Character that Sisu does not use

Built from the repository at commit a8614dc.

Source text uses only the characters of Sisu's tokens. Any other character outside a comment is an error. A lone & or | is most likely a logical && or || written with one character.

Why

The compiler cannot tell what an unknown character was meant to be. For & and | the mistake is common enough that the report offers && or || as an unsafe fix, which you check before you apply it.

Broken

fn main() {
    let ok = true & false
    print(ok)
}

What sisu says

error[E0010]: unexpected character `&`
 --> E0010.sisu:2:19
  |
2 |     let ok = true & false
  |                   ^
  |
help: if you meant logical and, use `&&`
  |
2 |     let ok = true && false
  |                    +

sisu: 1 error
sisu: for more on a code, run `sisu explain <code>`: E0010

Fixed

fn main() {
    let ok = true && false
    print(ok)
}