use core::fmt::Debug;
#[cfg(feature = "std")]
use std::error::Error;
use crate::{unexpected::Errorable, Exun, RawUnexpected};
mod sealed {
pub trait Sealed {}
impl<T, E> Sealed for Result<T, E> {}
impl<T> Sealed for Option<T> {}
}
use sealed::Sealed;
/// Provides [`Result::unexpect`]
///
/// [`Result::unexpect`]: `ResultErrorExt::unexpect`
#[cfg(feature = "std")]
pub trait ResultErrorExt<T>: Sealed {
/// Converts [`Result<T, E>`] to [`Result<T, RawUnexpected>`].
///
/// # Examples
///
/// ```
/// use exun::*;
/// use core::fmt::Error;
///
/// let res: Result<i32, Error> = Err(Error);
/// let res: Result<i32, RawUnexpected> = res.unexpect();
/// ```
///
/// Use with the try operator
///
/// ```
/// use exun::*;
/// use core::fmt::Error;
///
/// fn foo() -> Result<i32, UnexpectedError> {
/// let res: Result<i32, Error> = Err(Error);
/// Ok(res.unexpect()?)
/// }
/// ```
///
/// Use with the try operator and [`Exun`]
///
/// ```
/// use exun::*;
/// use core::fmt::Error;
///
/// fn foo() -> Result<i32, Exun<(), UnexpectedError>> {
/// let res: Result<i32, Error> = Err(Error);
/// Ok(res.unexpect()?)
/// }
/// ```
///
/// [`Exun`]: `crate::Exun`
#[allow(clippy::missing_errors_doc)]
fn unexpect(self) -> Result<T, RawUnexpected>;
}
#[cfg(feature = "std")]
impl<T, E: Error + Send + Sync + 'static> ResultErrorExt<T> for Result<T, E> {
fn unexpect(self) -> Result<T, RawUnexpected> {
self.map_err(RawUnexpected::new)
}
}
impl<T> ResultErrorExt<T> for Result<T, RawUnexpected> {
fn unexpect(self) -> Self {
self
}
}
impl<T> ResultErrorExt<T> for Option<T> {
fn unexpect(self) -> Result<T, RawUnexpected> {
self.ok_or_else(RawUnexpected::none)
}
}
/// Provides [`Result::unexpect_msg`]
///
/// [`Result::unexpect_msg`]: `ResultMsgExt::unexpect_msg`
pub trait ResultMsgExt<T>: Sealed {
/// Converts [`Result<T, E>`] to [`Result<T, RawUnexpected>`].
///
/// This is provided for compatibility with `no_std`. If your type
/// implements [`Error`], then you should prefer that instead.
///
/// # Examples
///
/// ```
/// use exun::*;
///
/// let res: Result<i32, &str> = Err("failure");
/// let res: Result<i32, RawUnexpected> = res.unexpect_msg();
/// ```
///
/// Use with the try operator
///
/// ```
/// use exun::*;
///
/// fn foo() -> Result<i32, UnexpectedError> {
/// let res: Result<i32, &str> = Err("failure");
/// Ok(res.unexpect_msg()?)
/// }
/// ```
///
/// Use with the try operator and [`Exun`]
///
/// ```
/// use exun::*;
///
/// fn foo() -> Result<i32, Exun<(), UnexpectedError>> {
/// let res: Result<i32, &str> = Err("failure");
/// Ok(res.unexpect_msg()?)
/// }
/// ```
///
/// [`Exun`]: `crate::Exun`
#[allow(clippy::missing_errors_doc)]
fn unexpect_msg(self) -> Result<T, RawUnexpected>;
}
impl<T, E: Errorable + 'static> ResultMsgExt<T> for Result<T, E> {
fn unexpect_msg(self) -> Result<T, RawUnexpected> {
self.map_err(RawUnexpected::msg)
}
}
pub trait ResultExunExt<T, E, U>: Sealed {
/// Converts [`Result<T, Exun<E, U>>`] to [`Option<E>`].
///
/// Converts self into an [`Option<E>`], consuming `self`, and discarding
/// success value and the unexpected error, if any.
///
/// # Examples
///
/// ```
/// use exun::{Expected, Exun, ResultExunExt};
///
/// let x: Result<u32, Exun<&str, &str>> = Ok(2);
/// assert_eq!(x.expected_err(), None);
///
/// let x: Result<u32, Exun<&str, &str>> = Err(Expected("expected"));
/// assert_eq!(x.expected_err(), Some("expected"));
/// ```
fn expected_err(self) -> Option<E>;
/// Converts [`Result<T, Exun<E, U>>`] to [`Option<U>`].
///
/// Converts self into an [`Option<U>`], consuming `self`, and discarding
/// success value and the expected error, if any.
///
/// # Examples
///
/// ```
/// use exun::{Exun, ResultExunExt, Unexpected};
///
/// let x: Result<u32, Exun<&str, &str>> = Ok(2);
/// assert_eq!(x.unexpected_err(), None);
///
/// let x: Result<u32, Exun<&str, &str>> = Err(Unexpected("unexpected"));
/// assert_eq!(x.unexpected_err(), Some("unexpected"));
/// ```
fn unexpected_err(self) -> Option<U>;
/// Maps a [`Result<T, Exun<E, U>>`] to `Result<T, Exun<F, U>>` by applying
/// a function to a contained `Err(Expected)` value, leaving the `Ok` and
/// `Err(Unexpected)` values untouched.
///
/// This function can be used to pass through a successful result while
/// handling an expected error.
///
/// # Examples
///
/// ```
/// use exun::{Exun, ResultExunExt, Expected};
///
/// fn stringify(x: u32) -> String { format!("error code: {x}") }
///
/// let x: Result<u32, Exun<u32, &str>> = Ok(2);
/// assert_eq!(x.map_expected_err(stringify), Ok(2));
///
/// let x: Result<u32, Exun<u32, &str>> = Err(Expected(13));
/// assert_eq!(x.map_expected_err(stringify), Err(Expected("error code: 13".to_string())));
/// ```
fn map_expected_err<F>(self, op: impl FnOnce(E) -> F) -> Result<T, Exun<F, U>>;
/// Maps a [`Result<T, Exun<E, U>>`] to `Result<T, Exun<E, F>>` by applying
/// a function to a contained `Err(Unexpected)` value, leaving the `Ok` and
/// `Err(Expected)` values untouched.
///
/// This function can be used to pass through a successful result while
/// handling an unexpected error.
///
/// # Examples
///
/// ```
/// use exun::{Exun, ResultExunExt, Unexpected};
///
/// fn stringify(x: &str) -> String { format!("error: {x}") }
///
/// let x: Result<u32, Exun<u32, &str>> = Ok(2);
/// assert_eq!(x.map_unexpected_err(stringify), Ok(2));
///
/// let x: Result<u32, Exun<u32, &str>> = Err(Unexpected("hi"));
/// assert_eq!(x.map_unexpected_err(stringify), Err(Unexpected("error: hi".to_string())));
/// ```
fn map_unexpected_err<F>(self, op: impl FnOnce(U) -> F) -> Result<T, Exun<E, F>>;
/// Converts [`Result<T, Exun<E, U>>`] to `Result<T, E>`, consuming the
/// self value.
///
/// Because this function may panic, its use is generally discouraged.
/// Instead, prefer to use pattern matching and handle the [`Unexpected`]
/// case explicitly.
///
/// # Panics
///
/// Panics if the value is an [`Unexpected`], with a panic message provided
/// by the [`Unexpected`]'s value.
///
/// # Examples
///
/// ```
/// use exun::{Exun, ResultExunExt};
///
/// let x: Result<u32, Exun<&str, &str>> = Ok(2);
/// assert_eq!(x.unwrap_result(), Ok(2));
/// ```
///
/// [`Unexpected`]: crate::Unexpected
fn unwrap_result(self) -> Result<T, E>
where
U: Debug;
/// Returns the contained [`Expected`] value, consuming the `self` value.
///
/// Because this function may panic, its use is generally discouraged.
/// Instead, prefer to use pattern matching and handle the [`Unexpected`]
/// case explicitly.
///
/// # Panics
///
/// Panics if the value is an [`Unexpected`], with a panic message provided
/// by the [`Unexpected`]'s value.
///
/// # Examples
///
/// ```
/// use exun::{Expected, Exun, ResultExunExt};
///
/// let x: Result<u32, Exun<&str, &str>> = Err(Expected("failure"));
/// assert_eq!(x.unwrap_expected_err(), "failure");
/// ```
///
/// [`Expected`]: crate::Expected
/// [`Unexpected`]: crate::Unexpected
fn unwrap_expected_err(self) -> E
where
T: Debug,
U: Debug;
/// Returns the contained [`Unexpected`] value, consuming the `self` value.
///
/// Because this function may panic, its use is generally discouraged.
/// Instead, prefer to use pattern matching and handle the [`Expected`]
/// case explicitly.
///
/// # Panics
///
/// Panics if the value is an [`Expected`], with a panic message provided
/// by the [`Expected`]'s value.
///
/// # Examples
///
/// ```
/// use exun::{Exun, ResultExunExt, Unexpected};
///
/// let x: Result<u32, Exun<&str, &str>> = Err(Unexpected("failure"));
/// assert_eq!(x.unwrap_unexpected_err(), "failure");
/// ```
///
/// [`Expected`]: crate::Expected
/// [`Unexpected`]: crate::Unexpected
fn unwrap_unexpected_err(self) -> U
where
T: Debug,
E: Debug;
}
impl<T, E, U> ResultExunExt<T, E, U> for Result<T, Exun<E, U>> {
fn expected_err(self) -> Option<E> {
self.err()?.expected()
}
fn unexpected_err(self) -> Option<U> {
self.err()?.unexpected()
}
fn map_expected_err<F>(self, op: impl FnOnce(E) -> F) -> Result<T, Exun<F, U>> {
self.map_err(|e| e.map(op))
}
fn map_unexpected_err<F>(self, op: impl FnOnce(U) -> F) -> Result<T, Exun<E, F>> {
self.map_err(|e| e.map_unexpected(op))
}
fn unwrap_result(self) -> Result<T, E>
where
U: Debug,
{
match self {
Ok(value) => Ok(value),
Err(error) => Err(error.unwrap()),
}
}
fn unwrap_expected_err(self) -> E
where
T: Debug,
U: Debug,
{
self.unwrap_err().unwrap()
}
fn unwrap_unexpected_err(self) -> U
where
T: Debug,
E: Debug,
{
self.unwrap_err().unwrap_unexpected()
}
}
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