ResultClass + better lifetimes + less matches

src/func/classes.rs

@@ -1,4 +1,5 @@
 pub mod futureclass;
 pub mod lazyclass;
 pub mod optionclass;
+pub mod resultclass;
 pub mod soloclass;

src/func/classes/futureclass.rs

@@ -71,8 +71,6 @@ impl Monad for FutureClass {
     }
 
     fn join<'a, A: 'a>(ffa: Self::F<'a, Self::F<'a, A>>) -> Self::F<'a, A>
-    where
-        Self::F<'a, A>: 'a,
     {
         Box::pin(async { ffa.await.await })
     }

src/func/classes/lazyclass.rs

@@ -66,8 +66,6 @@ impl Monad for LazyClass {
     }
 
     fn join<'a, A: 'a>(ffa: Self::F<'a, Self::F<'a, A>>) -> Self::F<'a, A>
-    where
-        Self::F<'a, A>: 'a,
     {
         Box::new(|| ffa()())
     }

src/func/classes/optionclass.rs

@@ -21,10 +21,7 @@ impl ApplicativeSeq for OptionClass {
         ff: Self::F<'a, F>,
         fa: Self::F<'a, A>,
     ) -> Self::F<'a, B> {
-        match (ff, fa) {
-            (Some(f), Some(a)) => Some(f(a)),
-            _ => None,
-        }
+        Self::pure(ff?(fa?))
     }
 }
 
@@ -34,10 +31,7 @@ impl ApplicativeLA2 for OptionClass {
         fa: Self::F<'a, A>,
         fb: Self::F<'a, B>,
     ) -> Self::F<'a, C> {
-        match (fa, fb) {
-            (Some(a), Some(b)) => Some(f(a, b)),
-            _ => None,
-        }
+        Self::pure(f(fa?, fb?))
     }
 }
 
@@ -47,17 +41,13 @@ impl Applicative for OptionClass {
     }
 
     fn discard_first<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, B> {
-        match fa {
-            Some(_) => fb,
-            None => None,
-        }
+        fa?;
+        fb
     }
 
     fn discard_second<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, A> {
-        match fb {
-            Some(_) => fa,
-            None => None,
-        }
+        fb?;
+        fa
     }
 }
 
@@ -66,20 +56,11 @@ impl Monad for OptionClass {
         fa: Self::F<'a, A>,
         f: F,
     ) -> Self::F<'a, B> {
-        match fa {
-            Some(a) => f(a),
-            None => None,
-        }
+        f(fa?)
     }
 
-    fn join<'a, A: 'a>(ffa: Self::F<'a, Self::F<'a, A>>) -> Self::F<'a, A>
-    where
-        Self::F<'a, A>: 'a,
-    {
-        match ffa {
-            Some(Some(a)) => Some(a),
-            _ => None,
-        }
+    fn join<'a, A: 'a>(ffa: Self::F<'a, Self::F<'a, A>>) -> Self::F<'a, A> {
+        ffa?
     }
 }
 

src/func/classes/resultclass.rs

@@ -0,0 +1,65 @@
+use crate::func::*;
+
+pub struct ResultClass<E>(E);
+
+impl<E> WeakFunctor for ResultClass<E> {
+    type F<'a, A> = Result<A, E>;
+}
+
+impl<E> Functor for ResultClass<E> {
+    fn fmap<'a, A: 'a, B: 'a, F: 'a + FnOnce(A) -> B>(f: F, fa: Self::F<'a, A>) -> Self::F<'a, B> {
+        fa.map(f)
+    }
+
+    fn replace<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, b: B) -> Self::F<'a, B> {
+        fa.map(|_| b)
+    }
+}
+
+impl<E> ApplicativeSeq for ResultClass<E> {
+    fn seq<'a, A: 'a, B: 'a, F: 'a + FnOnce(A) -> B>(
+        ff: Self::F<'a, F>,
+        fa: Self::F<'a, A>,
+    ) -> Self::F<'a, B> {
+        Self::pure(ff?(fa?))
+    }
+}
+
+impl<E> ApplicativeLA2 for ResultClass<E> {
+    fn la2<'a, A: 'a, B: 'a, C: 'a, F: 'a + FnOnce(A, B) -> C>(
+        f: F,
+        fa: Self::F<'a, A>,
+        fb: Self::F<'a, B>,
+    ) -> Self::F<'a, C> {
+        Self::pure(f(fa?, fb?))
+    }
+}
+
+impl<E> Applicative for ResultClass<E> {
+    fn pure<'a, A: 'a>(a: A) -> Self::F<'a, A> {
+        Ok(a)
+    }
+
+    fn discard_first<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, B> {
+        fa?;
+        fb
+    }
+
+    fn discard_second<'a, A: 'a, B: 'a>(fa: Self::F<'a, A>, fb: Self::F<'a, B>) -> Self::F<'a, A> {
+        fb?;
+        fa
+    }
+}
+
+impl<E> Monad for ResultClass<E> {
+    fn bind<'a, A: 'a, B: 'a, F: 'a + FnOnce(A) -> Self::F<'a, B>>(
+        fa: Self::F<'a, A>,
+        f: F,
+    ) -> Self::F<'a, B> {
+        f(fa?)
+    }
+
+    fn join<'a, A: 'a>(ffa: Self::F<'a, Self::F<'a, A>>) -> Self::F<'a, A> {
+        ffa?
+    }
+}

src/func/classes/soloclass.rs

@@ -65,8 +65,6 @@ impl Monad for SoloClass {
     }
 
     fn join<'a, A: 'a>(ffa: Self::F<'a, Self::F<'a, A>>) -> Self::F<'a, A>
-    where
-        Self::F<'a, A>: 'a,
     {
         ffa
     }