Update to clap 4

[tjquillan]

This updates delta to clap version 4.0.29. With all the migrations that come along with it. I am leaving this as a draft for now as I still need to make the correct updates to the code. I will list the changes and important parts of 4.0.0 here as I go. I will try to do each change as a single commit so they can be dropped or changed as needed.

Changes:

• Add clap features help,usage,error-context
  • If default-features = false, run cargo add clap -F help,usage,error-context
• Add clap feature wrap_help
  • Run cargo add clap -F wrap_help unless you want to hard code line wraps
• Remove DeriveDisplayOrder as it is now the default
  • Make DeriveDisplayOrder the default and removed the setting.
• Update ValueSource using statement
  • clap::{Indices, OsValues, ValueSource, Values} to clap::parser::{Indices, OsValues, ValueSource, Values}
• Update #[clap(...)] to #[command(...)] where appropriate
  • Attribute #[clap(...)] has been deprecated in favor of #[command(...)]
• Update #[clap(...)] to #[arg(...)] where appropriate
  • Attribute #[clap(...)] has been deprecated in favor of #[arg(...)]
• Update #[structopt(...)] to #[arg(...)] where appropriate
  • Attribute #[structopt(...)] has been deprecated in favor of #[arg(...)]
• Remove value_parser because it is now default
  • Changed the default for arguments from parse to value_parser

[dandavison]

Great, thanks for this work @tjquillan. I'll look forward to the final version.

[tjquillan]

@dandavison If possible I could use your input on an issue I am encountering. It seems as of 4.0.0 Arg::get_id returns a &Id instead of a &str. Taking the simple approach of replacing mentions in the function of name with name.as_str() as shown below gives the following error:

pub fn get_argument_and_option_names<'a>() -> HashMap<&'a str, &'a str> {
        itertools::chain(Self::command().get_opts(), Self::command().get_arguments())
            .filter_map(|arg| match (arg.get_id(), arg.get_long()) {
                (name, Some(long)) => {
                    if IGNORED_OPTION_NAMES.contains(name.as_str()) {
                        None
                    } else {
                        Some((name.as_str(), long))
                    }
                }
                _ => None,
            })
            .collect()
    }

error[E0515]: cannot return value referencing temporary value
    --> src/cli.rs:1176:9
     |
1176 |           itertools::chain(Self::command().get_opts(), Self::command().get_arguments())
     |           ^                                            --------------- temporary value created here
     |  _________|
     | |
1177 | |             .filter_map(|arg| match (arg.get_id(), arg.get_long()) {
1178 | |                 (name, Some(long)) => {
1179 | |                     if IGNORED_OPTION_NAMES.contains(name.as_str()) {
...    |
1186 | |             })
1187 | |             .collect()
     | |______________________^ returns a value referencing data owned by the current function

I am very much new to rust so I don't exactly know what a solution to this would look like (it is very possible the answer is obvious to an experienced rust programmer). An alternative I see would be to change the HashMap to HashMap<&'a Id, &'a str>.

[tjquillan]

From some looking I wonder if clap-rs/clap#4103 and clap-rs/clap#4223 might be related.

Relevant changelog:

• Removed lifetimes from Command, Arg, ArgGroup, and PossibleValue, assuming 'static. string feature flag will enable support for Strings

[dandavison]

Thanks very much for this work @tjquillan. Your commits were included in @nickelc's work #1322 which has merged.