Struct Optional

Source

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

Expand description

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

Implementations§

Source §

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

Source

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

Create an optional parameter.

Examples found in repository ?

examples/reducer.rs (line 72)

53fn main() {
54    let mut _verbose: bool = false;
55    let mut operand: Operand = Operand::Add;
56    let mut initial: Option<u32> = None;
57    let mut _countries: HashSet<Country> = HashSet::default();
58    let mut items: Vec<u32> = Vec::default();
59
60    let ap = CommandLineParser::new("reducer");
61    let parser = ap
62        .add(
63            Parameter::option(Switch::new(&mut _verbose, true), "verbose", Some('v'))
64                .help("Do dee doo.  We're really stretching here HAAAAAAAA HAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!"),
65        )
66        .add(
67            Parameter::option(Scalar::new(&mut operand), "operand", Some('o'))
68                .help("moot")
69                .choice(Operand::Add, "+")
70                .choice(Operand::Multiply, "*"),
71        )
72        .add(Parameter::option(Optional::new(&mut initial), "initial", None)
73            .meta(vec!["testing a really long meta.. abcdefghijklmnopqrstuvwxyz"])
74        )
75        .add(Parameter::option(Collection::new(&mut _countries, Nargs::AtLeastOne), "country", None))
76        .add(
77            Parameter::argument(Collection::new(&mut items, Nargs::AtLeastOne), "item")
78                .help("The items."),
79        )
80        .build();
81    parser.parse();
82    println!("Items: {items:?}");
83    execute(_verbose, operand, initial, _countries, items);
84}

More examples

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examples/foo_bar.rs (line 76)

54fn main() {
55    let mut verbose: bool = false;
56    let mut foo_bar = FooBar::Foo;
57    let mut initial: Option<u32> = None;
58    let mut countries: HashSet<Country> = HashSet::default();
59    let mut items: Vec<u32> = Vec::default();
60
61    let ap = CommandLineParser::new("foo_bar");
62    let parser = ap
63        .add(
64            Parameter::option(Switch::new(&mut verbose, true), "verbose", Some('v'))
65                .help("Do dee doo."),
66        )
67        .branch(
68            Condition::new(Scalar::new(&mut foo_bar), "foo_bar")
69                .choice(FooBar::Foo, "123 abc let's make this one medium long.")
70                .choice(FooBar::Bar, "456 def let's make this one multiple sentences.  We're really stretching here HAAAAAAAA HAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA!")
71                .help("foo'y bar'y stuff")
72                .meta(vec!["a", "b", "c"]),
73        )
74        .command(FooBar::Foo, |sub| {
75            sub.add(Parameter::option(
76                Optional::new(&mut initial),
77                "initial",
78                None,
79            ))
80            .add(
81                Parameter::argument(Collection::new(&mut items, Nargs::Any), "item")
82                    .help("The items."),
83            )
84        })
85        .command(FooBar::Bar, |sub| {
86            sub.add(Parameter::option(
87                Collection::new(&mut countries, Nargs::AtLeastOne),
88                "country",
89                None,
90            ))
91        })
92        .build();
93    parser.parse();
94    println!("Items: {items:?}");
95    execute(verbose, foo_bar, initial, countries, items);
96}