Committing for reference

orchid-base/src/builtin.rs

@@ -0,0 +1,29 @@
+use std::future::Future;
+use std::ops::Deref;
+use std::pin::Pin;
+
+use crate::api;
+
+/// The 3 primary contact points with an extension are
+/// - send a message
+/// - wait for a message to arrive
+/// - wait for the extension to stop after exit (this is the implicit Drop)
+///
+/// There are no ordering guarantees about these
+pub trait ExtPort {
+	fn send(&self, msg: &[u8]) -> Pin<Box<dyn Future<Output = ()>>>;
+	fn recv<'a>(&self, cb: Box<dyn FnOnce(&[u8]) + Send + 'a>) -> Pin<Box<dyn Future<Output = ()>>>;
+}
+
+pub struct ExtInit {
+	pub header: api::ExtensionHeader,
+	pub port: Box<dyn ExtPort>,
+}
+impl ExtInit {
+	pub async fn send(&self, msg: &[u8]) { self.port.send(msg).await }
+	pub async fn recv(&self, cb: impl FnOnce(&[u8]) + Send) { self.port.recv(Box::new(cb)).await }
+}
+impl Deref for ExtInit {
+	type Target = api::ExtensionHeader;
+	fn deref(&self) -> &Self::Target { &self.header }
+}