Add 'Outcome::{ok_map_forward,ok_map_failure}'.

Closes #1622.
This commit is contained in:
Sergio Benitez 2021-05-22 20:37:42 -07:00
parent 2f94c4fbdc
commit 59851a621c
1 changed files with 55 additions and 0 deletions

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@ -597,6 +597,61 @@ impl<S, E, F> Outcome<S, E, F> {
} }
} }
/// Converts `Outcome<S, E, F>` to `Result<S, E>` by identity mapping
/// `Success(S)` and `Failure(E)` to `Result<T, E>` and mapping `Forward(F)`
/// to `Result<T, E>` using `f`.
///
/// ```rust
/// # use rocket::outcome::Outcome;
/// # use rocket::outcome::Outcome::*;
/// #
/// let x: Outcome<i32, &str, usize> = Success(10);
/// assert_eq!(x.ok_map_forward(|x| Ok(x as i32 + 1)), Ok(10));
///
/// let x: Outcome<i32, &str, usize> = Failure("hello");
/// assert_eq!(x.ok_map_forward(|x| Ok(x as i32 + 1)), Err("hello"));
///
/// let x: Outcome<i32, &str, usize> = Forward(0);
/// assert_eq!(x.ok_map_forward(|x| Ok(x as i32 + 1)), Ok(1));
/// ```
#[inline]
pub fn ok_map_forward<M>(self, f: M) -> Result<S, E>
where M: FnOnce(F) -> Result<S, E>
{
match self {
Outcome::Success(s) => Ok(s),
Outcome::Failure(e) => Err(e),
Outcome::Forward(v) => f(v),
}
}
/// Converts `Outcome<S, E, F>` to `Result<S, E>` by identity mapping
/// `Success(S)` and `Forward(F)` to `Result<T, F>` and mapping `Failure(E)`
/// to `Result<T, F>` using `f`.
///
/// ```rust
/// # use rocket::outcome::Outcome;
/// # use rocket::outcome::Outcome::*;
/// #
/// let x: Outcome<i32, &str, usize> = Success(10);
/// assert_eq!(x.ok_map_failure(|s| Ok(123)), Ok(10));
///
/// let x: Outcome<i32, &str, usize> = Failure("hello");
/// assert_eq!(x.ok_map_failure(|s| Ok(123)), Ok(123));
///
/// let x: Outcome<i32, &str, usize> = Forward(0);
/// assert_eq!(x.ok_map_failure(|s| Ok(123)), Err(0));
/// ```
#[inline]
pub fn ok_map_failure<M>(self, f: M) -> Result<S, F>
where M: FnOnce(E) -> Result<S, F>
{
match self {
Outcome::Success(s) => Ok(s),
Outcome::Failure(e) => f(e),
Outcome::Forward(v) => Err(v),
}
}
#[inline] #[inline]
fn formatting(&self) -> (Color, &'static str) { fn formatting(&self) -> (Color, &'static str) {