move the send and turn row markers into hive-types

hive-types/src/lib.rs

@@ -1,4 +1,5 @@
-//! Foundational shared types for the hyperhive workspace: [`Ident`] and [`Permission`].
+//! Foundational shared types for the hyperhive workspace: [`Ident`], [`Permission`]
+//! and the [`term_msg`] row markers.
 //!
 //! A zero-dependency (bar `serde`) leaf crate so every wire-type crate
 //! (`hive-sh4re`, `hive-host-sock`, `hive-core-agent-sock`) and both binaries
@@ -10,6 +11,8 @@ mod permission;
 
 pub use permission::Permission;
 
+pub mod term_msg;
+
 /// The environment variable nix uses to hand this process the blacklist of
 /// names that already mean something to the message layer.
 ///

hive-types/src/term_msg.rs

@@ -0,0 +1,72 @@
+//! The icons and summary prefixes that mark a terminal row as a sent message
+//! or a message-started turn, and the parsers that read the peer back out.
+//!
+//! The classifier in `hive-sh4re` builds the summaries and
+//! `swarm-controller`'s message stream parses them, so both sides name the
+//! same constants and the same parsers rather than each spelling the format.
+
+/// Icon of the row an agent's `send` tool call makes.
+pub const SEND_ICON: &str = "📤";
+
+/// What a `send` row's summary starts with; the recipient follows. A
+/// multi-line body appends ` · <N>L`, which [`send_recipient`] drops.
+pub const SEND_SUMMARY_PREFIX: &str = "send* → ";
+
+/// Icon of the row a turn started by a message makes.
+pub const TURN_ICON: &str = "◆";
+
+/// What a turn-start row's summary starts with; the sender follows.
+pub const TURN_SUMMARY_PREFIX: &str = "TURN ← ";
+
+/// The recipient a `send` row's summary names, without the line-count suffix.
+#[must_use]
+pub fn send_recipient(summary: &str) -> Option<&str> {
+    let rest = summary.strip_prefix(SEND_SUMMARY_PREFIX)?;
+    Some(match rest.rsplit_once(" · ") {
+        Some((to, lines))
+            if lines
+                .strip_suffix('L')
+                .is_some_and(|n| !n.is_empty() && n.bytes().all(|b| b.is_ascii_digit())) =>
+        {
+            to
+        }
+        _ => rest,
+    })
+}
+
+/// The sender a turn-start row's summary names.
+#[must_use]
+pub fn turn_sender(summary: &str) -> Option<&str> {
+    summary.strip_prefix(TURN_SUMMARY_PREFIX)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{SEND_SUMMARY_PREFIX, TURN_SUMMARY_PREFIX, send_recipient, turn_sender};
+
+    #[test]
+    fn a_send_summary_names_its_recipient_with_and_without_the_line_count() {
+        assert_eq!(
+            send_recipient(&format!("{SEND_SUMMARY_PREFIX}iris")),
+            Some("iris")
+        );
+        assert_eq!(
+            send_recipient(&format!("{SEND_SUMMARY_PREFIX}iris · 3L")),
+            Some("iris")
+        );
+        assert_eq!(send_recipient("send* →"), None);
+        assert_eq!(send_recipient("Read(x)"), None);
+        // A suffix lookalike in the name is not stripped.
+        assert_eq!(send_recipient("send* → a · xL"), Some("a · xL"));
+    }
+
+    #[test]
+    fn a_turn_summary_names_its_sender() {
+        assert_eq!(
+            turn_sender(&format!("{TURN_SUMMARY_PREFIX}atlas")),
+            Some("atlas")
+        );
+        assert_eq!(turn_sender("TURN ←"), None);
+        assert_eq!(turn_sender("send* → iris"), None);
+    }
+}