vendor/clap/examples/derive_ref/hand_subcommand.rs

   1 use clap::error::{Error, ErrorKind};
   2 use clap::{ArgMatches, Args as _, Command, FromArgMatches, Parser, Subcommand};
   3
   4 #[derive(Parser, Debug)]
   5 struct AddArgs {
   6     #[clap(value_parser)]
   7     name: Vec<String>,
   8 }
   9 #[derive(Parser, Debug)]
  10 struct RemoveArgs {
  11     #[clap(short, long, action)]
  12     force: bool,
  13     #[clap(value_parser)]
  14     name: Vec<String>,
  15 }
  16
  17 #[derive(Debug)]
  18 enum CliSub {
  19     Add(AddArgs),
  20     Remove(RemoveArgs),
  21 }
  22
  23 impl FromArgMatches for CliSub {
  24     fn from_arg_matches(matches: &ArgMatches) -> Result<Self, Error> {
  25         match matches.subcommand() {
  26             Some(("add", args)) => Ok(Self::Add(AddArgs::from_arg_matches(args)?)),
  27             Some(("remove", args)) => Ok(Self::Remove(RemoveArgs::from_arg_matches(args)?)),
  28             Some((_, _)) => Err(Error::raw(
  29                 ErrorKind::UnrecognizedSubcommand,
  30                 "Valid subcommands are `add` and `remove`",
  31             )),
  32             None => Err(Error::raw(
  33                 ErrorKind::MissingSubcommand,
  34                 "Valid subcommands are `add` and `remove`",
  35             )),
  36         }
  37     }
  38     fn update_from_arg_matches(&mut self, matches: &ArgMatches) -> Result<(), Error> {
  39         match matches.subcommand() {
  40             Some(("add", args)) => *self = Self::Add(AddArgs::from_arg_matches(args)?),
  41             Some(("remove", args)) => *self = Self::Remove(RemoveArgs::from_arg_matches(args)?),
  42             Some((_, _)) => {
  43                 return Err(Error::raw(
  44                     ErrorKind::UnrecognizedSubcommand,
  45                     "Valid subcommands are `add` and `remove`",
  46                 ))
  47             }
  48             None => (),
  49         };
  50         Ok(())
  51     }
  52 }
  53
  54 impl Subcommand for CliSub {
  55     fn augment_subcommands(cmd: Command<'_>) -> Command<'_> {
  56         cmd.subcommand(AddArgs::augment_args(Command::new("add")))
  57             .subcommand(RemoveArgs::augment_args(Command::new("remove")))
  58             .subcommand_required(true)
  59     }
  60     fn augment_subcommands_for_update(cmd: Command<'_>) -> Command<'_> {
  61         cmd.subcommand(AddArgs::augment_args(Command::new("add")))
  62             .subcommand(RemoveArgs::augment_args(Command::new("remove")))
  63             .subcommand_required(true)
  64     }
  65     fn has_subcommand(name: &str) -> bool {
  66         matches!(name, "add" | "remove")
  67     }
  68 }
  69
  70 #[derive(Parser, Debug)]
  71 struct Cli {
  72     #[clap(short, long, action)]
  73     top_level: bool,
  74     #[clap(subcommand)]
  75     subcommand: CliSub,
  76 }
  77
  78 fn main() {
  79     let args = Cli::parse();
  80     println!("{:#?}", args);
  81 }