public LabelToolCommand(CommandToolParser.LabelCommandContext context) { if (context.LITERAL().Length < 1) { return; } Address = ProcessNumber(context.LITERAL()[0].GetText()); if (HasSemanticError) { return; } if (context.LITERAL().Length < 2) { return; } var idText = context.LITERAL()[1].GetText(); if (char.IsDigit(idText[0])) { HasSemanticError = true; return; } Symbol = idText; }