Struct Argument 

pub struct Argument {
    pub name: String,
    pub description: String,
    pub required: bool,
    pub default: Option<String>,
    pub variadic: bool,
}

A positional argument accepted by a command.

Arguments are bound in declaration order when the parser consumes tokens after the command (and any subcommand) has been identified. Optional arguments may carry a default value that is substituted when the argument is absent.

Use Argument::builder to construct instances.

Examples

let arg = Argument::builder("target")
    .description("Deployment target environment")
    .required()
    .build()
    .unwrap();

assert_eq!(arg.name, "target");
assert!(arg.required);
assert!(arg.default.is_none());

Fields

name: String

The canonical name of this argument, used as the key in crate::ParsedCommand::args.

description: String

Human-readable description shown in help output.

required: bool

Whether the parser returns an error when this argument is absent.

default: Option<String>

Value substituted when the argument is not provided (optional arguments only).

variadic: bool

Whether this argument consumes all remaining tokens (must be the last argument).

Implementations

impl Argument

pub fn builder(name: impl Into<String>) -> ArgumentBuilder

Create a new ArgumentBuilder with the given name.

Arguments

• name — The argument name. Must be non-empty after trimming (enforced by ArgumentBuilder::build).

Examples

let arg = Argument::builder("file").build().unwrap();
assert_eq!(arg.name, "file");

Trait Implementations

impl Clone for Argument

fn clone(&self) -> Argument

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Argument

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Argument

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for Argument

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Argument

fn cmp(&self, other: &Argument) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Argument

fn eq(&self, other: &Argument) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Argument

fn partial_cmp(&self, other: &Argument) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for Argument

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for Argument

impl StructuralPartialEq for Argument