From 356bbc547eeb14b5d705db2268ea3ffea65b0292 Mon Sep 17 00:00:00 2001
From: Agustin Borgna <agustin.borgna@quantinuum.com>
Date: Tue, 7 Nov 2023 10:36:56 +0000
Subject: [PATCH 1/2] feat: port.as_directed to match on either direction

---
 Cargo.toml  |  1 +
 src/core.rs | 34 ++++++++++++++++------------------
 2 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 1a6df4fd6..1643c110a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -50,6 +50,7 @@ petgraph = { version = "0.6.3", default-features = false }
 context-iterators = "0.2.0"
 serde_json = "1.0.97"
 delegate = "0.10.0"
+either = "1.9.0"
 
 [features]
 pyo3 = ["dep:pyo3"]
diff --git a/src/core.rs b/src/core.rs
index 83bba3ab5..fa9ece839 100644
--- a/src/core.rs
+++ b/src/core.rs
@@ -4,6 +4,7 @@
 
 use derive_more::From;
 
+use either::Either::{self, Left, Right};
 #[cfg(feature = "pyo3")]
 use pyo3::pyclass;
 
@@ -92,35 +93,32 @@ impl Port {
     /// [HugrError::InvalidPortDirection]
     #[inline]
     pub fn as_incoming(&self) -> Result<IncomingPort, HugrError> {
-        match self.direction() {
-            Direction::Incoming => Ok(IncomingPort {
-                index: self.index() as u16,
-            }),
-            dir @ Direction::Outgoing => Err(HugrError::InvalidPortDirection(dir)),
-        }
+        self.as_directed()
+            .left()
+            .ok_or(HugrError::InvalidPortDirection(self.direction()))
     }
 
     /// Converts to an [OutgoingPort] if this port is one; else fails with
     /// [HugrError::InvalidPortDirection]
     #[inline]
     pub fn as_outgoing(&self) -> Result<OutgoingPort, HugrError> {
+        self.as_directed()
+            .right()
+            .ok_or(HugrError::InvalidPortDirection(self.direction()))
+    }
+
+    /// Converts to either an [IncomingPort] or an [OutgoingPort], as appropriate.
+    #[inline]
+    pub fn as_directed(&self) -> Either<IncomingPort, OutgoingPort> {
         match self.direction() {
-            Direction::Outgoing => Ok(OutgoingPort {
+            Direction::Incoming => Left(IncomingPort {
+                index: self.index() as u16,
+            }),
+            Direction::Outgoing => Right(OutgoingPort {
                 index: self.index() as u16,
             }),
-            dir @ Direction::Incoming => Err(HugrError::InvalidPortDirection(dir)),
         }
     }
-    /// Creates a new outgoing port.
-    #[inline]
-    pub fn try_new_outgoing(port: impl TryInto<OutgoingPort>) -> Result<Self, HugrError> {
-        let Ok(port) = port.try_into() else {
-            return Err(HugrError::InvalidPortDirection(Direction::Incoming));
-        };
-        Ok(Self {
-            offset: portgraph::PortOffset::new_outgoing(port.index()),
-        })
-    }
 
     /// Returns the direction of the port.
     #[inline]

From bac80db6cd6f348126b4a1150be9a383becd247e Mon Sep 17 00:00:00 2001
From: Agustin Borgna <agustin.borgna@quantinuum.com>
Date: Tue, 7 Nov 2023 12:32:49 +0000
Subject: [PATCH 2/2] Use itertool's Either, and reexport it

---
 Cargo.toml  | 1 -
 src/core.rs | 4 +++-
 src/lib.rs  | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 1643c110a..1a6df4fd6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -50,7 +50,6 @@ petgraph = { version = "0.6.3", default-features = false }
 context-iterators = "0.2.0"
 serde_json = "1.0.97"
 delegate = "0.10.0"
-either = "1.9.0"
 
 [features]
 pyo3 = ["dep:pyo3"]
diff --git a/src/core.rs b/src/core.rs
index fa9ece839..4df6b52a0 100644
--- a/src/core.rs
+++ b/src/core.rs
@@ -2,9 +2,11 @@
 //!
 //! These types are re-exported in the root of the crate.
 
+pub use itertools::Either;
+
 use derive_more::From;
+use itertools::Either::{Left, Right};
 
-use either::Either::{self, Left, Right};
 #[cfg(feature = "pyo3")]
 use pyo3::pyclass;
 
diff --git a/src/lib.rs b/src/lib.rs
index d1675d6e7..80a7b8edd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -14,7 +14,7 @@
 
 pub mod algorithm;
 pub mod builder;
-mod core;
+pub mod core;
 pub mod extension;
 pub mod hugr;
 pub mod macros;