Known caveats (TGPD: The GLADOS Project Documentation)

Lexing Error Printing : We are aware that Megaparsec does not always display clear or accurate error messages in some cases. This issue is due to our current lexing implementation rather than Megaparsec itself, and should be fixed soon or later.
Parsing Input : The parser currently does not validate its input and fully relies on the lexer to always produce correct and consistent tokens. While this works for now, it could lead to potential issues in the future.