Retain/keep help arguments sorting?

[vn971]

Hi, thanks for the awesome project!
Is it possible to keep arguments sorting the same as written in the underlying struct? I think there are cases when you want to write arguments in a certain order, and I think it'd be nice to retain this order.

[vn971]

(I tried to think of a MergeRequest, but I can't find any obvious places like a use of HashMap / HashSet. Not sure what's the source of reordering.)

[CreepySkeleton]

Define "argument-sorting"? I don't understand the question; some examples might help.

[vn971]

I mean in the --help message. For example, given this structopt definition: https://gitlab.memri.io/memri/pod/-/blob/1eb5f671c5270a3cf2a649339d12cd522cf32dca/src/command_line_interface.rs

I get an output like this: https://gitlab.memri.io/memri/pod/snippets/1

As you see, even though "port" is defined first in the source code ( #[structopt(short, long, default_value = "3030")] port: i16, ), it will be in fact listed somewhere in the bottom ( -p, --port <port> Port to listen to [default: 3030] ).

Would it be possible or a better idea to preserve ordering?

[vn971]

( The problem persists if AppSettings::UnifiedHelpMessage is commented out as well )

[TeXitoi]

AppSettings::DeriveDisplayOrder

[vn971]

@TeXitoi oh nice, thanks a lot! It works! Is there a reason to not "enable" it by default?

[TeXitoi]

That's clap default. But I personally prefer this default, as it makes search in the help message easier.

[CreepySkeleton]

Is there a reason to not "enable" it by default?

So many men, so many minds. Some prefer alphabetical sorting, some like "as declared" sorting. It's just happened that the former is default, the latter is opt-in, and I also think alphabetical is more common.

[vn971]

@CreepySkeleton that is not alphabetical sort in the first example sort though, is it? https://gitlab.memri.io/memri/pod/snippets/1
I don't recognize the type of sorting at all. When I changed some options around, some options that weren't change actually got swapped, the whole "picture" is moving randomly.

[CreepySkeleton]

That's... weird. I swear I saw the "alphabetical order" in clap docs, lemme check... nope, I'm not delusional

Displays the arguments and SubCommands in the help message in the order that they were declared in, and not alphabetically which is the default.

Well, I guess you're going to have to live with it until clap 3.0 is out, sorry.

[vn971]

Is it a bug in clap then? I'm a bit lost. It would seem that the latest version of structopt already uses clap 2.33.0, but options are not listed alphabetically in --help.. Am I missing something here?

[CreepySkeleton]

Yes, this is a bug in clap 2.33. Unfortunately, it's unlikely to ever be fixed because all time we have we put into 3.0; clap 2.x is essentially frozen. You don't seem to be affected by the bug because you use DeriveDisplayOrder, and if you were, you could assign the order manually via display_order = 1, 2, 3... as a workaround.

I'll make sure this is fixed in 3.0.

[vn971]

Thanks, understood, all clear now!