/**
* Finds a unique character transition if one exists. The
* transition must be the only matching single character
* transition and no other transitions may reach the same
* state.
*
* @param ch the character to search for
*
* @return the unique transition state found, or
* null if not found
*/
private NFAState FindUniqueCharTransition(char ch)
{
NFATransition res = null;
NFATransition trans;
for (int i = 0; i < outgoing.Length; i++)
{
trans = outgoing[i];
if (trans.Match(ch) && trans is NFACharTransition)
{
if (res != null)
{
return(null);
}
res = trans;
}
}
for (int i = 0; res != null && i < outgoing.Length; i++)
{
trans = outgoing[i];
if (trans != res && trans.state == res.state)
{
return(null);
}
}
return((res == null) ? null : res.state);
}
/**
* Adds a new outgoing transition.
*
* @param trans the transition to add
*
* @return the transition target state
*/
public NFAState AddOut(NFATransition trans)
{
Array.Resize(ref outgoing, outgoing.Length + 1);
outgoing[outgoing.Length - 1] = trans;
if (trans is NFAEpsilonTransition)
{
epsilonOut = true;
}
return(trans.state);
}
/**
* Adds a new incoming transition.
*
* @param trans the transition to add
*/
public void AddIn(NFATransition trans)
{
Array.Resize(ref incoming, incoming.Length + 1);
incoming[incoming.Length - 1] = trans;
}