public void RollbackCursor(TokenExtractorCursor cursor)
{
if (cursor.Position < 0 || cursor.Position > _reader.Length - 1)
{
throw new IndexOutOfRangeException();
}
_reader.Position = cursor.Position;
}
public SyntaxTree Parse(TokenExtractor extractor)
{
if (extractor == null)
{
throw new ArgumentNullException(nameof(extractor));
}
TokenExtractorCursor cursor = TokenExtractorCursor.Invalid;
SyntaxTree tree = new SyntaxTree();
// TODO: Mudar para [SyntaxTreeNode]
Token token = null;
try
{
cursor = extractor.SaveCursor();
// TODO: Deve retornar [SyntaxTreeNode]
token = _grammar.RootElement.Eval(extractor);
if (token != null && extractor.EndOfCode)
{
var node = new SyntaxTreeNode(token);
tree.Validate(node);
}
}
catch (Exception ex)
{
if (!TokenExtractorCursor.Invalid.Equals(cursor))
{
try { extractor.RollbackCursor(cursor); }
catch (Exception) { /* QUIET */ }
}
LogException(ex);
}
if (token == null || !tree.IsValid)
{
if (!TokenExtractorCursor.Invalid.Equals(cursor))
{
try { extractor.RollbackCursor(cursor); }
catch (Exception) { /* QUIET */ }
}
}
return(tree);
}
