Sisu
E0013

var instead of let mut

Error

Built from the repository at commit a8614dc.

Sisu has no var. A variable that can change is declared with let mut, and a field that can change is marked mut.

Why

mut marks everything that can change (ADR 0011), so there is one keyword for it, in bindings and in fields.

Broken

fn main() {
    var count = 0
    count += 1
    print(count)
}

What sisu says

error[E0013]: there is no `var` in Sisu
 --> E0013.sisu:2:5
  |
2 |     var count = 0
  |     ^^^
  |
  = help: Sisu declares a variable with `let mut`

sisu: 1 error
sisu: for more on a code, run `sisu explain <code>`: E0013

Fixed

fn main() {
    let mut count = 0
    count += 1
    print(count)
}