/// <summary>
/// Matches a given token sequence into one or more Tokens.
/// </summary>
/// <param name="sequence">
/// The token sequence (possibly) containing tokens.
/// </param>
private void MatchTokens(SequenceNode node)
{
TokenSequence discarded = new TokenSequence();
TokenSequence accepted = new TokenSequence();
SequenceNode acceptedNode = new SequenceNode(accepted, view);
SequenceNode discardedNode = new SequenceNode(discarded, view);
TokenSequence sequence = node.Sequence;
node.AddChildSequence(acceptedNode);
foreach (Token t in sequence)
{
accepted.Append(t);
}
NodeBeingProcessedInvoker(node);
SuspendByStep();
bool found = false;
Token foundToken = null;
bool discardedNodeAdded = false;
MessageLogSentInvoker("===== Tratando la secuencia {0} =====",
node.NodeName);
while (accepted.Count > 0 && !found)
{
foreach (LexicalRule rule in lexicalRules)
{
found = rule.Match(accepted, out foundToken);
MessageLogSentInvoker("¿La regla «{0}» acepta la secuencia ({1})?: {2}",
rule.Name,
accepted.ToString(),
found?"Sí":"No");
SequenceBeingMatchedInvoker(foundToken, rule, found);
SuspendByStep();
if (found)
{
// We search no more.
break;
}
Thread.Sleep(50);
}
// We check if a token was found
if (!found)
{
// We remove the token from the input sequence and add it
// at the beggining of the discarded set.
int lastIndex = accepted.Count - 1;
if (!discardedNodeAdded)
{
// If we haven't done so, we add the discarded sequence.
node.AddChildSequence(discardedNode);
discardedNodeAdded = true;
}
this.MatchingFailedInvoker();
MessageLogSentInvoker("Se elimina el último símbolo de la secuencia {0} para seguir probando.",
accepted.ToString());
discarded.Prepend(accepted[lastIndex]);
accepted.RemoveAt(lastIndex);
}
else
{
// We found a token, so we stop searching and add
// the token to the result.
acceptedNode.FoundToken = foundToken;
}
}
if (found && discarded.Count > 0)
{
MessageLogSentInvoker("Se tratará la secuencia de símbolos descartados.");
// We follow the recursive path.
MatchTokens(discardedNode);
}
else if (found && discarded.Count == 0)
{
// Only one token was found, we assimilate the acceptedNode
// with its parent.
node.FoundToken = foundToken;
node.RemoveSequenceChildren();
}
else
{
// If nothing was found, we remove the children.
node.RemoveSequenceChildren();
MessageLogSentInvoker("No se pudo reconocer la secuencia {0}.",
node.Sequence.ToString());
}
StepDoneInvoker();
SuspendByNode();
}