use crate::*;
#[derive(Copy, Debug, Clone)]
pub struct Maru;
impl From<()> for Maru {
fn from(_ :()) -> Self { Maru }
}
impl From<Maru> for () {
#[allow(clippy::unused_unit)]
fn from(_ :Maru) -> () { () }
}
impl Judge for bool {
type Positive = Maru;
type Negative = Maru;
fn into_moral (self) -> Moral<Maru, Maru> {
if self { Good(Maru) }
else { Bad(Maru) }
}
fn from_good (_ :Maru) -> Self { true }
fn from_bad (_ :Maru) -> Self { false }
}
impl<T, E, Me> Return for Me where Me: Judge<Positive=T, Negative=E> {
type Value = T;
type Returned = E;
fn into_valret(self) -> ValRet<T, E> {
self.into_moral().into_valret()
}
}
#[cfg(not(feature = "experimental"))]
mod independent {
use crate::*;
impl<T> Judge for Option<T> {
type Positive = T;
type Negative = Maru;
fn into_moral(self) -> Moral<T, Maru> {
match self {
Some(v) => Good(v),
None => Bad(Maru),
}
}
fn from_good(v: T) -> Self { Some(v) }
fn from_bad(_: Maru) -> Self { None }
}
impl<T, E> Judge for Result<T, E> {
type Positive = T;
type Negative = E;
fn into_moral(self) -> Moral<T, E> {
match self {
Ok(v) => Good(v),
Err(e) => Bad(e),
}
}
fn from_good(v: T) -> Self { Ok(v) }
fn from_bad(v: E) -> Self { Err(v) }
}
impl<T, R> Judge for ValRet<T, R> {
type Positive = T;
type Negative = R;
fn into_moral(self) -> Moral<T, R> {
match self {
Val(v) => Good(v),
Ret(r) => Bad(r),
}
}
fn from_good(v: T) -> Self { Val(v) }
fn from_bad(r: R) -> Self { Ret(r) }
}
impl<Y, N> Judge for Moral<Y, N> {
type Positive = Y;
type Negative = N;
fn into_moral(self) -> Moral<Y, N> { self }
fn from_good(v: Y) -> Self { Good(v) }
fn from_bad(v: N) -> Self { Bad(v) }
}
}
#[cfg(feature = "experimental")]
mod nightly {
use core::ops::Try;
use core::option::NoneError;
use crate::*;
impl<T, R> Try for ValRet<T, R> {
type Ok = T;
type Error = R;
fn into_result(self) -> Result<T, R> {
match self {
Val(v) => Ok(v),
Ret(r) => Err(r),
}
}
fn from_ok(v: T) -> Self { Val(v) }
fn from_error(v: R) -> Self { Ret(v) }
}
impl<Y, N> Try for Moral<Y, N> {
type Ok = Y;
type Error = N;
fn into_result(self) -> Result<Y, N> {
Self::into_result(self)
}
fn from_ok(v: Y) -> Self { Good(v) }
fn from_error(v: N) -> Self { Bad(v) }
}
#[macro_export]
macro_rules! impl_judge_from_try {
( $t:ty $(, $i:ident)* $(,)? ) => {
impl<__Y, __N $(, $i)* > $crate::Judge for $t where $t :core::ops::Try<Ok=__Y, Error=__N> {
type Positive = __Y;
type Negative = __N;
fn into_moral(self) -> $crate::Moral<__Y, __N> {
match core::ops::Try::into_result(self) {
Ok(v) => $crate::Moral::Good(v),
Err(e) => $crate::Moral::Bad(e),
}
}
fn from_good(v: __Y) -> Self { core::ops::Try::from_ok(v) }
fn from_bad(v: __N) -> Self { core::ops::Try::from_error(v) }
}
}
}
impl_judge_from_try!(Option<T>, T);
impl_judge_from_try!(Result<T, U>, T, U);
impl_judge_from_try!(Moral<T, U>, T, U);
impl_judge_from_try!(ValRet<T, U>, T, U);
impl From<Maru> for NoneError {
fn from (_ :Maru) -> Self { NoneError }
}
}