Struct naan::bifunctor::Join

pub struct Join<M, T, A>(_, _);

Join is a newtype that provides a single fmap implementation for Bifunctors that have the same type for both parameters, e.g. Result<A, A> or (A, A).

use naan::prelude::*;

let r = Result::<(), ()>::Ok(()) // Result<(), ()>
                                .join()
                                .fmap(|_| format!("hello!")) // Result<String, String>
                                .unjoin();

assert_eq!(r, Ok(format!("hello!")));

Implementations

impl<M, T, A> Join<M, T, A>

pub fn join(t: T) -> Join<M, T, A>where M: HKT2<T<A, A> = T>,

Wrap a bifunctor in Join

pub fn unjoin(self) -> T

Destroy this Join, yielding the inner type

Trait Implementations

impl<M, T, A> Functor<JoinHKT<M>, A> for Join<M, T, A>where JoinHKT<M>: HKT1<T<A> = Self>, M: HKT2 + HKT2<T<A, A> = T>, T: Bifunctor<M, A, A>,

fn fmap<AB, B>(self, f: AB) -> <JoinHKT<M> as HKT1>::T<B>where AB: F1<A, Ret = B>,

Use a function from A -> B to transform an F<A> to an F<B>.