Format spec width or precision above its limit

Built from the repository at commit a8614dc.

A width in a format spec is at most 1000, and a precision at most 30: {x:1000.30} is the largest spec. The error points at the spec, from its :, and names the limit it breaks.

Why

The limits bound the room one formatted part takes in the result, so a program cannot ask for a megabyte of padding by mistake. A width above 1000 or a precision above 30 is almost always a typo. There is no fix, since the value you meant is not known.

Broken

fn main() {
    let x = 2.5
    print("{x:.31}")
}

What sisu says

error[E0110]: a precision is at most 30
 --> E0110.sisu:3:14
  |
3 |     print("{x:.31}")
  |              ^^^^

sisu: 1 error
sisu: for more on a code, run `sisu explain <code>`: E0110

Fixed

fn main() {
    let x = 2.5
    print("{x:.3}")
}

Related

• E0108: a format spec that the grammar does not hold.