Struct Switch

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

An option parameter that takes no values (precisely 0).

Implementations

impl<'a, T> Switch<'a, T>

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

Create a switch parameter.

Examples found in repository

examples/example.rs (line 8)

fn main() {
    let mut verbose: bool = false;
    let mut value: u32 = 0;
    let ap = CommandLineParser::new("example");
    let parser = ap
        .add(Parameter::option(
            Switch::new(&mut verbose, true),
            "verbose",
            Some('v'),
        ))
        .add(Parameter::argument(Scalar::new(&mut value), "value").meta(vec!["type: u32"]))
        .build();
    parser.parse();
    println!("value: {value}, verbose: {verbose}");
}

examples/demo_organization.rs (line 36)

fn parse_tokens(parse_fn: impl FnOnce(GeneralParser) -> Result<(), i32>) -> Params {
    let mut params = Params::init();

    let clp = CommandLineParser::new("organization");
    let parser = clp
        .add(Parameter::option(
            Switch::new(&mut params.verbose, true),
            "verbose",
            Some('v'),
        ))
        .add(Parameter::argument(
            Collection::new(&mut params.items, Nargs::AtLeastOne),
            "item",
        ))
        .build();

    // The parse_fn signature is a `Result`.
    // However, since `GeneralParser::parse` does not return an error (it uses `std::process::exit` under the hood), the `Err` case is only reached via test.
    parse_fn(parser).expect("test-reachable-only");
    params
}

examples/reducer.rs (line 63)

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 64)

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);
}

examples/demo_sub_command.rs (line 28)

fn main() {
    let mut sub: u32 = 0;
    let mut arg_0: bool = false;
    let mut opt_0: bool = false;
    let mut arg_1: bool = false;

    let clp = CommandLineParser::new("sub-command");
    let parser = clp
        .about("Describe the base command line parser.  Let's make it a little long for fun.")
        .branch(
            Condition::new(Scalar::new(&mut sub), "sub")
                // "0" is an undocumented sub-command.
                // "1" is a regular sub-command.
                .choice(1, "the one sub-command")
                // "2" is a regular sub-command.
                .choice(2, "the two sub-command")
                // "3" is a false sub-command.
                // It will appear in the documentation, but only those specified via `command(..)` actually affect the program structure.
                .choice(3, "the three sub-command"),
        )
        .command(0, |sub_command| {
            sub_command
                .about("Describe the 0 sub-command parser.  Let's make it a little long for fun.")
                .add(Parameter::argument(Scalar::new(&mut arg_0), "arg"))
                .add(Parameter::option(
                    Switch::new(&mut opt_0, true),
                    "opt",
                    None,
                ))
        })
        .command(1, |sub_command| {
            sub_command
                .about("Describe the 1 sub-command parser.")
                .add(Parameter::argument(Scalar::new(&mut arg_1), "arg"))
        })
        // Specify an argument-less & option-less sub-command by leaving the 'sub' untouched.
        .command(2, |sub_command| sub_command)
        // Since we never add "3", it isn't a true sub-command.
        .build();

    parser.parse();

    println!("Used sub-command '{sub}'.");
    match sub {
        0 => {
            println!("arg_0: {arg_0}");
            println!("opt_0: {opt_0}");
            assert!(!arg_1);
        }
        1 => {
            assert!(!arg_0);
            assert!(!opt_0);
            println!("arg_1: {arg_1}");
        }
        2 => {
            assert!(!arg_0);
            assert!(!opt_0);
            assert!(!arg_1);
            println!("argument-less & option-less");
        }
        _ => {
            panic!(
                "impossible - the parser will reject any variants not specified via `command(..)`."
            )
        }
    }
}

Trait Implementations

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