Struct Arg 

pub struct Arg<'a> {
    pub key: u64,
    pub required: bool,
    pub var: bool,
    pub var_max: Option<u32>,
    pub delimiter: Option<u8>,
    pub allow_negative_numbers: bool,
    pub value_terminator: Option<&'a [u8]>,
    pub double_dash: DoubleDash,
    pub name: &'a str,
}

A positional argument.

Fields

key: u64

Caller-assigned identifier, echoed back in Event::Arg. See Command::key on why it is this wide.

required: bool

Whether post-binding requires this positional to have a value. Kept in the hot table because allow_missing_positional must reserve words for later required args.

var: bool

Whether this argument keeps taking values once it has one.

var_max: Option<u32>

How many words a variadic may take before the next argument gets the rest.

A bound belongs here, in the table binding reads, rather than with the metadata: it decides where a word lands, not whether what landed is acceptable. clap’s num_args works the same way, and every spec in the wild is generated from a clap command. u32 rather than usize because a CLI that bounds a variadic above four billion has other problems, and this table is read on the hot path.

delimiter: Option<u8>

The byte that makes one word several values, if the argument declares one.

See Flag::delimiter: a bound counts values, and only this says how many values a word carries.

allow_negative_numbers: bool

Whether a negative-number token is accepted as this positional even in strict flag mode.

value_terminator: Option<&'a [u8]>

A token that ends this variadic positional without becoming a value.

double_dash: DoubleDash

This argument’s relationship to the -- separator.

name: &'a str

Unused by binding, kept so a table entry can carry its own name for diagnostics.

Implementations

impl Arg<'_>

pub const REQUIRED: Arg<'static>

A single-value argument, for use with struct update syntax.

pub const VAR: Arg<'static>

A variadic argument, for use with struct update syntax.

Trait Implementations

impl<'a> Clone for Arg<'a>

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Copy for Arg<'a>

impl<'a> Debug for Arg<'a>

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

Formats the value using the given formatter.

impl<'a> Eq for Arg<'a>

impl<'a> PartialEq for Arg<'a>

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

Equality operator ==.

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

Inequality operator !=.

impl<'a> StructuralPartialEq for Arg<'a>