wip: big flat pt.2: extract engine crate

engine/src/lib.rs

@@ -0,0 +1,62 @@
+mod component; pub use self::component::*;
+mod engine;    pub use self::engine::*;
+mod input;     pub use self::input::*;
+mod output;    pub use self::output::*;
+mod tui;       pub use self::tui::*;
+
+pub use std::error::Error;
+
+/// Standard result type.
+pub type Usually<T> = Result<T, Box<dyn Error>>;
+
+/// Standard optional result type.
+pub type Perhaps<T> = Result<Option<T>, Box<dyn Error>>;
+
+#[cfg(test)] #[test] fn test_stub_engine () -> Usually<()> {
+    struct TestEngine(bool);
+    struct TestInput(bool);
+    struct TestOutput([u16;4]);
+    enum TestEvent { Test1 }
+    impl Engine for TestEngine {
+        type Input   = TestInput;
+        type Handled = ();
+        type Output  = TestOutput;
+        type Unit    = u16;
+        type Size    = [u16;2];
+        type Area    = [u16;4];
+        fn exited (&self) -> bool {
+            self.0
+        }
+    }
+    impl Input<TestEngine> for TestInput {
+        type Event = TestEvent;
+        fn event (&self) -> &Self::Event {
+            &TestEvent::Test1
+        }
+        fn is_done (&self) -> bool {
+            self.0
+        }
+        fn done (&self) {}
+    }
+    impl Output<TestEngine> for TestOutput {
+        fn area (&self) -> [u16;4] {
+            self.0
+        }
+        fn area_mut (&mut self) -> &mut [u16;4] {
+            &mut self.0
+        }
+        fn render_in (&mut self, _: [u16;4], _: &dyn Render<TestEngine>) -> Usually<()> {
+            Ok(())
+        }
+    }
+    impl Render<TestEngine> for String {
+        fn min_size (&self, _: [u16;2]) -> Perhaps<[u16;2]> {
+            Ok(Some([self.len() as u16, 1]))
+        }
+    }
+    Ok(())
+}
+
+#[cfg(test)] #[test] fn test_tui_engine () -> Usually<()> {
+    Ok(())
+}