We were accidentally showing long help just because a hidden argument had a description for a possible value. This is most likely to be hit with the derive API as the value descriptions are automatically applied from documentation.
Adding "found" might seem minor but I feel it has a slight softening on the message. It also maintains scanability as it is at the end and short.
As this is a one-off message change and not a styling issue to be consistent with, I think this is safe to put in a patch release.
This let's you get an arguments values, grouped by the occurrence of the
argument.
Note: this does not stablize derive support. That requires a blocking
change and can be enabled via `unstable-v5` flag. See #4626 for an
exploration of how we can make this easier in the future.
Fixes#2924
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.
This is an intermediate solution for #4408. As there were no agreeed
upon goals, I went with what I felt read well and that I saw commonly
used on non-clap commands.
- "information" isn't really a necessary word.
- I originally favored `Print this help` but realied that doesn't read
correctly in completions.
- Besides being shorter, the reason for the flipped short/long hint is
it gives people the context they need for scanning, emphasizing
"summary" and "more".
Fixes#4409
Similar to
- Listing all required arguments when one is missing
- Listing all possible values when no value is provided
This came up when discussing #3572
Making this plural can go either way as
- Clarify it is plural
- This is all really to simulate actually doing subcommands and you only
do one at a time
For now, I lean towards clarifying it is plural
I also tweaked the message to be more consistent with how `--help` and
`-h` describe themselves.
Fixes#4342
In clap v4, we changed the padding from 4 to 2 but we didn't update our
calculation for when to switch to next-line-help as it was a magic
number (we tried to catch all of these).
When updating the tests, we also missed that a test was being wrapped
too narrowly
This was found while discussing #3300
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 will fix `clap_derive`s behavior for optional-flattened groups as
it will properly detect when the group is present (#3566).
While I consider this a bug and not part of compatibility guarentees, I
still want to keep in mind user impact which could still prevent this.
Defaults will make the group always-present which has little value and
if anything is relying on this, it is probably an application bug.
When overriding other fields, help or version flag, globals, etc, a user
might not care about the value, so let's ignore the lookup.
Been talking about this for a while but Issue #4367 moved this forward
because there wasn't a good way to handle this without changing
behavior.
If users don't want `wrap_help` feature, they can put newlines in where
needed. Seems odd to support wrapping when the wrap size is fixed. For
those hard coding the lines, this will save them a decent amount of
size.
The writer is less convenient and isn't offering any performance
benefits of avoidign the extra allocations, so let's render instead.
This supersedes #3874Fixes#3873
`clap::Error::raw` was producing ambiguity errors with a default generic
parameter on `clap::error::Error` (which `clap::Error` is a re-export
of).
I tried making `clap::Error` a type alias with a default generic
parameter but that ran into an ambiguity error with `map_err`.
So I'm going ahead and hard coding `clap::Error`. We don't expect
people to change this all that often.
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.
Originally, clap carried a lifetime parameter. When moving away from
that, we took the approach that dynamically generated strings are always
supported and `&'static str` was just an optimization.
The problem is the code size increase from this is dramatic. So we're
taking the opposite approach and making dynamic formatting opt-in under
the `string` feature flag. When deciding on an implementation, I
favored the faster one rather than the one with smaller code size since
small code size can be gotten through other means.
Before: 567.2 KiB, 15.975 µs
After: 541.1 KiB, 9.7855 µs
With `string`: 576.6 KiB, 13.016 µs
This makes us accept `str` and not do any allocations at the cost of
panicing if unsupported which I think fits our overall story in trying
to catch development-time errors.
Originally, I saw the ideal as the parent command being isolated from
`#[clap(flatte)]` especially after all of the doc comment
leakage issues. We scaled that back to just `next_help_heading` because
of the issues with settling on a policy and maintenance to cover
everything. When doing `next_display_order`, we decided it would mess
things up too much to isolate it.
With #1807, we instead have been moving towards setting
`#[command(next_help_heading)]` anywhere, we just need to finish working
out how it should work.
Just having `--help` or `--version` can make us get invalid args instead
of invalid subcommands. It doesn't make sense to do this unless
positionals are used. Even then it might not make sense but this is at
least a step in the right direction.
Unsure how I feel about this being backported to clap 3. It most likely
would be fine?
This was noticed while looking into #4218
Since the `name` is changed to be the package name, we can't use it as
(1) its not as predictable and (2) it can lead to conflicts if a
`Parser` is flattened into a `Parser`
This was ported over from the usage parser which modeled after docopt.
We just never got around to implementing the rest of the syntax.
However, when considering this as a standalone feature, an
`arg!(--flag <value>)`, outside of other context, should be optional.
This is how the help would display it.
Fixes#4206
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
If short help is too long for the terminal, clap will automatically
switch to next line help. As part of next line help for longs, we add a
blank line between args. This helps make the args clearer when dealing
with multiple paragraphs. However, its not as much needed for short and
subcommands (always short), so now short matches subcommands.
This was inspired by #3300 and a part of #4132
This makes it match up with `Command::allow_hyphen_values` which was the
guiding factor for what the behavior should be.
This supersedes #4039Fixes#3880Fixes#1538
This has been a bit out of place being on the command. Now its clearer
what the user intends to be the trailing var arg and it is more likely
to be discovered.
The builder function was deprecated in v3 and removed in v4 but the
derive masked that, so we're still adapting things but now with a path
towards removal.
In reviewing CLIs for #4132, I found some were providing helps on `-h`
vs `--help` and figured that could be built directly into clap. I had
considered not making this hint automatic but I figured the overhead of
checking if long exists wouldn't be too bad. The code exists (no binary
size increase) and just a simple iteration is probably not too slow
compared to everything else.
Fixes#1015
This ensures we don't end up with accidental leading or trailing
newlines due to help template variables not being used when a section is
empty.
This is prep for removing name/version from the default template and is
part of #4132
In switching to title case for help headings (#4123), it caused me to
look at "subcommand" in a fresh light. I can't quite put my finger on
it but "Subcommand" looks a bit sloppy. I also have recently been
surveying other CLIs and they just use "command" as well.
All of them are commands anyways, just some are children of others
(subcommands) while others are not (root or top-level commands, or just
command). Context is good enough for clarifying subcommands from root
commands.
This is part of #4132
The setting was added to resolve#769. The reason it was optional is out
of concern for applications with a lot of positional arguments. I think
those cases are rare enough that we should just push people to override
the usage. Positional arguments are generally important enough, even if
optional, to show.
As a side effect, this fixed some bugs with
`dont_collapse_args_in_usage` where it would repeat an argument in a
smart usage.
As a side effect, smart usage now shows `--` when it should
This prevents global args from showing in help completions,
since help completions should only suggest subcommands.
Adds tests to ensure the args still show in the generated
help messages of subcommands.
In surveying various tools and CLI parsers, I noticed they list the
subcommands first. This puts an emphasis on them which makes sense
because that is most likely what an end user is supposed to pass in
next.
Listing them last aligns with the usage order but it probably doesn't
outweigh the value of getting a user moving forward.
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.
For now, there isn't much a custom implementation can do.
Going from `Rich` to `Null` drops about 6 KiB from the binary
This is a part of #1365 and #1384
While `TypedValueParser` will generally make it easier to reuse value
parsers, this was particularly written for flags. Besides having a
concrete API to document, an advantage over `fn(&str) -> Result<bool, E>`
value parsers is you get all of the benefits of the existing value
parsers for environment variable parsing.
