[Language construct idea] The for loop with prepare step

[Paul Backus]

On Monday, 12 February 2024 at 15:58:50 UTC, Quirin Schroll wrote:
> Extend `for` to `for (init; prepare; condition; increment) 
> body`.
>
> The step `prepare` is executed before each check.

I've never heard of anything like this in any other programming 
language, so I'm skeptical by default.

Do you have any examples of code that this feature would improve?