public static XElement getTwoWordsInstructorFeedback(XElement regex, XElement xAlphabet, XElement first, XElement second)
{
string firstString = (XElement.Parse(DFAUtilities.RemoveAllNamespaces(first.ToString()))).Value.Trim();
string secondString = (XElement.Parse(DFAUtilities.RemoveAllNamespaces(second.ToString()))).Value.Trim();
HashSet <char> alphabet = parseAlphabet(xAlphabet);
CharSetSolver solver = new CharSetSolver(BitWidth.BV64);
var dfaPair = DFAUtilities.parseRegexFromXML(regex, xAlphabet, solver);
var dfa = dfaPair.Second.Determinize(solver).Minimize(solver);
firstString = firstString.decodeEpsilon();
secondString = secondString.decodeEpsilon();
int firstState = DFAUtilities.GetStateAfterString(dfa.InitialState, firstString, dfa, solver);
int secondState = DFAUtilities.GetStateAfterString(dfa.InitialState, secondString, dfa, solver);
bool areEquivalent = (firstState == secondState);
if (areEquivalent)
{
var suffixDfa = Automaton <BDD> .Create(firstState, dfa.GetFinalStates(), dfa.GetMoves());
var suffixRegex = solver.ConvertToRegex(suffixDfa);
suffixRegex = regexToTraditional(suffixRegex);
return(XElement.Parse(String.Format("<div><feedback> The words '{0}' and '{1}' are equivalent. The language of suffixes is '{2}'</feedback></div>", firstString, secondString, suffixRegex)));
}
else
{
var shortestDiff = DFAUtilities.GetDifferentiatingWord(firstState, secondState, dfa, alphabet, solver).Second;
return(XElement.Parse(String.Format("<div><feedback> The words '{0}' and '{1}' are NOT equivalent. The shortest differentiating word is '{2}'</feedback></div>", firstString, secondString, shortestDiff)));
}
}
public static XElement getSameFeedback(XElement regex, XElement xAlphabet, XElement first, XElement second, XElement notEquivalent, XElement reason, XElement maxGrade)
{
string firstString = (XElement.Parse(DFAUtilities.RemoveAllNamespaces(first.ToString()))).Value.Trim().decodeEpsilon();
string secondString = (XElement.Parse(DFAUtilities.RemoveAllNamespaces(second.ToString()))).Value.Trim().decodeEpsilon();
string reasonString = (XElement.Parse(DFAUtilities.RemoveAllNamespaces(reason.ToString()))).Value.Trim();
bool areEquivalentAttempt = int.Parse(notEquivalent.Value) == 1 ? false : true;
int maxG = int.Parse(maxGrade.Value);
HashSet <char> alphabet = parseAlphabet(xAlphabet);
CharSetSolver solver = new CharSetSolver(BitWidth.BV64);
var dfaPair = DFAUtilities.parseRegexFromXML(regex, xAlphabet, solver);
var dfa = dfaPair.Second.Minimize(solver);
int firstState = DFAUtilities.GetStateAfterString(dfa.InitialState, firstString, dfa, solver);
int secondState = DFAUtilities.GetStateAfterString(dfa.InitialState, secondString, dfa, solver);
bool areEquivalent = (firstState == secondState);
if (areEquivalent != areEquivalentAttempt)
{
return(XElement.Parse(string.Format("<div><grade>0</grade><feedback>Wrong equivalency assesment!</feedback></div>")));
}
else if (areEquivalent)
{
try
{
var suffixDfa = Automaton <BDD> .Create(firstState, dfa.GetFinalStates(), dfa.GetMoves());
var reasonDfaPair = DFAUtilities.parseRegexFromXML(reason, xAlphabet, solver);
var dfaGradingFeedback = DFAGrading.GetGrade(suffixDfa, reasonDfaPair.Second, alphabet, solver, 1500, maxG, FeedbackLevel.Minimal, false, false, true);
var feedString = "<div>";
foreach (var feed in dfaGradingFeedback.Second)
{
feedString += string.Format("{0}<br />", feed);
}
feedString += "</div>";
if (maxG == dfaGradingFeedback.First)
{
return(XElement.Parse(string.Format("<div><grade>{0}</grade><feedback>Correct!</feedback></div>", maxG)));
}
else
{
return(XElement.Parse(string.Format("<div><grade>{0}</grade><feedback>{1}</feedback></div>", Math.Max((int)(maxG / 3), dfaGradingFeedback.First), feedString)));
}
}
catch (PDLException pdlex)
{
return(XElement.Parse(string.Format("<div><grade>{0}</grade><feedback>Parsing Error: {1}</feedback></div>", (int)(maxG / 3), pdlex.Message)));
}
}
else
{
// Finding a shortest differentiating word
var shortestDiff = DFAUtilities.GetDifferentiatingWord(firstState, secondState, dfa, alphabet, solver).Second;
reasonString = reasonString.decodeEpsilon();
int endFirst = DFAUtilities.GetStateAfterString(firstState, reasonString, dfa, solver);
int endSecond = DFAUtilities.GetStateAfterString(secondState, reasonString, dfa, solver);
bool c1 = dfa.GetFinalStates().Contains(endFirst);
bool c2 = dfa.GetFinalStates().Contains(endSecond);
if (c1 ^ c2)
{
return(XElement.Parse(string.Format("<div><grade>{0}</grade><feedback>Correct!</feedback></div>", maxG)));
}
else
{
string feedString = string.Format("The words '{0}' and '{2}' are both {1} by the language", (firstString + reasonString).emptyToEpsilon(), c1 ? "accepted" : "not accepted", (secondString + reasonString).emptyToEpsilon());
return(XElement.Parse(string.Format("<div><grade>{0}</grade><feedback>{1}</feedback></div>", (int)(maxG / 3), feedString)));
}
}
}