in midst of refactor

orchidlang/src/utils/take_with_output.rs

@@ -0,0 +1,11 @@
+//! Map over a `&mut` and return an additional value
+
+/// A variation on [take_mut::take] that allows the callback to return a value
+pub fn take_with_output<T, U>(src: &mut T, cb: impl FnOnce(T) -> (T, U)) -> U {
+  take_mut::scoped::scope(|scope| {
+    let (old, hole) = scope.take(src);
+    let (new, out) = cb(old);
+    hole.fill(new);
+    out
+  })
+}