Struct frunk::traits::Poly

pub struct Poly<T>(pub T);

Wrapper type around a function for polymorphic maps and folds.

This is a thin generic wrapper type that is used to differentiate between single-typed generic closures F that implements, say, Fn(i8) -> bool, and a Poly-typed F that implements multiple Function types via the Func trait. (say, Func<i8, Output=bool> and Func<bool, Output=f32>)

This is needed because there are completely generic impls for many of the HList traits that take a simple unwrapped closure.

Trait Implementations

impl<T> Clone for Poly<T> where
    T: Clone, 

pub fn clone(&self) -> Poly<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<P, R, CH, CTail> CoproductFoldable<Poly<P>, R> for Coproduct<CH, CTail> where
    P: Func<CH, Output = R>,
    CTail: CoproductFoldable<Poly<P>, R>, 

pub fn fold(self, f: Poly<P>) -> R

Use functions to fold a coproduct into a single value.

impl<T> Debug for Poly<T> where
    T: Debug, 

pub fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<T> Default for Poly<T> where
    T: Default, 

pub fn default() -> Poly<T>

Returns the “default value” for a type.

impl<P, R, H, Tail, Acc> HFoldLeftable<Poly<P>, Acc> for HCons<H, Tail> where
    P: Func<(Acc, H), Output = R>,
    Tail: HFoldLeftable<Poly<P>, R>, 

type Output = <Tail as HFoldLeftable<Poly<P>, R>>::Output

pub fn foldl(
    self,
    poly: Poly<P>,
    acc: Acc
) -> <HCons<H, Tail> as HFoldLeftable<Poly<P>, Acc>>::Output

Perform a left fold over an HList.

impl<P, R, H, Tail, Init> HFoldRightable<Poly<P>, Init> for HCons<H, Tail> where
    P: Func<(<Tail as HFoldRightable<Poly<P>, Init>>::Output, H), Output = R>,
    Tail: HFoldRightable<Poly<P>, Init>, 

type Output = R

pub fn foldr(
    self,
    poly: Poly<P>,
    init: Init
) -> <HCons<H, Tail> as HFoldRightable<Poly<P>, Init>>::Output

Perform a right fold over an HList.

impl<P, H, Tail> HMappable<Poly<P>> for HCons<H, Tail> where
    P: Func<H>,
    Tail: HMappable<Poly<P>>, 

type Output = HCons<<P as Func<H>>::Output, <Tail as HMappable<Poly<P>>>::Output>

pub fn map(
    self,
    poly: Poly<P>
) -> <HCons<H, Tail> as HMappable<Poly<P>>>::Output

Apply a function to each element of an HList.

impl<T> Copy for Poly<T> where
    T: Copy,