purrrr

src/model_01.rs

@@ -1,9 +1,9 @@
 use std::{
-    future::Future,
     pin::Pin,
     task::{Context, Poll},
 };
 
+use futures::{future::ready, Future, FutureExt};
 use pin_project::pin_project;
 
 trait More {
@@ -379,26 +379,31 @@ trait TraitInto<A> {
 }
 
 impl<A, I: Impl<Is<A>>> TraitInto<A> for I {
+    #[inline]
     fn trait_into(self) -> A {
         I::method_s(self)
     }
 }
 
+#[repr(transparent)]
 #[pin_project]
 struct TraitFuture<F: ?Sized + Impl<Futures>>(#[pin] F);
 
 impl<F: ?Sized + Impl<Futures>> Future for TraitFuture<F> {
     type Output = F::Associated;
 
+    #[inline]
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         F::method((self.project().0, cx))
     }
 }
 
+#[inline]
 fn aaaaaaa<A>(a: impl Impl<Is<A>>) -> A {
     a.trait_into()
 }
 
+#[inline]
 fn aaaaaa<
     A,
     Ot: ?Sized + OverlayTrait<M::Trait, Associated = Is<A>>,
@@ -411,7 +416,8 @@ fn aaaaaa<
     aaaaaaa::<A>(a)
 }
 
-async fn aaaaa<
+#[inline]
+fn aaaaa<
     A,
     Ot: ?Sized + OverlayTrait<Futures, Associated = Is<A>>,
     Om: ?Sized + OverlayMore<M, Trait = Ot>,
@@ -419,12 +425,11 @@ async fn aaaaa<
     I: ImplOverlay<M> + Impl<Futures> + ImplMember<Futures>,
 >(
     a: I,
-) -> A {
+) -> impl Future<Output = A> {
-    let a = TraitFuture(a).await;
+    TraitFuture(a).map(aaaaaa::<A, Ot, Om, M, I>)
-    let a: <I as ImplOverlayBase<M>>::_Associated = a;
-    aaaaaa::<A, Ot, Om, M, I>(a)
 }
 
+#[inline]
 fn aaaa<
     A,
     Ot: ?Sized + OverlayTrait<Futures, Associated = Is<A>>,
@@ -437,6 +442,7 @@ fn aaaa<
     aaaaa(upcast_ioi_ioia(upcast_im_ioi::<M, _>(a)))
 }
 
+#[inline]
 fn aaa<A>(a: impl Impl<FutureIs<A>>) -> impl Future<Output = A> {
     aaaa(upcast_i_im(a))
 }
@@ -446,6 +452,7 @@ trait TraitIntoFuture<A> {
 }
 
 impl<A, F: Impl<FutureIs<A>>> TraitIntoFuture<A> for F {
+    #[inline]
     fn trait_into_future(self) -> impl Future<Output = A> {
         aaa(self)
     }
@@ -462,23 +469,26 @@ impl Functor for Futures {
     type Trait<A> = FutureIs<A>;
 
     fn pure<A>(a: A) -> impl Impl<Self::Trait<A>> {
-        async { a }
+        ready(a)
     }
 
+    #[inline]
     fn map<A, B>(
         a: impl Impl<Self::Trait<A>>,
         f: impl FnOnce(A) -> B,
     ) -> impl Impl<Self::Trait<B>> {
-        async { f(a.trait_into_future().await) }
+        a.trait_into_future().map(f)
     }
 }
 
+#[inline]
 fn upcast_ioi_ioia<T: ?Sized + More, I: ImplOverlay<T> + Impl<T::Trait>>(
     value: I,
 ) -> impl ImplOverlay<T> + ImplMember<<T::Trait as Trait>::Member> {
     value
 }
 
+#[inline]
 fn upcast_imb_ioi<T: ?Sized + More, I: ImplMoreBase<T>>(
     value: I::MoreTrait,
 ) -> impl ImplOverlay<T> + Impl<T::Trait>
@@ -488,10 +498,12 @@ where
     value
 }
 
+#[inline]
 fn upcast_im_ioi<T: ?Sized + More, I: ImplMore<T>>(value: I) -> impl ImplOverlay<T> {
     upcast_imb_ioi::<T, I>(value)
 }
 
+#[inline]
 fn upcast_ib_im<T: ?Sized + Trait, I: ImplBase<T>>(value: I::More) -> impl ImplMore<T::More>
 where
     <I as ImplBase<T>>::More: Sized,
@@ -499,18 +511,41 @@ where
     value
 }
 
+#[inline]
 fn upcast_i_im<T: ?Sized + Trait, I: Impl<T>>(value: I) -> impl ImplMore<T::More> {
     upcast_ib_im::<T, I>(value)
 }
 
+trait Pure: Sized {
+    fn pure_<F: Functor>(self) -> impl Impl<F::Trait<Self>> {
+        F::pure(self)
+    }
+}
+
+impl<T> Pure for T {}
+
+trait Map<A, B>: Sized {
+    fn map_<F: Functor>(self, f: impl FnOnce(A) -> B) -> impl Impl<F::Trait<B>>
+    where
+        Self: Impl<F::Trait<A>>,
+    {
+        F::map(self, f)
+    }
+}
+
+impl<A, B, T> Map<A, B> for T {}
+
+fn add5_generic<F: Functor>(x: i32) -> impl Impl<F::Trait<i32>> {
+    x.pure_::<F>()
+        .map_::<F>(|x| x + 1)
+        .map_::<F>(|x| x + 1)
+        .map_::<F>(|x| x + 1)
+        .map_::<F>(|x| x + 1)
+        .map_::<F>(|x| x + 1)
+}
+
 pub async fn add5(x: i32) -> i32 {
-    let x = Futures::pure(x);
+    add5_generic::<Futures>(x).trait_into_future().await
-    let x = Futures::map(x, |x| x + 1);
-    let x = Futures::map(x, |x| x + 1);
-    let x = Futures::map(x, |x| x + 1);
-    let x = Futures::map(x, |x| x + 1);
-    let x = Futures::map(x, |x| x + 1);
-    x.trait_into_future().await
 }
 
 #[test]