monad

library/core/src/monad.fe

@@ -0,0 +1,46 @@
+use self::option::Option
+
+trait Applicative 
+where Self: * -> *
+{
+    fn pure<T>(t: T) -> Self<T>  
+}
+
+impl Applicative for Option {
+    fn pure<T>(t: T) -> Self<T> {
+        Option::Some(t)
+    }
+}
+
+trait Monad: Applicative 
+where Self: * -> * 
+{
+    fn bind<T, F, U>(t: Self<T>) -> Self<U> where F: Fn<T, Self<U>>
+}
+
+impl Monad for Option {
+    fn bind<T, F, U>(t: Self<T>) -> Self<U> where F: Fn<T, Self<U>> {
+        match t {
+            Self::Some(t) => F::exec(t)
+            Self::None => Self::None
+        }
+    }
+}
+
+trait Fn<T, U> {
+    fn exec(t: T) -> U 
+}
+
+type MyFn = ()
+
+impl Fn<bool, Option<u8>> for MyFn {
+    fn exec(t: bool) -> Option<u8> {
+        Option::Some(0)
+    }
+}
+
+#test
+fn my_test() {
+    type OptionU8 = Option<u8>
+    let a = OptionU8::bind<bool, MyFn, u8>(Option::Some(true))
+}

library/core/src/monad/option.fe

@@ -1,4 +1,4 @@
-enum Option<Inner> {
+pub enum Option<Inner> {
     Some(Inner),
     None
 }