repline: Promote to its own crate!

cl-repl: Major refactor based on the design of typeck.rs

repline/src/raw.rs

@@ -0,0 +1,21 @@
+//! Sets the terminal to [`raw`] mode for the duration of the returned object's lifetime.
+
+/// Sets the terminal to raw mode for the duration of the returned object's lifetime.
+pub fn raw() -> impl Drop {
+    Raw::default()
+}
+struct Raw();
+impl Default for Raw {
+    fn default() -> Self {
+        std::thread::yield_now();
+        crossterm::terminal::enable_raw_mode()
+            .expect("should be able to transition into raw mode");
+        Raw()
+    }
+}
+impl Drop for Raw {
+    fn drop(&mut self) {
+        crossterm::terminal::disable_raw_mode()
+            .expect("should be able to transition out of raw mode");
+    }
+}