Adding a hint on iterator type errors

[petar-dambovaliev]

rust version: rustc 1.66.0 (69f9c33d7 2022-12-12)

error[E0277]: `{float}` is not an iterator
  --> tests/core.rs:44:14
   |
44 |     for i in 0.200 {
   |              ^^^^^ `{float}` is not an iterator

Do you think it would be useful to add a hint here?
Something in the lines of Did you mean for i 0..200 {

[clubby789]

@rustbot claim

[petar-dambovaliev]

@clubby789 i was hoping this to be my first PR to the compiler, if accepted as necessary. :D
I need some guidance as to where this code might be though...

[tdelabro]

@rustbot claim

[tdelabro]

hups sorry

[tdelabro]

I was testing the bot feature

[clubby789]

@petar-dambovaliev

I need some guidance as to where this code might be though...

The 'is not an iterator' message comes from the rustc_on_unimplemented attribute. One solution would be to add a new case to that attribute which detects literals of the form <lhs>.<rhs> (where both sides are numeric) and suggests the iterator syntax.

[petar-dambovaliev]

rustc_on_unimplemented

thanks!

[petar-dambovaliev]

@clubby789 is this in the right direction? #106740