public RegExpEvaluator(string regexp)
{
infix2postfix = new Infix2PostfixHelper();
automatonConstructor = new ThompsonHelper();
DfaConstructor = new SubsetConstructor();
String expression = infix2postfix.converter(regexp);
Graph final;
automaton = automatonConstructor.getAutomaton(expression, out final);
DfaConstructor = new SubsetConstructor();
DfaAutomaton = DfaConstructor.BuildDfa(automaton, final);
}
public void Add(char theChar, Graph theGraph)
{
HashSet<Graph> newList;
if (trajectories.TryGetValue(theChar, out newList))
{
newList.Add(theGraph);
}
else
{
newList = new HashSet<Graph>();
newList.Add(theGraph);
trajectories.Add(theChar, newList);
}
}
public Graph getAutomaton(string expression, out Graph finalGraph)
{
Graph Start = new Graph();
Graph End = new Graph();
Start.name = getName();
End.isFinalState = true;
expressionStack = new Stack<char>();
foreach (char c in expression)
{
expressionStack.Push(c);
}
Start = doAutomaton(Start, End);
End.name = getName();
finalGraph = End;
return Start;
}
private Graph doAutomaton(Graph start, Graph end)
{
char tempchar;
tempchar = expressionStack.Pop();
switch (tempchar)
{
case 'ä': // suppose s|t
{
Graph NsStart = new Graph();
Graph NsEnd = new Graph();
Graph NtStart = new Graph();
Graph NtEnd = new Graph();
NsStart.name = getName(); //name N(s) automaton
NsEnd.name = getName();
NtStart.name = getName(); //name N(t) automaton
NtEnd.name = getName();
doAutomaton(NtStart, NtEnd); //generate N(t) automaton
doAutomaton(NsStart, NsEnd); //generate N(s) automaton
start.Add('ü', NsStart); //add N(s) as destiny from start
start.Add('ü', NtStart); //add N(t) as destiny from start
NsEnd.Add('ü', end); //add ending node to N(s)
NtEnd.Add('ü', end); //add ending node to N(t)
}
break;
case 'ÿ':
{
Graph middleNode = new Graph();
middleNode.name = getName();
doAutomaton(middleNode, end); //join N(t) with ending node
doAutomaton(start, middleNode); //join N(t) with starting node
}
break;
case 'þ':
{
Graph NsStart = new Graph();
Graph NsEnd = new Graph();
NsStart.name = getName();
NsEnd.name = getName();
doAutomaton(NsStart, NsEnd);
start.Add('ü', NsStart);
NsEnd.Add('ü', NsStart);
NsEnd.Add('ü', end);
start.Add('ü', end);
}
break;
default:
{
start.Add(tempchar, end);
}
break;
}
return start;
}