Struct blarg::Optional

pub struct Optional<'a, T> { /* private fields */ }

An option parameter that maps down to Option, taking a single value (precisely 1).

Implementations

impl<'a, T> Optional<'a, T>

pub fn new(variable: &'a mut Option<T>) -> Optional<'a, T>

Create an optional parameter.

Examples found in repository

examples/reducer.rs (line 72)

fn main() {
    let mut _verbose: bool = false;
    let mut operand: Operand = Operand::Add;
    let mut initial: Option<u32> = None;
    let mut _countries: HashSet<Country> = HashSet::default();
    let mut items: Vec<u32> = Vec::default();

    let ap = CommandLineParser::new("reducer");
    let parser = ap
        .add(
            Parameter::option(Switch::new(&mut _verbose, true), "verbose", Some('v'))
                .help("Do dee doo.  We're really stretching here HAAAAAAAA HAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!"),
        )
        .add(
            Parameter::option(Scalar::new(&mut operand), "operand", Some('o'))
                .help("moot")
                .choice(Operand::Add, "+")
                .choice(Operand::Multiply, "*"),
        )
        .add(Parameter::option(Optional::new(&mut initial), "initial", None)
            .meta(vec!["testing a really long meta.. abcdefghijklmnopqrstuvwxyz"])
        )
        .add(Parameter::option(Collection::new(&mut _countries, Nargs::AtLeastOne), "country", None))
        .add(
            Parameter::argument(Collection::new(&mut items, Nargs::AtLeastOne), "item")
                .help("The items."),
        )
        .build();
    parser.parse();
    println!("Items: {items:?}");
    execute(_verbose, operand, initial, _countries, items);
}

examples/foo_bar.rs (line 76)

fn main() {
    let mut verbose: bool = false;
    let mut foo_bar = FooBar::Foo;
    let mut initial: Option<u32> = None;
    let mut countries: HashSet<Country> = HashSet::default();
    let mut items: Vec<u32> = Vec::default();

    let ap = CommandLineParser::new("foo_bar");
    let parser = ap
        .add(
            Parameter::option(Switch::new(&mut verbose, true), "verbose", Some('v'))
                .help("Do dee doo."),
        )
        .branch(
            Condition::new(Scalar::new(&mut foo_bar), "foo_bar")
                .choice(FooBar::Foo, "123 abc let's make this one medium long.")
                .choice(FooBar::Bar, "456 def let's make this one multiple sentences.  We're really stretching here HAAAAAAAA HAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!")
                .help("foo'y bar'y stuff")
                .meta(vec!["a", "b", "c"]),
        )
        .command(FooBar::Foo, |sub| {
            sub.add(Parameter::option(
                Optional::new(&mut initial),
                "initial",
                None,
            ))
            .add(
                Parameter::argument(Collection::new(&mut items, Nargs::Any), "item")
                    .help("The items."),
            )
        })
        .command(FooBar::Bar, |sub| {
            sub.add(Parameter::option(
                Collection::new(&mut countries, Nargs::AtLeastOne),
                "country",
                None,
            ))
        })
        .build();
    parser.parse();
    println!("Items: {items:?}");
    execute(verbose, foo_bar, initial, countries, items);
}

Trait Implementations

impl<'a, T> CliOption for Optional<'a, T>