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use crate::prelude::*;
pub mod hkt {
use core::marker::PhantomData;
use super::*;
pub struct ResultOk<E>(PhantomData<E>);
impl<E> HKT1 for ResultOk<E> {
type T<A> = ::core::result::Result<A, E>;
}
pub struct Result;
impl HKT2 for Result {
type T<A, B> = ::core::result::Result<A, B>;
}
}
pub trait ResultExt<T, E>
where Self: Sized
{
fn swap(self) -> Result<E, T>;
fn recover<R, F>(self, f: F) -> Result<T, R>
where F: F1Once<E, Ret = Result<T, R>>;
fn discard_err<F, B>(self, f: F) -> Result<T, E>
where F: for<'a> F1Once<&'a E, Ret = B>,
B: Discard;
fn filter<P, F>(self, pred: P, on_fail: F) -> Result<T, E>
where P: for<'a> F1Once<&'a T, Ret = bool>,
F: for<'a> F1Once<&'a T, Ret = E>;
fn zip<R, F>(self, f: F) -> Result<(T, R), E>
where F: for<'a> F1Once<&'a T, Ret = Result<R, E>>;
}
impl<T, E> ResultExt<T, E> for Result<T, E> {
fn swap(self) -> Result<E, T> {
match self {
| Ok(t) => Err(t),
| Err(e) => Ok(e),
}
}
fn recover<R, F>(self, f: F) -> Result<T, R>
where F: F1Once<E, Ret = Result<T, R>>
{
match self {
| Ok(t) => Ok(t),
| Err(e) => f.call1(e),
}
}
fn discard_err<F, B>(self, f: F) -> Result<T, E>
where F: for<'a> F1Once<&'a E, Ret = B>,
B: Discard
{
match self {
| Ok(t) => Ok(t),
| Err(e) => {
f.call1(&e);
Err(e)
},
}
}
fn filter<P, F>(self, pred: P, on_fail: F) -> Result<T, E>
where P: for<'a> F1Once<&'a T, Ret = bool>,
F: for<'a> F1Once<&'a T, Ret = E>
{
match self {
| Ok(t) if pred.call1(&t) => Ok(t),
| Ok(t) => Err(on_fail.call1(&t)),
| Err(e) => Err(e),
}
}
fn zip<R, F>(self, f: F) -> Result<(T, R), E>
where F: for<'a> F1Once<&'a T, Ret = Result<R, E>>
{
self.bind1(|t| f.call1(&t).map(|r| (t, r)))
}
}
impl<A, E> FunctorOnce<hkt::ResultOk<E>, A> for Result<A, E> {
fn fmap1<AB, B>(self, f: AB) -> Result<B, E>
where AB: F1Once<A, Ret = B>
{
self.map(|a| f.call1(a))
}
}
deriving!(impl<E> Functor<hkt::ResultOk<E>, A> for Result<A, E> {..FunctorOnce});
impl<AB, E> ApplyOnce<hkt::ResultOk<E>, AB> for Result<AB, E> {
fn apply1<A, B>(self, a: Result<A, E>) -> Result<B, E>
where AB: F1Once<A, Ret = B>
{
match self {
| Ok(f) => a.map(|a| f.call1(a)),
| Err(e) => Err(e),
}
}
}
deriving!(impl<E> Apply<hkt::ResultOk<E>, AB> for Result<AB, E> {..ApplyOnce});
impl<A, E> Applicative<hkt::ResultOk<E>, A> for Result<A, E> {
fn pure(a: A) -> Result<A, E> {
Ok(a)
}
}
impl<A, E> Alt<hkt::ResultOk<E>, A> for Result<A, E> {
fn alt(self, b: Self) -> Self {
self.or(b)
}
}
impl<A, E> FoldableOnce<hkt::ResultOk<E>, A> for Result<A, E> {
fn fold1<B, BAB>(self, f: BAB, b: B) -> B
where BAB: F2Once<B, A, Ret = B>
{
self.ok().fold1(f, b)
}
fn fold1_ref<'a, B, BAB>(&'a self, f: BAB, b: B) -> B
where BAB: F2Once<B, &'a A, Ret = B>,
A: 'a
{
match self {
| Ok(a) => f.call1(b, a),
| Err(_) => b,
}
}
}
deriving!(impl<E> Foldable<hkt::ResultOk<E>, A> for Result<A, E> {..FoldableOnce});
impl<A, B, E> TraversableOnce<hkt::ResultOk<E>, A, B, ()> for Result<A, E>
where hkt::ResultOk<E>: HKT1<T<B> = Result<B, E>> + HKT1<T<A> = Result<A, E>>
{
fn traverse1m<Ap, AtoApOfB>(self, f: AtoApOfB) -> Ap::T<Result<B, E>>
where Ap: HKT1,
Ap::T<B>: Applicative<Ap, B>,
Ap::T<Result<B, E>>: Applicative<Ap, Result<B, E>>,
AtoApOfB: F1Once<A, Ret = Ap::T<B>>
{
match self {
| Ok(a) => f.call1(a).fmap(Ok),
| Err(e) => Ap::T::pure(Err(e)),
}
}
fn traverse11<Ap, AtoApOfB>(self, f: AtoApOfB) -> Ap::T<Result<B, E>>
where Ap: HKT1,
Ap::T<B>: Applicative<Ap, B> + ApplyOnce<Ap, B>,
Ap::T<()>: Applicative<Ap, ()> + ApplyOnce<Ap, ()>,
Ap::T<Result<B, E>>: Applicative<Ap, Result<B, E>> + ApplyOnce<Ap, Result<B, E>>,
AtoApOfB: F1Once<A, Ret = Ap::T<B>>
{
self.traverse1m::<Ap, AtoApOfB>(f)
}
}
deriving!(impl<E> Traversable<hkt::ResultOk<E>, A, B, ()> for Result<A, E> {..TraversableOnce});
impl<A, E> MonadOnce<hkt::ResultOk<E>, A> for Result<A, E> {
fn bind1<B, AMB>(self, f: AMB) -> Result<B, E>
where AMB: F1Once<A, Ret = Result<B, E>>
{
self.and_then(|a| f.call1(a))
}
}
deriving!(impl<E> Monad<hkt::ResultOk<E>, A> for Result<A, E> {..MonadOnce});
impl<A, E> BifunctorOnce<hkt::Result, A, E> for Result<A, E> {
fn bimap1<AB, BB, FA, FB>(self, fa: FA, fb: FB) -> <hkt::Result as HKT2>::T<AB, BB>
where FA: F1Once<A, Ret = AB>,
FB: F1Once<E, Ret = BB>
{
match self {
| Ok(a) => Ok(fa.call1(a)),
| Err(e) => Err(fb.call1(e)),
}
}
}
deriving!(impl Bifunctor<hkt::Result, A, E> for Result<A, E> {..BifunctorOnce});