/// <summary>
/// Creates an instance of a DFA state object from the specified parameters.
/// </summary>
public DfaState(ushort?smallestAcceptState, ICollection <NfaState> nfaStates, int dfaId)
{
DfaId = dfaId;
SmallestAcceptState = smallestAcceptState;
NfaStates = new HashSet <NfaState>(nfaStates);
EvaluationNode = new RegExEvaluationNode {
Id = dfaId
};
}
private bool NodeIsReferenced(RegExEvaluationNode node)
{
return(_dfaStates.Exists(s => s.EvaluationNode.Values.Contains(node)));
}
private void GenerateCode(GeneratorScope scope, RegExEvaluationNode node)
{
var dfa = _dfaStates[node.Id];
var currentState = dfa.SmallestAcceptState;
#if DIAGNOSTICS
Console.WriteLine($"Code generation for of state {dfa.DfaId}:");
foreach (var range in node)
{
Console.WriteLine($" range {range.Key.Min}-{range.Key.Max} {range.Value?.Id} {range.Value?.AcceptAction}");
}
#endif
var points = new SortedDictionary <uint, RegExEvaluationNode>();
RegExEvaluationNode lastValue = null;
uint lastSuccessor = 0;
foreach (var pair in node)
{
if ((pair.Value == lastValue) && (lastSuccessor == pair.Key.Min))
{
points.Remove(lastSuccessor);
}
else if (lastSuccessor < pair.Key.Min)
{
points.Add(pair.Key.Min, null);
}
lastSuccessor = pair.Key.Max + 1;
points.Add(lastSuccessor, pair.Value);
lastValue = pair.Value;
}
if (lastSuccessor == char.MaxValue + 1)
{
points.Remove(lastSuccessor);
}
else
{
lastValue = null;
}
#if DIAGNOSTICS
Console.WriteLine("Points:");
foreach (var pair in points)
{
Console.WriteLine(" point {0} -> {1}", pair.Key, pair.Value != null ? $"{pair.Value.Id} ({pair.Value.AcceptAction})" : string.Empty);
}
#endif
var accept = node.AcceptAction.HasValue ? $" (accepts to {node.AcceptAction.Value})" : string.Empty;
scope.WriteLine("/*");
scope.WriteLine(" * DFA STATE {0}{1}", node.Id, accept);
foreach (var map in node)
{
scope.WriteLine(" * {0} -> {1}", map.Key, map.Value.Id);
}
scope.WriteLine(" */");
if ((node.Id > 0) || NodeIsReferenced(node))
{
scope.SetLabel(scope.StateLabel(node.Id));
}
if (node.AcceptAction.HasValue && !(node.AcceptAction > currentState))
{
scope.MarkPos();
if (node.Count > 0)
{
scope.IncrementPos(scope.AcceptLabel(node.AcceptAction), node.Id == 0);
}
}
else
{
if (node.Count > 0)
{
scope.IncrementPos(scope.AcceptLabel(currentState), node.Id == 0);
}
}
var pointList = points.ToList();
if ((pointList.Count == 0) && (node.Count == 0))
{
scope.Goto(scope.AcceptLabel(currentState));
}
else
{
SubGenerate(scope, pointList, 0, points.Count - 1, lastValue, currentState);
}
}
private void SubGenerate(GeneratorScope scope, IReadOnlyList <KeyValuePair <uint, RegExEvaluationNode> > nodes, int a, int b, RegExEvaluationNode target, ushort?currentState)
{
if (a > b)
{
scope.Goto(target == null ? scope.AcceptLabel(currentState) : scope.StateLabel(target.Id));
}
else
{
var m = (a + b) / 2;
var pair = nodes[m];
scope.IfBegin(pair.Key, m - a);
SubGenerate(scope.Indent(), nodes, a, m - 1, pair.Value, currentState);
scope.IfEnd(m - a);
SubGenerate(scope, nodes, m + 1, b, target, currentState);
}
}
