/**
* Set the start state for a specific precedence value.
*
* @param precedence The current precedence.
* @param startState The start state corresponding to the specified
* precedence.
*
* @throws IllegalStateException if this is not a precedence DFA.
* @see #isPrecedenceDfa()
*/
public void SetPrecedenceStartState(int precedence, DFAState startState)
{
if (!IsPrecedenceDfa)
{
throw new Exception("Only precedence DFAs may contain a precedence start state.");
}
if (precedence < 0)
{
return;
}
// synchronization on s0 here is ok. when the DFA is turned into a
// precedence DFA, s0 will be initialized once and not updated again
lock (s0)
{
// s0.edges is never null for a precedence DFA
if (precedence >= s0.edges.Length)
{
s0.edges = Arrays.CopyOf(s0.edges, precedence + 1);
}
s0.edges[precedence] = startState;
}
}
internal virtual string GetStateString(DFAState s)
{
if (s == ATNSimulator.ERROR)
{
return("ERROR");
}
int n = s.stateNumber;
string baseStateStr = (s.isAcceptState ? ":" : "") + "s" + n + (s.requiresFullContext ? "^" : "");
if (s.isAcceptState)
{
if (s.predicates != null)
{
return(baseStateStr + "=>" + Arrays.ToString(s.predicates));
}
else
{
return(baseStateStr + "=>" + s.prediction);
}
}
else
{
return(baseStateStr);
}
}
public DFA(DecisionState atnStartState, int decision)
{
this.atnStartState = atnStartState;
this.decision = decision;
this.precedenceDfa = false;
if (atnStartState is StarLoopEntryState && ((StarLoopEntryState)atnStartState).isPrecedenceDecision)
{
this.precedenceDfa = true;
DFAState precedenceState = new DFAState(new ATNConfigSet());
precedenceState.edges = new DFAState[0];
precedenceState.isAcceptState = false;
precedenceState.requiresFullContext = false;
this.s0 = precedenceState;
}
}
/**
* Two {@link DFAState} instances are equal if their ATN configuration sets
* are the same. This method is used to see if a state already exists.
*
* <p>Because the number of alternatives and number of ATN configurations are
* finite, there is a finite number of DFA states that can be processed.
* This is necessary to show that the algorithm terminates.</p>
*
* <p>Cannot test the DFA state numbers here because in
* {@link ParserATNSimulator#addDFAState} we need to know if any other state
* exists that has this exact set of ATN configurations. The
* {@link #stateNumber} is irrelevant.</p>
*/
public override bool Equals(Object o)
{
// compare set of ATN configurations in this set with other
if (this == o)
{
return(true);
}
if (!(o is DFAState))
{
return(false);
}
DFAState other = (DFAState)o;
// TODO (sam): what to do when configs==null?
bool sameSet = this.configSet.Equals(other.configSet);
// System.out.println("DFAState.equals: "+configs+(sameSet?"==":"!=")+other.configs);
return(sameSet);
}
public override string ToString()
{
if (dfa.s0 == null)
{
return(null);
}
StringBuilder buf = new StringBuilder();
if (dfa.states != null)
{
List <DFAState> states = new List <DFAState>(dfa.states.Values);
states.Sort((x, y) => x.stateNumber - y.stateNumber);
foreach (DFAState s in states)
{
int n = s.edges != null ? s.edges.Length : 0;
for (int i = 0; i < n; i++)
{
DFAState t = s.edges[i];
if (t != null && t.stateNumber != int.MaxValue)
{
buf.Append(GetStateString(s));
String label = GetEdgeLabel(i);
buf.Append("-");
buf.Append(label);
buf.Append("->");
buf.Append(GetStateString(t));
buf.Append('\n');
}
}
}
}
string output = buf.ToString();
if (output.Length == 0)
{
return(null);
}
return(output);
}
