Improve 'cannot contain emoji' error.

[m-ou-se]

Before:

error: identifiers cannot contain emoji: `🦀`
 --> src/main.rs:2:9
  |
2 |     let 🦀 = 1;
  |         ^^

After:

error: Ferris cannot be used as an identifier
 --> src/main.rs:2:9
  |
2 |     let 🦀 = 1;
  |         ^^ help: try using their name instead: `ferris`

r? @estebank

[inquisitivecrystal]

First of all, this is my new favorite PR.

Small editorial comment.

I suggest making "Ferris" lowercase, both to match standard convention and to align it with the structured suggestion. If you disagree, feel free to disregard this.

[camelid]

Ferris is a name, so I think the current capitalization is more accurate ;)

[estebank]

@bors r+

[bors]

📌 Commit 9d535b4 has been approved by estebank

[boehs]

This was widely stopping rust adoption for me, Thank you.

[Be-ing]

First of all, this is my new favorite PR.

I think this pull request may have won the Internet.

[ggangix]

Love it !

[inferrna]

I think we need more bullshit like this. Next step would be including the whole gemoji crate into compiler codebase to be able to name any emoji, not just Ferris only.

[steffahn]

The capitalization in the suggestions seems off when you don’t use it for a variable.

E.g. in a struct name

error: Ferris cannot be used as an identifier
 --> src/main.rs:1:8
  |
1 | struct 🦀;
  |        ^^ help: try using their name instead: `ferris`

or a const

error: Ferris cannot be used as an identifier
 --> src/main.rs:1:7
  |
1 | const 🦀: Crab = Crab::with_name("Ferris");
  |       ^^ help: try using their name instead: `ferris`

[boehs]

I think we need more bullshit like this. Next step would be including the whole gemoji crate into compiler codebase to be able to name any emoji, not just Ferris only.

I think this is sarcastic but it would sure be fun!

[pro465]

what the....

[arthurfiorette]

@m-ou-se Any chance we get 🦀 as the only allowed emoji identifier?
This is seriously preventing me from continuing to use rust in my projects.

[estebank]

@arthurfiorette that would require t-lang sign-off. It would be too whimsical to do so, but I'm not against whimsy.

[arthurfiorette]

I'm not familiar with the rust "workflow" for it... How can I start the process to get a t-lang sign-off? 😁

[m-ou-se]

Adding 🦀 as an accepted identifier in Rust means removing this easter-egg, though. ^^