Struct Command 

pub struct Command<'a> {

    pub name: &'a str,
    pub aliases: &'a [&'a str],
    pub flags: &'a [&'a Flag<'a>],
    pub args: &'a [&'a Arg<'a>],
    pub subcommands: &'a [&'a Command<'a>],
    pub default_subcommand: Option<&'a Command<'a>>,
    pub external_subcommand: bool,
    pub arg_required_else_help: bool,
    pub subcommand_negates_reqs: bool,
    pub args_conflicts_with_subcommands: bool,
    pub subcommand_precedence_over_arg: bool,
    pub allow_missing_positional: bool,
    pub dont_delimit_trailing_values: bool,
    pub unknown_flags: Option<UnknownFlags>,
    pub version: bool,
    pub disable_help_flag: bool,
    pub disable_help_subcommand: bool,
    pub disable_version_flag: bool,
    pub key: u64,
}

A command: its flags, its positional arguments, and its subcommands.

Every field is a borrowed slice so that a derive can emit the whole tree as static data. Use ..Command::EMPTY to fill in the parts you do not need.

Fields

name: &'a str

The canonical name, used to select this command.

aliases: &'a [&'a str]

Alternative names that also select it.

flags: &'a [&'a Flag<'a>]

args: &'a [&'a Arg<'a>]

Positional arguments, in the order they are filled.

subcommands: &'a [&'a Command<'a>]

default_subcommand: Option<&'a Command<'a>>

Where a word goes when it names no subcommand of this one.

The spec’s default_subcommand. mise build means mise run build: the word names no command, so the parser descends into run and lets run have it — even where this command declares an argument of its own, which is what makes the property worth having rather than a synonym for a positional.

Applied at most once per parse, so a CLI cannot loop through it, and only where a subcommand could still be selected.

Resolve it with find_subcommand, which turns a name that no subcommand answers to into a compile error.

external_subcommand: bool

Whether an unmatched word is forwarded as an external command plus the rest of argv.

clap’s allow_external_subcommands. Known subcommands still win; a default_subcommand still catches first. Once the unmatched word is taken, remaining tokens — including --help — are not parsed as this command’s flags.

arg_required_else_help: bool

Show this command’s help when no argv token follows its name.

This is clap’s arg_required_else_help. It deliberately observes argv rather than bound values: an environment variable or default may fill a field, but neither means the user supplied an argument to this invocation.

subcommand_negates_reqs: bool

Selecting a subcommand suppresses this command’s required arguments.

args_conflicts_with_subcommands: bool

Once this command binds a flag or positional, selecting one of its subcommands is an error.

subcommand_precedence_over_arg: bool

Let a known subcommand interrupt a variadic argument that would otherwise consume it.

allow_missing_positional: bool

Let a later required positional take a word while an earlier optional positional remains empty.

dont_delimit_trailing_values: bool

Disable delimiter splitting for positional values after -- or on an automatic trailing argument. Inherited by subcommands.

unknown_flags: Option<UnknownFlags>

What an unrecognized flag-like token means here, or None to keep whatever the enclosing command said. See UnknownFlags.

Inherited rather than resolved per command, which is what usage-lib does — its effective_unknown_flags walks outward from the command that ran and falls back to the spec’s. Resolving it in the tables instead was possible only for a builder that can see the whole tree: a derive expands one struct at a time and cannot see its parent, so #[usage(unknown_flags = "error")] on the root reached the root alone and a subcommand had no way to say it at all.

The parser carries the effective value down as it descends, so a command that states nothing costs nothing.

version: bool

Whether this command answers to --version and -V.

Set on the root, and only when the CLI declares a version: clap adds the flag exactly then, and a --version that answers with nothing is worse than one that is not there. A field rather than a rule about depth, so a CLI that wants it on a subcommand — clap’s propagate_version — has somewhere to say so.

disable_help_flag: bool

Do not synthesize --help and -h for this command.

disable_help_subcommand: bool

Do not synthesize the help subcommand route for this command.

disable_version_flag: bool

Do not synthesize --version and -V for this command.

key: u64

Caller-assigned identifier, echoed back in Event::Command.

Wide enough for a derive to make these unique without coordination: two macro expansions cannot see each other, so the generated keys carry a hash of the type they came from in the high half and a per-type index in the low half. A parse dispatches on this, so a collision would bind the wrong field — Spec::to_kdl checks the tree for duplicates in debug builds.

Implementations

impl Command<'_>

pub const EMPTY: Command<'static>

A command with nothing declared, for use with struct update syntax.

Trait Implementations

impl<'a> Clone for Command<'a>

fn clone(&self) -> Command<'a>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Copy for Command<'a>

impl<'a> Debug for Command<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Eq for Command<'a>

impl<'a> PartialEq for Command<'a>

fn eq(&self, other: &Command<'a>) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<'a> StructuralPartialEq for Command<'a>