state management

src/lib.rs

@@ -1,9 +1,12 @@
 pub mod console;
+pub mod rsx;
 pub mod utils;
 pub mod widgets;
 
 pub use std::io::Result;
 
+pub type Element = std::sync::Arc<dyn Fn(&Frame) -> crate::Result<()>>;
+
 pub trait Widget {
     fn render(&self) -> String;
 }
@@ -25,6 +28,8 @@ pub struct Frame {
     pub area: Area,
 }
 
+pub struct State<T>(*mut T);
+
 impl Frame {
     pub fn draw<W>(&self, w: &W, mut props: Area) -> Result<()>
     where
@@ -141,3 +146,85 @@ impl Default for Area {
         }
     }
 }
+
+impl<T: std::fmt::Display> std::fmt::Display for State<T> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", unsafe { &*self.0 })
+    }
+}
+
+impl<T: std::fmt::Debug> std::fmt::Debug for State<T> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "State({:?})", unsafe { &*self.0 })
+    }
+}
+
+//// State ops ////
+
+impl<T: std::ops::Add<Output = T> + Clone> std::ops::Add<T> for State<T> {
+    type Output = T;
+
+    fn add(self, rhs: T) -> Self::Output {
+        unsafe {
+            let lhs = &mut *self.0;
+            lhs.clone() + rhs
+        }
+    }
+}
+
+impl<T: std::ops::Sub<Output = T> + Clone> std::ops::Sub<T> for State<T> {
+    type Output = T;
+
+    fn sub(self, rhs: T) -> Self::Output {
+        unsafe {
+            let lhs = &mut *self.0;
+            lhs.clone() - rhs
+        }
+    }
+}
+
+impl<T: std::ops::Div<Output = T> + Clone> std::ops::Div<T> for State<T> {
+    type Output = T;
+
+    fn div(self, rhs: T) -> Self::Output {
+        unsafe {
+            let lhs = &mut *self.0;
+            lhs.clone() / rhs
+        }
+    }
+}
+
+impl<T: std::ops::AddAssign + Clone> std::ops::AddAssign<T> for State<T> {
+    fn add_assign(&mut self, rhs: T) {
+        unsafe { *self.0 += rhs }
+    }
+}
+
+impl<T: std::ops::SubAssign + Clone> std::ops::SubAssign<T> for State<T> {
+    fn sub_assign(&mut self, rhs: T) {
+        unsafe { *self.0 -= rhs }
+    }
+}
+
+impl<T> std::ops::Deref for State<T> {
+    type Target = T;
+    fn deref(&self) -> &Self::Target {
+        unsafe { &*self.0 }
+    }
+}
+
+impl<T> std::ops::DerefMut for State<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        unsafe { &mut *self.0 }
+    }
+}
+
+impl<T> State<T> {
+    pub fn copy_state(&self) -> Self {
+        Self(self.0)
+    }
+}
+
+pub fn use_state<T>(v: T) -> State<T> {
+    State(Box::into_raw(Box::new(v)))
+}