I’ve been writing a small program (that I’m hoping to showcase soon!) that needs to walk a directory tree to do its job.

The basic code I want to write is as follows:

while (walker.next()) |ok| {
    const entry = ok orelse break; // walker is finished
    // do stuff with entry...
} else |err| {
    switch (err) {
        // handle errors, mostly by just printing them
    }
    continue;
}

But it doesn’t compile, because the continue in the final line is not considered to be in a loop!

I’ve tried handling errors inside the condition, but that lead me to multiple layers of while loops to avoid the terminate-on-error behavior and really seemed excessively large and rather unreadable for what it was trying to achieve.

A second-best sort of solution I thought up was to somehow invert the optional and error (turning Error!?Entry into ?Error!Entry) writing the loop like so:

while (invert(walker.next())) |err| {
    const entry = err catch |e| switch (e) {
        // handle errors, mostly by just printing them
    }
    // do stuff with entry...
}

But although the invert() function does seem like it will work, at this point I started getting the feeling that I’m on the wrong track altogether here and am missing a much simpler solution. Is there a better way, or is this the way to go about it?

vulpesx July 11, 2026, 12:57pm 2 

while (true) {
    // not sure if () are needed...
    const entry = (walker.next() catch |e| switch (e) {
        //...
    }) orelse break;
    // or perhaps split into 2 consts
}

Simple as that, huh?
It works great, thanks a lot!