use crate::traits::Functor;
use super::def::Reader;
impl<'a, R, A> Functor<'a, A> for Reader<'a, R, A>
where
R: Clone + 'a,
A: 'a,
{
fn fmap<F, B>(self, f: F) -> Self::Type<B>
where
F: Fn(A) -> B + 'a,
{
Reader::<R, B>::new(move |r| {
let a = self.run(r);
f(a)
})
}
}