Trait lifterr::option::OptionExt

source · 
pub trait OptionExt<A> {
    fn then<F, B>(self, f: F) -> Option<B>
    where
        F: FnOnce() -> Option<B>;
    fn inspect<F>(self, f: F) -> Option<A>
    where
        F: FnOnce(&A);
    fn recover_with<F>(self, f: F) -> Option<A>
    where
        F: FnOnce() -> Option<A>;

    fn remap<F, B>(self, f: F) -> Option<B>
    where
        Self: Sized,
        F: FnOnce() -> B,
    { ... }
    fn void(self) -> Option<()>
    where
        Self: Sized,
    { ... }
    fn recover<F>(self, f: F) -> Option<A>
    where
        F: FnOnce() -> A,
        Self: Sized,
    { ... }
}
Expand description

Extension with a set of extra combinators for Option<A>.

Required Methods

Applies f yielding yet another option if Some(x) otherwise propagates None.

use lifterr::option::OptionExt;

fn some() -> Option<i32> { Some(1) }
fn none() -> Option<i32> { None }

assert_eq!(some().then(|| Some("42")), Some("42"));
assert_eq!(none().then(|| Some("42")), None);

Runs f with a reference to A when Some(a).

use lifterr::option::OptionExt;
assert_eq!(Some(10).inspect(|a| println!("a = {a}")), Some(10));

Recovers from an absent value with a partial function.

use lifterr::option::OptionExt;

fn not_found() -> Option<i32> { None }
fn fallback() -> Option<i32> { Some(42) }

assert_eq!(Some(10).recover_with(fallback), Some(10));
assert_eq!(not_found().recover_with(fallback), Some(42));

Provided Methods

Applies f yielding a value which is then wrapped into another option if Some(x) otherwise propagates None.

use lifterr::option::OptionExt;

fn some() -> Option<i32> { Some(1) }
fn none() -> Option<i32> { None }

assert_eq!(some().remap(|| "42"), Some("42"));
assert_eq!(none().remap(|| "42"), None);

Replaces whatever value of type A in Option<A> with an unit.

Recovers from an absent value with a total function.

Implementations on Foreign Types

Implementors