ApplicativeSelect

book-monads

@@ -1 +1 @@
-Subproject commit 58487121898c8da9c51479f1df4c1055c7df1e6d
+Subproject commit 80aa72c60ecd0ac605041d22df2ea6a66178c5be

src/func.rs

@@ -7,6 +7,7 @@
 //! * <https://hackage.haskell.org/package/base-4.18.0.0/docs/Control-Applicative.html>
 //! * <https://hackage.haskell.org/package/base-4.18.0.0/docs/Control-Monad.html>
 
+mod applicative_select;
 pub mod classes;
 pub mod clone_func;
 mod controlflow;
@@ -21,6 +22,7 @@ pub use std::ops::ControlFlow;
 
 pub use radn_derive::{CovariantFunctor, SharedFunctor};
 
+pub use self::applicative_select::{ApplicativeSelect, Selected};
 pub use self::controlflow::{AIterative, AIterativeWrapped, Iterative, IterativeWrapped};
 use self::controlflow::{ArgumentedIterative, BindableMut, ControlFlowClass};
 

src/func/applicative_select.rs

@@ -0,0 +1,16 @@
+use super::*;
+
+pub enum Selected<'a, A: 'a, B: 'a, T: ?Sized + 'a + WeakFunctor> {
+    A(A, T::F<'a, B>),
+    B(T::F<'a, A>, B),
+}
+
+pub trait ApplicativeSelect: Functor {
+    fn select<'a, A: 'a, B: 'a, C: 'a>(
+        f: impl 'a + FnOnce(Selected<'a, A, B, Self>) -> C,
+        fa: Self::F<'a, A>,
+        fb: Self::F<'a, B>,
+    ) -> Self::F<'a, C>
+    where
+        Self: 'a;
+}