Upper-case name where no enum is expected

Built from the repository at commit a8614dc.

A name that starts with an upper-case letter in a pattern names a variant, so it can stand only where the value is an enum. Where the value is an integer, a bool, a char or a string, a pattern name is a binding, and a binding starts with a lower-case letter.

Why

An upper-case name reads as a variant, perhaps misspelled, not as a new name for the value, so the compiler does not quietly bind it. The fix lower-cases the first letter. It is unsafe, since the new name may clash with another.

Broken

fn main() {
    let n = match 3 {
        Count => Count + 1
    }
    print(n)
}

What sisu says

error[E0125]: `Count` is not a variant here
 --> E0125.sisu:3:9
  |
3 |         Count => Count + 1
  |         ^^^^^
  |
  = help: a binding starts with a lower-case letter
help: write `count`
  |
3 -         Count => Count + 1
3 +         count => Count + 1
  |

sisu: 1 error
sisu: for more on a code, run `sisu explain <code>`: E0125

Fixed

fn main() {
    let n = match 3 {
        count => count + 1
    }
    print(n)
}