This commit primarily changes to a lazy handling of POSIX overrides by
relying on github.com/bluss/ordermap instead of the old HashMap impl.
The ordermap allows us to keep track of which arguments arrived first,
and therefore determine which ones should be removed when an override
conflict is found.
This has the added benefit of we no longer have to do the bookkeeping to
keep track and override args as they come in, we can do it once at the
end.
Finally, ordermap allows fast Vec like iteration of the keys, which we
end up doing several times. Benching is still TBD once the v3 prep is
done, but this change should have a meaningful impact.
Contains a *MINOR* breaking change. App::write_help now requires `&mut self` instead of `&self`.
This fixes a major bug where the help message is entirely incorrect.
More can be found at https://github.com/kbknapp/clap-rs/issues/808
I've decided to make this change because it was preventing further progress.
Anyone's code who breaks the fix is trivial:
```rust
// OLD BROKEN
let app = App::new("broken");
let mut out = io::stdout();
app.write_help(&mut out).expect("failed to write to stdout");
// NEW FIX
let mut app = App::new("broken"); // <-- let mut
let mut out = io::stdout();
app.write_help(&mut out).expect("failed to write to stdout");
```
Closes#808
Optional positionals mixed with subcommands will still break this, since
I can't see how to tell which element of $line is the command than.
Mixing optional positionals with subcommands is a bit weird and awkward
though...
This changes the way we complete positionals to complete them using
_arguments, as should be done, instead of completing their uppercase name
as a string.
Currently I made it offer _files completion for all positional arguments.
This can be improved to complete actual possible values of the arguments
and only complete files if the argument truly takes them. But this will
require further changes in clap to actually have the required
functionality to get this information.
