/// <summary>
/// Translation from concatenation (dot) (rule 3)
/// </summary>
/// <param name="reg">the regular expression created with the RegExp class</param>
/// <param name="automaton">the NDFA</param>
/// <param name="stateCounter">keeps track of the next state to add</param>
/// <param name="leftState">From state</param>
/// <param name="rightState">To state</param>
public static void Regel3(RegExp reg, List <Node> automaton, int stateCounter, int leftState, int rightState)
{
var newState = stateCounter + 1;
stateCounter = newState;
//node c, a dot means that there is atleast 1 new node
automaton.Add(new Node(new List <Connection>(), "q" + newState, NodeType.NormalNode));
ModifyAutomaat(reg.left, automaton, stateCounter, leftState, newState); //handle left side of the dot
ModifyAutomaat(reg.right, automaton, stateCounter, newState, rightState); //handle right side of the dot
}
/// <summary>
/// create a NDFA given a RegExp
/// </summary>
/// <param name="reg">the given RegExp</param>
/// <returns> a list of nodes from which to create a NDFA</returns>
public static List <Node> CreateAutomaat(RegExp reg)
{
List <Node> automaton = new List <Node>() //our list of nodes, initialized with a start and end node, they are a given for any automaton
{
new Node(new List <Connection>(), "q0", NodeType.StartNode), //node a
new Node(new List <Connection>(), "q1", NodeType.EndNode) //node b
};
//leftstate is initially the startnode, rightstate the endnode, statecounter keeps track of the last node in automaton
int stateCounter = 1, leftState = 0, rightState = 1;
ModifyAutomaat(reg, automaton, stateCounter, leftState, rightState);
return(automaton);
}
/// <summary>
/// The translation of the plus operator (+) (rule 5)
/// </summary>
/// <param name="reg">the regular expression created with the RegExp class</param>
/// <param name="automaton">the NDFA</param>
/// <param name="stateCounter">keeps track of the next state to add</param>
/// <param name="leftState">From state</param>
/// <param name="rightState">To state</param>
public static void Regel5(RegExp reg, List <Node> automaton, int stateCounter, int leftState, int rightState)
{
var newLeftState = stateCounter + 1;
var newRightState = newLeftState + 1;
stateCounter = newRightState;
//add 2 new nodes for the + operator
automaton.Add(new Node(new List <Connection>(), "q" + newLeftState, NodeType.NormalNode)); //node c
automaton.Add(new Node(new List <Connection>(), "q" + newRightState, NodeType.NormalNode)); //node d
automaton[leftState].AddConnection(new Connection('ϵ', automaton[newLeftState])); //from a to c
automaton[newRightState].AddConnection(new Connection('ϵ', automaton[rightState])); //from d to b
automaton[newRightState].AddConnection(new Connection('ϵ', automaton[newLeftState])); //from d to c
ModifyAutomaat(reg.left, automaton, stateCounter, newLeftState, newRightState); //a plus operator has no right side
}
/// <summary>
/// The translation of the star operator (*) (rule 6)
/// </summary>
/// <param name="reg">the regular expression created with the RegExp class</param>
/// <param name="automaton">the NDFA</param>
/// <param name="stateCounter">keeps track of the next state to add</param>
/// <param name="leftState">From state</param>
/// <param name="rightState">To state</param>
public static void Regel6(RegExp reg, List <Node> automaton, int stateCounter, int leftState, int rightState)
{
var newLeftState = stateCounter + 1;
var newRightState = newLeftState + 1;
stateCounter = newRightState;
automaton.Add(new Node(new List <Connection>(), "q" + newLeftState, NodeType.NormalNode)); //node c
automaton.Add(new Node(new List <Connection>(), "q" + newRightState, NodeType.NormalNode)); //node d
automaton[leftState].AddConnection(new Connection('ϵ', automaton[rightState])); //from a to b
automaton[leftState].AddConnection(new Connection('ϵ', automaton[newLeftState])); //from a to c
automaton[newRightState].AddConnection(new Connection('ϵ', automaton[rightState])); //from d to b
automaton[newRightState].AddConnection(new Connection('ϵ', automaton[newLeftState])); //from d to c
//rule 6 has no right state (*) so we only need to check the left state
ModifyAutomaat(reg.left, automaton, stateCounter, newLeftState, newRightState);
}
/// <summary>
/// The translation of the choice operator (or) (rule 4)
/// </summary>
/// <param name="reg">the regular expression created with the RegExp class</param>
/// <param name="automaton">the NDFA</param>
/// <param name="stateCounter">keeps track of the next state to add</param>
/// <param name="leftState">From state</param>
/// <param name="rightState">To state</param>
public static void Regel4(RegExp reg, List <Node> automaton, int stateCounter, int leftState, int rightState)
{
//the first path to handle (left side)
var newLeftState = stateCounter + 1;
var newRightState = newLeftState + 1;
stateCounter = newRightState;
//node c, add a new node for the or left side(the first epsilon)
automaton.Add(new Node(new List <Connection>(), "q" + newLeftState, NodeType.NormalNode));
//node d, the new node has a connection to automaton[rightState] with epsilon (the last epsilon)
automaton.Add(new Node(new List <Connection>()
{
new Connection('ϵ', automaton[rightState])
}, "q" + newRightState, NodeType.NormalNode)); //from d to b
automaton[leftState].AddConnection(new Connection('ϵ', automaton[newLeftState])); //from a to c
ModifyAutomaat(reg.left, automaton, stateCounter, newLeftState, newRightState); //handle left side of the or
//there are 2 paths to handle, this handles the second one (right side)
newLeftState = stateCounter + 1;
newRightState = newLeftState + 1;
stateCounter = newRightState;
//node e, add a new node for the or right side (the first epsilon)
automaton.Add(new Node(new List <Connection>(), "q" + newLeftState, NodeType.NormalNode));
//node f, the new node has a connection to automaton[rightState] with epsilon (the last epsilon)
automaton.Add(new Node(new List <Connection>()
{
new Connection('ϵ', automaton[rightState])
}, "q" + newRightState, NodeType.NormalNode)); //from f to b
automaton[leftState].AddConnection(new Connection('ϵ', automaton[newLeftState])); //from a to e
ModifyAutomaat(reg.right, automaton, stateCounter, newLeftState, newRightState); //handle right side of the or
}
public void Regexparse(string s)
{
Console.WriteLine("entered string: " + s);
RegexTester tester;
try
{
tester = new RegexTester(s);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
return;
}
string answer = new String(s.Distinct().ToArray());
answer = new String(answer.Where(Char.IsLetter).ToArray());
List <string> strings = GenerateStrings.GenerateString(5, answer);
RegExp exp = RegexParser.parse(s);
List <Node> ndfa = Thompson.CreateAutomaat(exp);
NDFA NDFAregularexpression = new NDFA(new List <Node>()
{
ndfa[0]
}, ndfa);
List <string> regexcorrect = tester.geefTaalTotN(5, answer);
List <string> regexincorrect = tester.geefFoutieveTaalTotN(5, answer);
CreateGraph(NDFAregularexpression.Nodes, "REGEX_NDFA");
DFA DFAregularexpression = NDFAtoDFA.ToDFA2(NDFAregularexpression);
CreateGraph(DFAregularexpression.Nodes, "REGEX_DFA");
NDFA Reverse = DFAReverse.Reverse2(DFAregularexpression);
CreateGraph(Reverse.Nodes, "REGEX_DFA_Reverse");
Console.WriteLine("-------- Correct words Contains --------");
foreach (String item in regexcorrect)
{
Console.WriteLine(item);
}
Console.WriteLine("-------- incorrect words --------");
foreach (String item in regexincorrect)
{
Console.WriteLine(item);
}
Console.WriteLine("-------- regex/ndfa/dfa/ndfa Reversed --------");
foreach (string item in strings)
{
Console.WriteLine(tester.Check(item));
Console.WriteLine(NDFAregularexpression.Check(item));
Console.WriteLine(DFAregularexpression.Check(item));
Console.WriteLine("reverse " + Reverse.Check(item));
}
}
public void HardcodedExamples()
{
List <string> strings = GenerateStrings.GenerateString(5, "ab");
#region DFA
//------------------------------- DFA -------------------------------
Console.WriteLine("---------- DFA -------------");
Console.WriteLine("------- hardcoded ----------");
Console.WriteLine("---- begins with babaa -----");
List <Node> DFA_BWB_ABAA_Nodes = new List <Node>()
{
new Node("q0", NodeType.StartNode),
new Node("q1", NodeType.NormalNode),
new Node("q2", NodeType.NormalNode),
new Node("q3", NodeType.NormalNode),
new Node("q4", NodeType.NormalNode),
new Node("q5", NodeType.EndNode),
new Node("q6", NodeType.NormalNode)
};
DFA_BWB_ABAA_Nodes[0].AddConnections(new List <Connection>()
{
new Connection('b', DFA_BWB_ABAA_Nodes[1]),
new Connection('a', DFA_BWB_ABAA_Nodes[6])
});
DFA_BWB_ABAA_Nodes[1].AddConnections(new List <Connection>()
{
new Connection('b', DFA_BWB_ABAA_Nodes[6]),
new Connection('a', DFA_BWB_ABAA_Nodes[2])
});
DFA_BWB_ABAA_Nodes[2].AddConnections(new List <Connection>()
{
new Connection('b', DFA_BWB_ABAA_Nodes[3]),
new Connection('a', DFA_BWB_ABAA_Nodes[6])
});
DFA_BWB_ABAA_Nodes[3].AddConnections(new List <Connection>()
{
new Connection('b', DFA_BWB_ABAA_Nodes[6]),
new Connection('a', DFA_BWB_ABAA_Nodes[4])
});
DFA_BWB_ABAA_Nodes[4].AddConnections(new List <Connection>()
{
new Connection('b', DFA_BWB_ABAA_Nodes[6]),
new Connection('a', DFA_BWB_ABAA_Nodes[5])
});
DFA_BWB_ABAA_Nodes[5].AddConnections(new List <Connection>()
{
new Connection('b', DFA_BWB_ABAA_Nodes[5]),
new Connection('a', DFA_BWB_ABAA_Nodes[5])
});
DFA_BWB_ABAA_Nodes[6].AddConnections(new List <Connection>()
{
new Connection('b', DFA_BWB_ABAA_Nodes[6]),
new Connection('a', DFA_BWB_ABAA_Nodes[6])
});
DFA BeginsWithBABAA = new DFA(DFA_BWB_ABAA_Nodes[0], DFA_BWB_ABAA_Nodes);
foreach (string item in strings)
{
Console.WriteLine(BeginsWithBABAA.Check(item));
}
CreateGraph(DFA_BWB_ABAA_Nodes, "DFA_BWBABAA");
Console.WriteLine("---- starts with abb or ends with baab -----");
List <Node> DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes = new List <Node>()
{
new Node("q0", NodeType.StartNode),
new Node("q1", NodeType.NormalNode),
new Node("q2", NodeType.NormalNode),
new Node("q3", NodeType.EndNode),
new Node("q4", NodeType.NormalNode),
new Node("q5", NodeType.NormalNode),
new Node("q6", NodeType.NormalNode),
new Node("q7", NodeType.NormalNode),
new Node("q8", NodeType.EndNode)
};
DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[0].AddConnections(new List <Connection>()
{
new Connection('a', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[1]),
new Connection('b', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[4])
});
DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[1].AddConnections(new List <Connection>()
{
new Connection('a', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[6]),
new Connection('b', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[2])
});
DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[2].AddConnections(new List <Connection>()
{
new Connection('a', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[6]),
new Connection('b', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[3])
});
DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[3].AddConnections(new List <Connection>()
{
new Connection('a', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[3]),
new Connection('b', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[3])
});
DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[4].AddConnections(new List <Connection>()
{
new Connection('a', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[4]),
new Connection('b', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[5])
});
DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[5].AddConnections(new List <Connection>()
{
new Connection('a', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[6]),
new Connection('b', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[5])
});
DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[6].AddConnections(new List <Connection>()
{
new Connection('a', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[7]),
new Connection('b', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[5])
});
DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[7].AddConnections(new List <Connection>()
{
new Connection('a', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[4]),
new Connection('b', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[8])
});
DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[8].AddConnections(new List <Connection>()
{
new Connection('a', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[4]),
new Connection('b', DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[5])
});
DFA StartsWithABBorEndsWithBAAB = new DFA(DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes[0], DFA_STARTW_ABB_OR_ENDSW_BAAB_Nodes);
foreach (string item in strings)
{
Console.WriteLine(StartsWithABBorEndsWithBAAB.Check(item));
}
CreateGraph(StartsWithABBorEndsWithBAAB.Nodes, "DFA_STARTWABBORENDSWBAAB");
#endregion
#region HopCroft
List <Node> HopCraftNodes = new List <Node>()
{
new Node("q0", NodeType.StartNode),
new Node("q1", NodeType.NormalNode),
new Node("q2", NodeType.EndNode),
new Node("q3", NodeType.NormalNode),
new Node("q4", NodeType.NormalNode)
};
HopCraftNodes[0].AddConnections(new List <Connection>()
{
new Connection('a', HopCraftNodes[1]),
new Connection('b', HopCraftNodes[2])
});
HopCraftNodes[1].AddConnections(new List <Connection>()
{
new Connection('a', HopCraftNodes[3]),
new Connection('b', HopCraftNodes[0])
});
HopCraftNodes[2].AddConnections(new List <Connection>()
{
new Connection('a', HopCraftNodes[2]),
new Connection('b', HopCraftNodes[4])
});
HopCraftNodes[3].AddConnections(new List <Connection>()
{
new Connection('a', HopCraftNodes[2]),
new Connection('b', HopCraftNodes[1])
});
HopCraftNodes[4].AddConnections(new List <Connection>()
{
new Connection('a', HopCraftNodes[2]),
new Connection('b', HopCraftNodes[1])
});
DFA HopCraft = new DFA(HopCraftNodes[0], HopCraftNodes);
HopCraft = HopCroft.MinimizeHopCroft(HopCraft);
CreateGraph(HopCraft.Nodes, "DFA_HopCroft");
#endregion
#region NDFA
//------------------------------- NDFA -------------------------------
Console.WriteLine("---------- NDFA ------------");
Console.WriteLine("---- Contains aa or bb -----");
List <Node> NDFA_C_AAoBB_Nodes = new List <Node>()
{
new Node("q0", NodeType.StartNode),
new Node("q1", NodeType.NormalNode),
new Node("q2", NodeType.NormalNode),
new Node("q3", NodeType.EndNode),
};
NDFA_C_AAoBB_Nodes[0].AddConnections(new List <Connection>()
{
new Connection('b', NDFA_C_AAoBB_Nodes[0]),
new Connection('a', NDFA_C_AAoBB_Nodes[0]),
new Connection('b', NDFA_C_AAoBB_Nodes[2]),
new Connection('a', NDFA_C_AAoBB_Nodes[1])
});
NDFA_C_AAoBB_Nodes[1].AddConnections(new List <Connection>()
{
new Connection('a', NDFA_C_AAoBB_Nodes[3]),
new Connection('b', NDFA_C_AAoBB_Nodes[0])
});
NDFA_C_AAoBB_Nodes[2].AddConnections(new List <Connection>()
{
new Connection('b', NDFA_C_AAoBB_Nodes[3]),
new Connection('a', NDFA_C_AAoBB_Nodes[0])
});
NDFA_C_AAoBB_Nodes[3].AddConnections(new List <Connection>()
{
new Connection('b', NDFA_C_AAoBB_Nodes[3]),
new Connection('a', NDFA_C_AAoBB_Nodes[3])
});
NDFA ContainsAAorBB = new NDFA(new List <Node>()
{
NDFA_C_AAoBB_Nodes[0]
}, NDFA_C_AAoBB_Nodes);
foreach (string item in strings)
{
Console.WriteLine(ContainsAAorBB.Check(item));
}
CreateGraph(NDFA_C_AAoBB_Nodes, "NDFA_CAAoBB");
#endregion
#region regex
//---------------------------- regex -------------------------------
List <string> regexstrings = GenerateStrings.GenerateString(5, "abc");
Console.WriteLine("---------- regex ------------");
Console.WriteLine("--------- (a|bc)* ----------");
RegexTester regexTester = new RegexTester(@"(a|bc)*");
foreach (string item in regexstrings)
{
Console.WriteLine(regexTester.Check(item));
}
Console.WriteLine("--------- wrong ----------");
List <string> foutievetaal = regexTester.geefFoutieveTaalTotN(5, "abc");
foreach (string item in foutievetaal)
{
Console.WriteLine(regexTester.Check(item));
}
Console.WriteLine("--------- correct ----------");
List <string> correctetaal = regexTester.geefTaalTotN(5, "abc");
foreach (string item in correctetaal)
{
Console.WriteLine(regexTester.Check(item));
}
#endregion
#region GenerateBeginsWith
Console.WriteLine("-------- Generated --------");
List <Node> BeginsWithBABAANodes = GenerateDFA.GenerateDFABeginsWith("babaa", "ab");
Node beginsstartnode = null;
foreach (Node item in BeginsWithBABAANodes)
{
if (item.nodeType == NodeType.StartNode)
{
beginsstartnode = item;
}
}
DFA GEN_BeginsWithBABAA = new DFA(beginsstartnode, BeginsWithBABAANodes);
foreach (string item in strings)
{
Console.WriteLine(GEN_BeginsWithBABAA.Check(item));
}
List <String> correctWordsbw = GEN_BeginsWithBABAA.geefTaalTotN(5, "ab");
Console.WriteLine("-------- Correct words BeginsWithBABAA --------");
foreach (String s in correctWordsbw)
{
Console.WriteLine(s);
}
List <String> inCorrectWordsbw = GEN_BeginsWithBABAA.geefFoutieveTaalTotN(5, "ab");
Console.WriteLine("-------- incorrect words BeginsWithBABAA --------");
foreach (String s in inCorrectWordsbw)
{
Console.WriteLine(s);
}
CreateGraph(GEN_BeginsWithBABAA.Nodes, "GEN_DFABWBABAA");
#endregion
#region GenerateEndsWith
List <Node> EndsWithBABAANodes = GenerateDFA.GenerateDFAEndsWith("aabab", "ab");
Node EndsWithstartnode = null;
foreach (Node item in EndsWithBABAANodes)
{
if (item.nodeType == NodeType.StartNode)
{
EndsWithstartnode = item;
}
}
DFA GEN_EndsWithBABAA = new DFA(EndsWithstartnode, EndsWithBABAANodes);
foreach (string item in strings)
{
Console.WriteLine(GEN_EndsWithBABAA.Check(item));
}
List <String> correctWordsew = GEN_EndsWithBABAA.geefTaalTotN(5, "ab");
Console.WriteLine("-------- Correct words EndsWithAABAB --------");
foreach (String s in correctWordsew)
{
Console.WriteLine(s);
}
List <String> inCorrectWordsew = GEN_EndsWithBABAA.geefFoutieveTaalTotN(5, "ab");
Console.WriteLine("-------- incorrect words EndsWithAABAB --------");
foreach (String s in inCorrectWordsew)
{
Console.WriteLine(s);
}
CreateGraph(GEN_EndsWithBABAA.Nodes, "GEN_DFAEWAABAB");
#endregion
#region Contains
List <Node> ContainsBABAANodes = GenerateDFA.GenerateDFAContains("bab", "ab");
Node Containsstartnode = null;
foreach (Node item in ContainsBABAANodes)
{
if (item.nodeType == NodeType.StartNode)
{
Containsstartnode = item;
}
}
DFA GEN_ContainsBABAA = new DFA(Containsstartnode, ContainsBABAANodes);
foreach (string item in strings)
{
Console.WriteLine(GEN_ContainsBABAA.Check(item));
}
List <String> correctWordsc = GEN_ContainsBABAA.geefTaalTotN(5, "ab");
Console.WriteLine("-------- Correct words ContainsBAB --------");
foreach (String s in correctWordsc)
{
Console.WriteLine(s);
}
List <String> inCorrectWordsc = GEN_ContainsBABAA.geefFoutieveTaalTotN(5, "ab");
Console.WriteLine("-------- incorrect words ContainsBAB --------");
foreach (String s in inCorrectWordsc)
{
Console.WriteLine(s);
}
CreateGraph(GEN_ContainsBABAA.Nodes, "GEN_DFAEWBAB");
#endregion
#region Regex -> NDFA
Console.WriteLine("---------- Regular expression tester with Regex and Thompson ------------");
Console.WriteLine("---------- (a|bc)* -----------");
regexTester = new RegexTester(@"(a|bc)*");
RegExp reg = new RegExp("a").or(new RegExp("b").dot(new RegExp("c"))).star();
List <Node> ndfa = Thompson.CreateAutomaat(reg);
NDFA NDFAregularexpression2 = new NDFA(new List <Node>()
{
ndfa[0]
}, ndfa);
foreach (string item in strings)
{
Console.WriteLine(NDFAregularexpression2.Check(item));
Console.WriteLine("Regex test: " + regexTester.Check(item));
}
CreateGraph(NDFAregularexpression2.Nodes, "NDFA_RegexThompsonToNDFA");
#endregion
#region NDFAtoDFA
//--------------------------- NDFA -> DFA ---------------------------
Console.WriteLine("---- test NDFA to DFA -----");
Console.WriteLine("---------- NDFA -----------");
List <Node> NDFATODFA = new List <Node>()
{
new Node("q1", NodeType.StartNode),
new Node("q2", NodeType.EndNode),
new Node("q3", NodeType.EndNode),
new Node("q4", NodeType.NormalNode),
new Node("q5", NodeType.NormalNode)
};
NDFATODFA[0].AddConnections(new List <Connection>()
{
new Connection('b', NDFATODFA[1]),
new Connection('a', NDFATODFA[1]),
new Connection('b', NDFATODFA[2]),
});
NDFATODFA[1].AddConnections(new List <Connection>()
{
new Connection('a', NDFATODFA[2]),
new Connection('ϵ', NDFATODFA[3]),
new Connection('b', NDFATODFA[3])
});
NDFATODFA[2].AddConnections(new List <Connection>()
{
new Connection('a', NDFATODFA[1])
});
NDFATODFA[3].AddConnections(new List <Connection>()
{
new Connection('a', NDFATODFA[4]),
new Connection('a', NDFATODFA[1])
});
NDFATODFA[4].AddConnections(new List <Connection>()
{
new Connection('b', NDFATODFA[4]),
new Connection('ϵ', NDFATODFA[2])
});
NDFA TESTNDFATODFA = new NDFA(new List <Node>()
{
NDFATODFA[0]
}, NDFATODFA);
CreateGraph(TESTNDFATODFA.Nodes, "NDFA_NDFAtoDFA");
foreach (string item in strings)
{
//Console.WriteLine(TESTNDFATODFA.Check(item));
}
Console.WriteLine("----------- DFA -----------");
DFA TESTDFA = NDFAtoDFA.ToDFA2(TESTNDFATODFA);
CreateGraph(TESTDFA.Nodes, "DFA_NDFAtoDFA");
foreach (string item in strings)
{
Console.WriteLine(TESTNDFATODFA.Check(item));
Console.WriteLine(TESTDFA.Check(item));
}
#endregion
#region Reverse
Console.WriteLine("---- (NDFA) reverse begins with babaa -----");
NDFA reversedBABAA = DFAReverse.Reverse2(BeginsWithBABAA);
foreach (string item in strings)
{
Console.WriteLine(reversedBABAA.Check(item));
}
CreateGraph(reversedBABAA.Nodes, "ReversedBABAA");
#endregion
}
/// <summary>
/// A basic parser that rewrites strings into a RegExp object.
/// </summary>
/// <param name="text">The text to create a RegExp from</param>
/// <returns>a RegExp based on the text</returns>
public static RegExp parse(string text)
{
RegExp regex = new RegExp(); //the output RegExp object
Mode currentMode = 0; //no dot or or found yet
List <Char> chars = new List <char>(); //memory of all found characters, needed for ) and or
//parse each letter
foreach (char c in text.ToCharArray())
{
//What does the letter mean for the conversion?
switch (c)
{
case '(': //can be ignored
break;
case ')': //handle all leftover characters since we are going up in depth
RegExp reg = new RegExp();
foreach (Char ch in chars)
{
if (reg.left == null && reg.right == null && reg.terminals == "")
{
reg = new RegExp(ch.ToString()); //if it's the first charachter
}
else
{
reg = reg.dot(new RegExp(ch.ToString())); //there was atleast 1 character before this one
}
}
chars.Clear(); //chars are used, array can be cleard
regex = regex.or(reg);
currentMode = 0; //or used to set mode back to nothing
break;
case '|': //or detected
currentMode = Mode.or;
break;
case '+': //+ detected
regex = regex.plus();
break;
case '*': //star detected
regex = regex.star();
break;
case '.': //dot detected
currentMode = Mode.dot;
break;
default: //no special character detected
switch (currentMode) //the mode is important for handling the dot, or and one
{
case Mode.nothing:
if (regex.left == null && regex.right == null && regex.terminals == "")
{
regex = new RegExp(c.ToString()); //if it's the first charachter
}
else
{
regex = regex.dot(new RegExp(c.ToString())); //there was atleast 1 character before this one
}
break;
case Mode.or:
chars.Add(c); //an or expects all characters in one RegExp object, add them to an array first
break;
case Mode.dot:
regex = regex.dot(new RegExp(c.ToString()));
break;
}
break;
}
}
if (chars.Count != 0) //makes sure a Regexp object is properly closed off.
{
RegExp reg = new RegExp();
foreach (Char ch in chars)
{
if (reg.left == null && reg.right == null && reg.terminals == "")
{
reg = new RegExp(ch.ToString()); //if it's the first charachter
}
else
{
reg = reg.dot(new RegExp(ch.ToString())); //there was atleast 1 character before this one
}
}
regex = regex.or(reg);
}
return(regex);
}
