input: refactor, move dsl stuff to tek config

input/input.rs

@@ -0,0 +1,77 @@
+#![feature(associated_type_defaults)]
+#![feature(if_let_guard)]
+
+pub(crate) use tengri_core::*;
+
+#[cfg(test)] mod input_test;
+
+/// Event source
+pub trait Input: Sized {
+    /// Type of input event
+    type Event;
+    /// Result of handling input
+    type Handled; // TODO: make this an Option<Box dyn Command<Self>> containing the undo
+    /// Currently handled event
+    fn event (&self) -> &Self::Event;
+    /// Whether component should exit
+    fn is_done (&self) -> bool;
+    /// Mark component as done
+    fn done (&self);
+}
+
+flex_trait_mut!(Handle <E: Input> {
+    fn handle (&mut self, _input: &E) -> Perhaps<E::Handled> {
+        Ok(None)
+    }
+});
+
+pub trait Command<S>: Send + Sync + Sized {
+    fn execute (self, state: &mut S) -> Perhaps<Self>;
+    fn delegate <T> (self, state: &mut S, wrap: impl Fn(Self)->T) -> Perhaps<T>
+        where Self: Sized
+    {
+        Ok(self.execute(state)?.map(wrap))
+    }
+}
+
+impl<S, T: Command<S>> Command<S> for Option<T> {
+    fn execute (self, _: &mut S) -> Perhaps<Self> {
+        Ok(None)
+    }
+    fn delegate <U> (self, _: &mut S, _: impl Fn(Self)->U) -> Perhaps<U>
+        where Self: Sized
+    {
+        Ok(None)
+    }
+}
+
+/// Implement [Command] for given `State` and `handler`
+#[macro_export] macro_rules! command {
+    ($(<$($l:lifetime),+>)?|$self:ident:$Command:ty,$state:ident:$State:ty|$handler:expr) => {
+        impl$(<$($l),+>)? ::tengri::input::Command<$State> for $Command {
+            fn execute ($self, $state: &mut $State) -> Perhaps<Self> {
+                Ok($handler)
+            }
+        }
+    };
+}
+
+/// Implement [Handle] for given `State` and `handler`.
+#[macro_export] macro_rules! handle {
+    (|$self:ident:$State:ty,$input:ident|$handler:expr) => {
+        impl<E: Engine> ::tengri::input::Handle<E> for $State {
+            fn handle (&mut $self, $input: &E) -> Perhaps<E::Handled> {
+                $handler
+            }
+        }
+    };
+    ($E:ty: |$self:ident:$State:ty,$input:ident|$handler:expr) => {
+        impl ::tengri::input::Handle<$E> for $State {
+            fn handle (&mut $self, $input: &$E) ->
+                Perhaps<<$E as ::tengri::input::Input>::Handled>
+            {
+                $handler
+            }
+        }
+    }
+}