Improve parsers performance

**Problem**
When working with lib, the error messages could be more descriptive.

**Suggestion**
Improve error handling and add detailed error messages.

**Context**
This would help with debugging and maintenance.

Start by locating the parser code under lib and reproduce the current error cases described by the issue. Define the affected parser paths and verify that errors become more descriptive while checking the performance concern in the title; the issue does not name specific files, tests, or completion criteria.

Written by the indexing model from the issue text.