>(mergedNfa, nfas, tokens, EndOfInputTokenNumber));
}
// Convert the NFA to a DFA
DFA dfa = DFA.Create(mergedNfa);
// Minimize the DFA if required
dfa.Minimize();
// If we desire a DFA based lexer, stop
if (Runtime == LexerRuntime.Dfa)
{
// TODO:
// The input ranges which will have been previously split into the smallest distinct
// units will need to be recombined in order for this to work as fast as possible.
//dfa.CombineInputRanges();
return(new DfaLexer <T>(dfa, nfas, tokens, EndOfInputTokenNumber));
}
// Convert the dfa to table form
var transitionTable = new TransitionTable <T>(dfa, nfas, tokens);
return(new TabularLexer <T>(transitionTable, EndOfInputTokenNumber));
}
private static DFA CreateDfa(string expression)
{
return(DFA.Create(NfaBuilder.Create(new ShuntingYard(new RegExLexer(new StringReader(expression))))));
}
public void TestOneOrMoreDFA()
{
NFA nfa = NfaBuilder.Create(new ShuntingYard(new RegExLexer(new StringReader("a+"))));
DFA dfa = DFA.Create(nfa);
}
public void TestCreateDFA2()
{
DFA dfa = DFA.Create(NfaBuilder.Create(new ShuntingYard(new RegExLexer(new StringReader("a|b|c")))));
}