# XO0906: a match that `??` writes shorter

Reported by `xo vet`, not `xo check`. `match opt { Some(v) => v  None => return r }` (or `continue`, `break`) is the Option form of `opt ?? return r`: the right side of `??` may leave the function or the loop. On a Result, `match r { Ok(v) => v  Err(e) => return w }` is `r ?? e => return w` (`Err(_)` gives `_ =>`). The fix rewrites it.

## Example

```xo
fn first(xs: List[Int]) -> Int? {
  let v = match xs.first() {
    Some(x) => x
    None => return None
  }
  Some(v)
}
```

## Fix

```xo
fn first(xs: List[Int]) -> Int? {
  let v = xs.first() ?? return None
  Some(v)
}
```

Run `xo explain XO0906` for this text in a terminal, or see
[section 10.6 of the specification](../../spec/core/#106-diagnostic-codes).