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 bool compareNfaToRegex(XElement regex, XElement alphabet, XElement attemptNfa)
{
CharSetSolver solver = new CharSetSolver(BitWidth.BV64);
var dfaCorrectPair = DFAUtilities.parseRegexFromXML(regex, alphabet, solver);
var attempt = DFAUtilities.parseBlockFromXML(attemptNfa, alphabet, solver);
var same = dfaCorrectPair.Second.IsEquivalentWith(attempt.Second, solver);
return(same);
}
public static XElement getShortestFeedback(XElement regex, XElement xAlphabet, XElement representative, XElement attemptShortest, XElement maxGrade)
{
int maxG = int.Parse(maxGrade.Value);
CharSetSolver solver = new CharSetSolver(BitWidth.BV64);
var dfaPair = DFAUtilities.parseRegexFromXML(regex, xAlphabet, solver);
var dfa = dfaPair.Second.Minimize(solver);
string representativeString = (XElement.Parse(DFAUtilities.RemoveAllNamespaces(representative.ToString()))).Value.Trim();
representativeString = representativeString.decodeEpsilon();
string attemptShortestString = (XElement.Parse(DFAUtilities.RemoveAllNamespaces(attemptShortest.ToString()))).Value.Trim();
attemptShortestString = attemptShortestString.decodeEpsilon();
int representativeState = DFAUtilities.GetStateAfterString(dfa.InitialState, representativeString, dfa, solver);
int attemptShortestState = DFAUtilities.GetStateAfterString(dfa.InitialState, attemptShortestString, dfa, solver);
xAlphabet = XElement.Parse(DFAUtilities.RemoveAllNamespaces(xAlphabet.ToString()));
HashSet <char> alphabet = parseAlphabet(xAlphabet);
string correctShortest = DFAUtilities.GetRepresentative(representativeState, dfa, alphabet, solver);
if (correctShortest.Equals(attemptShortestString))
{
return(XElement.Parse(string.Format("<div><grade>{0}</grade><feedback>Correct!</feedback></div>", maxG)));
}
else if (attemptShortestState == representativeState)
{
if (representativeString.Equals(attemptShortestString))
{
return(XElement.Parse(string.Format("<div><grade>{0}</grade><feedback>Please provide a different word than the given one</feedback></div>", 0)));
}
else if (attemptShortestString.Length > correctShortest.Length)
{
return(XElement.Parse(string.Format("<div><grade>{0}</grade><feedback>The word '{1}' is in the same equivalence class as '{2}' but there exists a shorter one</feedback></div>", (int)(maxG * 2 / 3), attemptShortestString.emptyToEpsilon(), representativeString.emptyToEpsilon())));
}
else
{
return(XElement.Parse(string.Format("<div><grade>{0}</grade><feedback>The word '{1}' is in the same equivalence class as '{2}' but there exists a <strong>lexicographically smaller</strong> one</feedback></div>", (int)(maxG * 4 / 5), attemptShortestString.emptyToEpsilon(), representativeString.emptyToEpsilon())));
}
}
else
{
string feedString = "Incorrect!";//"The Correct Answer is '" + correctShortest + "'";
return(XElement.Parse(string.Format("<div><grade>{0}</grade><feedback>{1}</feedback></div>", 0, feedString)));
}
}
public static XElement getWordsFeedback(XElement regex, XElement xAlphabet, XElement representative, XElement wordsIn, XElement maxGrade)
{
//read inputs
int maxG = int.Parse(maxGrade.Value);
List <string> wordsInList = new List <String>();
HashSet <string> usedWords = new HashSet <string>();
foreach (var wordElement in wordsIn.Elements())
{
string w = wordElement.Value;
if (w.Length > 75)
{
w = w.Substring(0, 75); //limit word length
}
w = w.decodeEpsilon();
wordsInList.Add(w);
}
HashSet <char> alphabet = parseAlphabet(xAlphabet);
string alphabetString = alphabetToString(alphabet);
CharSetSolver solver = new CharSetSolver(BitWidth.BV64);
var dfaPair = DFAUtilities.parseRegexFromXML(regex, xAlphabet, solver);
var dfa = dfaPair.Second.Minimize(solver);
string representativeString = (XElement.Parse(DFAUtilities.RemoveAllNamespaces(representative.ToString()))).Value.Trim();
representativeString = representativeString.decodeEpsilon();
int representativeState = DFAUtilities.GetStateAfterString(dfa.InitialState, representativeString, dfa, solver);
string feedString = "<ul>";
int correct = 0;
int total = wordsInList.Count;
usedWords.Add(representativeString);
foreach (string s in wordsInList)
{
//TODO: Check string only contains valid characters
if (usedWords.Contains(s))
{
if (s.Equals(representativeString))
{
feedString += String.Format("<li> The word '{0}' was provided by the instructor </li>", s.emptyToEpsilon());
}
else
{
feedString += String.Format("<li> The word '{0}' was already used </li>", s.emptyToEpsilon());
}
continue;
}
bool overValidAlphabet = true;
foreach (char c in s)
{
if (!alphabet.Contains(c))
{
overValidAlphabet = false;
}
}
if (!overValidAlphabet)
{
feedString += String.Format("<li> The word '{0}' is not over the alphabet {1} </li>", s.emptyToEpsilon(), alphabetString);
continue;
}
usedWords.Add(s);
int wordState = DFAUtilities.GetStateAfterString(dfa.InitialState, s, dfa, solver);
if (wordState == representativeState)
{
correct++;
}
else
{
feedString += String.Format("<li> The word '{0}' is not in the same equivalence class as '{1}' </li>", s.emptyToEpsilon(), representativeString.emptyToEpsilon());
}
}
feedString += "</ul>";
var grade = 1.0 * int.Parse(maxGrade.Value) * correct / total;
if (grade == maxG)
{
feedString = "Correct!";
}
return(XElement.Parse(string.Format("<div><grade>{0}</grade><feedback>{1}</feedback></div>", (int)(Math.Ceiling(grade)), feedString)));
}
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)));
}
}
}