public virtual string ToDot()
{
StringBuilder b = new StringBuilder("digraph CompiledAutomaton {\n");
b.Append(" rankdir = LR;\n");
int initial = RunAutomaton.InitialState;
for (int i = 0; i < sortedTransitions.Length; i++)
{
b.Append(" ").Append(i);
if (RunAutomaton.IsAccept(i))
{
b.Append(" [shape=doublecircle,label=\"\"];\n");
}
else
{
b.Append(" [shape=circle,label=\"\"];\n");
}
if (i == initial)
{
b.Append(" initial [shape=plaintext,label=\"\"];\n");
b.Append(" initial -> ").Append(i).Append("\n");
}
for (int j = 0; j < sortedTransitions[i].Length; j++)
{
b.Append(" ").Append(i);
sortedTransitions[i][j].AppendDot(b);
}
}
return b.Append("}\n").ToString();
}
//private static final boolean DEBUG = BlockTreeTermsWriter.DEBUG;
private BytesRef AddTail(int state, BytesRef term, int idx, int leadLabel)
{
// Find biggest transition that's < label
// TODO: use binary search here
Transition maxTransition = null;
foreach (Transition transition in sortedTransitions[state])
{
if (transition.min < leadLabel)
{
maxTransition = transition;
}
}
if (Debugging.AssertsEnabled)
{
Debugging.Assert(maxTransition != null);
}
// Append floorLabel
int floorLabel;
if (maxTransition.max > leadLabel - 1)
{
floorLabel = leadLabel - 1;
}
else
{
floorLabel = maxTransition.max;
}
if (idx >= term.Bytes.Length)
{
term.Grow(1 + idx);
}
//if (DEBUG) System.out.println(" add floorLabel=" + (char) floorLabel + " idx=" + idx);
term.Bytes[idx] = (byte)floorLabel;
state = maxTransition.to.Number;
idx++;
// Push down to last accept state
while (true)
{
Transition[] transitions = sortedTransitions[state];
if (transitions.Length == 0)
{
if (Debugging.AssertsEnabled)
{
Debugging.Assert(RunAutomaton.IsAccept(state));
}
term.Length = idx;
//if (DEBUG) System.out.println(" return " + term.utf8ToString());
return(term);
}
else
{
// We are pushing "top" -- so get last label of
// last transition:
if (Debugging.AssertsEnabled)
{
Debugging.Assert(transitions.Length != 0);
}
Transition lastTransition = transitions[transitions.Length - 1];
if (idx >= term.Bytes.Length)
{
term.Grow(1 + idx);
}
//if (DEBUG) System.out.println(" push maxLabel=" + (char) lastTransition.max + " idx=" + idx);
term.Bytes[idx] = (byte)lastTransition.max;
state = lastTransition.to.Number;
idx++;
}
}
}
/// <summary>
/// Finds largest term accepted by this Automaton, that's
/// <= the provided input term. The result is placed in
/// output; it's fine for output and input to point to
/// the same <see cref="BytesRef"/>. The returned result is either the
/// provided output, or <c>null</c> if there is no floor term
/// (ie, the provided input term is before the first term
/// accepted by this <see cref="Automaton"/>).
/// </summary>
public virtual BytesRef Floor(BytesRef input, BytesRef output)
{
output.Offset = 0;
//if (DEBUG) System.out.println("CA.floor input=" + input.utf8ToString());
int state = RunAutomaton.InitialState;
// Special case empty string:
if (input.Length == 0)
{
if (RunAutomaton.IsAccept(state))
{
output.Length = 0;
return output;
}
else
{
return null;
}
}
IList<int> stack = new List<int>();
int idx = 0;
while (true)
{
int label = ((sbyte)input.Bytes[input.Offset + idx]) & 0xff;
int nextState = RunAutomaton.Step(state, label);
//if (DEBUG) System.out.println(" cycle label=" + (char) label + " nextState=" + nextState);
if (idx == input.Length - 1)
{
if (nextState != -1 && RunAutomaton.IsAccept(nextState))
{
// Input string is accepted
if (idx >= output.Bytes.Length)
{
output.Grow(1 + idx);
}
output.Bytes[idx] = (byte)label;
output.Length = input.Length;
//if (DEBUG) System.out.println(" input is accepted; return term=" + output.utf8ToString());
return output;
}
else
{
nextState = -1;
}
}
if (nextState == -1)
{
// Pop back to a state that has a transition
// <= our label:
while (true)
{
Transition[] transitions = sortedTransitions[state];
if (transitions.Length == 0)
{
if (Debugging.AssertsEnabled) Debugging.Assert(RunAutomaton.IsAccept(state));
output.Length = idx;
//if (DEBUG) System.out.println(" return " + output.utf8ToString());
return output;
}
else if (label - 1 < transitions[0].min)
{
if (RunAutomaton.IsAccept(state))
{
output.Length = idx;
//if (DEBUG) System.out.println(" return " + output.utf8ToString());
return output;
}
// pop
if (stack.Count == 0)
{
//if (DEBUG) System.out.println(" pop ord=" + idx + " return null");
return null;
}
else
{
state = stack[stack.Count - 1];
stack.RemoveAt(stack.Count - 1);
idx--;
//if (DEBUG) System.out.println(" pop ord=" + (idx+1) + " label=" + (char) label + " first trans.min=" + (char) transitions[0].min);
label = input.Bytes[input.Offset + idx] & 0xff;
}
}
else
{
//if (DEBUG) System.out.println(" stop pop ord=" + idx + " first trans.min=" + (char) transitions[0].min);
break;
}
}
//if (DEBUG) System.out.println(" label=" + (char) label + " idx=" + idx);
return AddTail(state, output, idx, label);
}
else
{
if (idx >= output.Bytes.Length)
{
output.Grow(1 + idx);
}
output.Bytes[idx] = (byte)label;
stack.Add(state);
state = nextState;
idx++;
}
}
}