In text communication you need to balance
- Scannability, putting the most important information upfront
- Brevity so people don't get lost in the message
- Softness to help ease people through a frustrating experience
I feel we weren't doing great on the first two points, so tried to
iterate on the messages to improve them. I hope we aren't suffering too
much on the third point as a side effect.
From
https://rustc-dev-guide.rust-lang.org/diagnostics.html#suggestion-style-guide
> Suggestions should not be a question. In particular, language like
> "did you mean" should be avoided. Sometimes, it's unclear why a
> particular suggestion is being made. In these cases, it's better to be
> upfront about what the suggestion is.
>
> The message may contain further instruction such as "to do xyz, use"
> or "to do xyz, use abc".
Inspired by #2766
This is a cheap pass at creating this to allow cutting out the cost of
rich error information / programmatic error information.
This cuts about 20 KiB off of the binary.
There is more we could cut out, like collecting of used arguments for
the usage, but I want to keep the conditionals simple.
In looking at other help output, I noticed that they use two spaces, in
place of clap's 4, and it doesn't suffer from legibility. If it
doesn't make the output worse, let's go ahead and make it as dense so we
fit more content on the screen.
This is a part of #4132
I see them fulfilling two roles
- A form of bolding
- As a callback to their placeholder in usage
However, it is a bit of an unpolished look and no other CLI seems to do
it. This looks a bit more proefessional. We have colored help for
formatting and I think the sections relation to usage will be clear
enough.
This mostly exist for
- Knowing of the value came from the command-line but we now have
`ArgMatches::source`
- Counting the number of flags but we now have `ArgAction::Count`
This is a step towards #3309. We want to make longs and long aliases
more consistent in how they handle leading dashes. There is more
flexibility offered in not stripping and it matches the v3 short
behavior of only taking the non-dash form. This starts the process by
disallowing it completely so people will catch problems with it and
remove their existing leading dashes. In a subsequent breaking release
we can remove the debug assert and allow triple-leading dashes.
This is prep for moving the derive tests. Besides organizing the test
folder for each API, this should reduce link time at the cost of
re-compiling more when a test changes.
