Struct Parameter 

pub struct Parameter<'a, T>(/* private fields */);

An argument/option for the command parser. Used with CommandLineParser::add and SubCommand::add.

Implementations

impl<'a, T> Parameter<'a, T>

pub fn option( field: impl GenericCapturable<'a, T> + CliOption + 'a, name: impl Into<String>, short: Option<char>, ) -> Self

Create an option parameter.

Example

use blarg::{Parameter, Switch};

let mut verbose: bool = false;
Parameter::option(Switch::new(&mut verbose, true), "verbose", Some('v'));

pub fn argument( field: impl GenericCapturable<'a, T> + CliArgument + 'a, name: impl Into<String>, ) -> Self

Create an argument parameter.

Example

use blarg::{Parameter, Scalar};

let mut verbose: bool = false;
Parameter::argument(Scalar::new(&mut verbose), "verbose");

pub fn help(self, description: impl Into<String>) -> Self

Document the help message for this parameter. If repeated, only the final message will apply to the parameter.

A help message describes the parameter in full sentence/paragraph format. We recommend allowing blarg to format this field (ex: it is not recommended to use line breaks '\n').

See also:

• Parameter::meta
• Parameter::choice

Example

use blarg::{Parameter, Scalar};

let mut verbose: bool = false;
Parameter::argument(Scalar::new(&mut verbose), "verbose")
    .help("--this will get discarded--")
    .help("Make the program output verbose.  Description may include multiple sentences.");

pub fn meta(self, descriptions: Vec<impl Into<String>>) -> Self

Document the meta message(s) for this parameter. If repeated, only the final message will apply to the parameter.

Meta message(s) describe short format extra details about the parameter. We recommend non-sentence information for this field.

See also:

• Parameter::help
• Parameter::choice

Example

use blarg::{Parameter, Scalar};

let mut verbose: bool = false;
Parameter::argument(Scalar::new(&mut verbose), "verbose")
    .meta(vec!["--this will be discarded--"])
    .meta(vec!["final extra", "details"]);

Trait Implementations

impl<'a, T: Display> Choices<T> for Parameter<'a, T>

fn choice(self, variant: T, description: impl Into<String>) -> Self

Document a choice’s help message for this parameter. If repeated for the same variant of T, only the final message will apply to the parameter. Repeat using different variants to document multiple choices. Needn’t be exhaustive.

A choice help message describes the variant in full sentence/paragraph format. We recommend allowing blarg to format this field (ex: it is not recommended to use line breaks '\n').

Notice, the documented or un-documented choices do not affect the actual command parser semantics. To actually limit the command parser semantics, be sure to use an enum.

See also:

• Parameter::help
• Parameter::meta

Example

use blarg::{prelude::*, Parameter, Scalar};
use std::str::FromStr;

let mut door: u32 = 0;
Parameter::argument(Scalar::new(&mut door), "door")
    .choice(1, "--this will get discarded--")
    .choice(1, "Enter door #1.")
    .choice(2, "Enter door #2.  Description may include multiple sentences.");