[Feature Request] Allow unicode identifiers

[soraros]

Review Mojo's priorities

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

What is your request?

Add support for unicode identifiers like in Python 3 (or better, like Swift/Julia).

What is your motivation for this change?

• PEP 3131
• Essential for Python source compatibility
• Important for developers using any non-ASCII language
• Looks good in math formulas, which the target audience (ML researchers, data scientist, etc.) tend to use a lot

Any other details?

No response

[Mogball]

This is essential for emoji identifiers

[soraros]

@Mogball I tried very hard NOT to mention emoji identifiers.

[Mogball]

You can use backticks to escape any identifier, like

fn `🧠`(`😇🥹`: Int):
  print(`😇🥹`)

Is valid. But I agree for Python source compatibility, we should look into unicode identifiers without backticks.

[lattner]

Sure, of course we'll need to support PEP3131