improved LocalFunctor

src/func.rs

@@ -228,7 +228,7 @@ pub trait LocalFunctor: WeakFunctor {
         Self: 'a;
 
     /// Stuff wrapped result into another functor.
-    fn stuff<'a, A: 'a, U: 'a + Functor>(fa: Self::F<'a, U::F<'a, A>>) -> U::F<'a, Self::F<'a, A>>
+    fn stuff<'a, A: 'a, T: 'a + Pure>(fa: Self::F<'a, T::F<'a, A>>) -> T::F<'a, Self::F<'a, A>>
     where
         Self: 'a;
 }

src/func/classes/composition.rs

@@ -120,3 +120,19 @@ impl<U: Monad, V: Monad + LocalFunctor> Monad for CompositionClass<U, V> {
         U::join(U::fmap(|ufa| U::fmap(V::join, V::stuff::<_, U>(ufa)), ffa))
     }
 }
+
+impl<U: LocalFunctor + Functor, V: LocalFunctor> LocalFunctor for CompositionClass<U, V> {
+    fn unstuff<'a, A: 'a, B: 'a>(state: Self::F<'a, IState<A, B>>) -> IState<A, Self::F<'a, B>>
+    where
+        Self: 'a,
+    {
+        U::unstuff(U::fmap(V::unstuff, state))
+    }
+
+    fn stuff<'a, A: 'a, T: 'a + Pure>(fa: Self::F<'a, T::F<'a, A>>) -> T::F<'a, Self::F<'a, A>>
+    where
+        Self: 'a,
+    {
+        U::stuff::<_, T>(U::fmap(V::stuff::<_, T>, fa))
+    }
+}

src/func/classes/option.rs

@@ -99,6 +99,29 @@ impl Monad for OptionClass {
     }
 }
 
+impl LocalFunctor for OptionClass {
+    fn unstuff<'a, A: 'a, B: 'a>(state: Self::F<'a, IState<A, B>>) -> IState<A, Self::F<'a, B>>
+    where
+        Self: 'a,
+    {
+        match state {
+            Some(IState::Pending(a)) => IState::Pending(a),
+            Some(IState::Done(b)) => IState::Done(Some(b)),
+            None => IState::Done(None),
+        }
+    }
+
+    fn stuff<'a, A: 'a, T: 'a + Pure>(fa: Self::F<'a, T::F<'a, A>>) -> T::F<'a, Self::F<'a, A>>
+    where
+        Self: 'a,
+    {
+        match fa {
+            Some(ua) => T::fmap(Some, ua),
+            None => T::pure(None),
+        }
+    }
+}
+
 #[cfg(test)]
 mod option_tests {
     use super::{test_suite, tests, Functor};

src/func/classes/result.rs

@@ -9,24 +9,33 @@
 
 use crate::func::*;
 
-pub struct ResultClass<E: 'static>(E);
+pub struct ResultClass<E>(E);
 
 impl<E> WeakFunctor for ResultClass<E> {
-    type F<'a, A: 'a> = Result<A, E>;
+    type F<'a, A: 'a> = Result<A, E> where Self: 'a;
 }
 
 impl<E> Functor for ResultClass<E> {
-    fn fmap<'a, A: 'a, B: 'a>(f: impl 'a + FnOnce(A) -> B, fa: Self::F<'a, A>) -> Self::F<'a, B> {
+    fn fmap<'a, A: 'a, B: 'a>(f: impl 'a + FnOnce(A) -> B, fa: Self::F<'a, A>) -> Self::F<'a, B>
+    where
+        Self: 'a,
+    {
         fa.map(f)
     }
 
-    fn replace<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, b: B) -> Self::F<'a, B> {
+    fn replace<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, b: B) -> Self::F<'a, B>
+    where
+        Self: 'a,
+    {
         fa.map(|_| b)
     }
 }
 
 impl<E> Pure for ResultClass<E> {
-    fn pure<'a, A: 'a>(a: A) -> Self::F<'a, A> {
+    fn pure<'a, A: 'a>(a: A) -> Self::F<'a, A>
+    where
+        Self: 'a,
+    {
         Ok(a)
     }
 }
@@ -35,7 +44,10 @@ impl<E> ApplicativeSeq for ResultClass<E> {
     fn seq<'a, A: 'a, B: 'a>(
         ff: Self::F<'a, impl 'a + FnOnce(A) -> B>,
         fa: Self::F<'a, A>,
-    ) -> Self::F<'a, B> {
+    ) -> Self::F<'a, B>
+    where
+        Self: 'a,
+    {
         Self::pure(ff?(fa?))
     }
 }
@@ -45,7 +57,10 @@ impl<E> ApplicativeLA2 for ResultClass<E> {
         f: impl 'a + FnOnce(A, B) -> C,
         fa: Self::F<'a, A>,
         fb: Self::F<'a, B>,
-    ) -> Self::F<'a, C> {
+    ) -> Self::F<'a, C>
+    where
+        Self: 'a,
+    {
         Self::pure(f(fa?, fb?))
     }
 }
@@ -60,12 +75,18 @@ impl<E> ApplicativeTuple for ResultClass<E> {
 }
 
 impl<E> Applicative for ResultClass<E> {
-    fn discard_first<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, B> {
+    fn discard_first<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, B>
+    where
+        Self: 'a,
+    {
         fa?;
         fb
     }
 
-    fn discard_second<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, A> {
+    fn discard_second<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, A>
+    where
+        Self: 'a,
+    {
         fb?;
         fa
     }
@@ -75,7 +96,10 @@ impl<E> Monad for ResultClass<E> {
     fn bind<'a, A: 'a, B: 'a>(
         fa: Self::F<'a, A>,
         f: impl 'a + FnOnce(A) -> Self::F<'a, B>,
-    ) -> Self::F<'a, B> {
+    ) -> Self::F<'a, B>
+    where
+        Self: 'a,
+    {
         f(fa?)
     }
 
@@ -94,11 +118,37 @@ impl<E> Monad for ResultClass<E> {
         }
     }
 
-    fn join<'a, A: 'a>(ffa: Self::F<'a, Self::F<'a, A>>) -> Self::F<'a, A> {
+    fn join<'a, A: 'a>(ffa: Self::F<'a, Self::F<'a, A>>) -> Self::F<'a, A>
+    where
+        Self: 'a,
+    {
         ffa?
     }
 }
 
+impl<E> LocalFunctor for ResultClass<E> {
+    fn unstuff<'a, A: 'a, B: 'a>(state: Self::F<'a, IState<A, B>>) -> IState<A, Self::F<'a, B>>
+    where
+        Self: 'a,
+    {
+        match state {
+            Ok(IState::Pending(a)) => IState::Pending(a),
+            Ok(IState::Done(b)) => IState::Done(Ok(b)),
+            Err(e) => IState::Done(Err(e)),
+        }
+    }
+
+    fn stuff<'a, A: 'a, T: 'a + Pure>(fa: Self::F<'a, T::F<'a, A>>) -> T::F<'a, Self::F<'a, A>>
+    where
+        Self: 'a,
+    {
+        match fa {
+            Ok(ua) => T::fmap(Ok, ua),
+            Err(e) => T::pure(Err(e)),
+        }
+    }
+}
+
 impl<E> MonadFail<E> for ResultClass<E> {
     fn fail<'a, A: 'a>(e: E) -> Self::F<'a, A>
     where

src/func/classes/solo.rs

@@ -98,3 +98,19 @@ impl Monad for SoloClass {
         ffa
     }
 }
+
+impl LocalFunctor for SoloClass {
+    fn unstuff<'a, A: 'a, B: 'a>(state: Self::F<'a, IState<A, B>>) -> IState<A, Self::F<'a, B>>
+    where
+        Self: 'a,
+    {
+        state
+    }
+
+    fn stuff<'a, A: 'a, T: 'a + Pure>(fa: Self::F<'a, T::F<'a, A>>) -> T::F<'a, Self::F<'a, A>>
+    where
+        Self: 'a,
+    {
+        fa
+    }
+}