[Feature Request] Add compiler warnings (or errors) for usage of inappropriate case

[gryznar]

Review Mojo's priorities

• I have read the roadmap and priorities and I believe this request falls within the priorities.

What is your request?

I would suggest to add warnings (or errors possible to turn off via flag) to the compiler related to usage of inappropriate case in source code (camelCase instead of snake_case and so on)

What is your motivation for this change?

This feature will greatly help to keep entire Mojo codebase consistent and avoid mess as is still in Python (despite PEP8) and which is not fixable because of huge compatibility reasons:

Of course, if compiler will suffer from this additional job, this may be moved to formatting tool, but keeping that in the compiler would have few advantages:

• formater is optional, not everyone will use that, while using compiler is essential
• warning from compiler would point directly, that this should be fixed (feedback from formater may be threaten as suggestions)
• people which come from another language would have information directly without need of using external resources

Rust already has that feature in its compiler, so it is doable :)

Any other details?

As for now this is a noticeable problem. People who start to develop projects in Mojo are not aware that snake_case is only one supported convention. The sooner it will be introduced, the better.