From 8c69cb286ad00b37732805767df229c69a07a8d2 Mon Sep 17 00:00:00 2001
From: Agustin Borgna <agustin.borgna@quantinuum.com>
Date: Fri, 23 Feb 2024 19:08:22 +0000
Subject: [PATCH 1/2] feat: ToffoliBox encoding

---
 src/circuit_json.rs | 21 +++++++++++++++++++++
 src/optype.rs       |  3 +++
 2 files changed, 24 insertions(+)

diff --git a/src/circuit_json.rs b/src/circuit_json.rs
index 32d10ae..6047ce4 100644
--- a/src/circuit_json.rs
+++ b/src/circuit_json.rs
@@ -192,6 +192,17 @@ pub enum OpBox {
         #[serde(default = "default_impl_diag")]
         impl_diag: bool,
     },
+    /// An operation that constructs a circuit to implement the specified
+    /// permutation of classical basis states.
+    ToffoliBox {
+        id: BoxID,
+        /// The classical basis state permutation.
+        permutation: Permutation,
+        strat: ToffoliBoxSynthStrat,
+        #[serde(skip_serializing_if = "Option::is_none")]
+        #[serde(default)]
+        rotation_axis: Option<OpType>,
+    },
 }
 
 fn default_impl_diag() -> bool {
@@ -280,3 +291,13 @@ impl<P> Operation<P> {
         }
     }
 }
+
+/// Strategies for synthesising ToffoliBoxes.
+#[derive(Deserialize, Serialize, Clone, Debug, PartialEq)]
+#[non_exhaustive]
+pub enum ToffoliBoxSynthStrat {
+    /// Use multiplexors to perform parallel swaps on hypercubes.
+    Matching,
+    /// Use CnX gates to perform transpositions.
+    Cycle,
+}
diff --git a/src/optype.rs b/src/optype.rs
index eeef5d2..4ae591e 100644
--- a/src/optype.rs
+++ b/src/optype.rs
@@ -418,6 +418,9 @@ pub enum OpType {
 
     /// See \ref MultiplexedU2Box
     MultiplexedU2Box,
+
+    /// See \ref ToffoliBox
+    ToffoliBox,
 }
 
 #[cfg(feature = "pyo3")]

From 4b0334f95c6064b356f3f797e6271c5f588896ca Mon Sep 17 00:00:00 2001
From: Agustin Borgna <agustin.borgna@quantinuum.com>
Date: Mon, 26 Feb 2024 11:57:58 +0000
Subject: [PATCH 2/2] Add docs

---
 src/circuit_json.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/circuit_json.rs b/src/circuit_json.rs
index 6047ce4..77da8b0 100644
--- a/src/circuit_json.rs
+++ b/src/circuit_json.rs
@@ -198,7 +198,11 @@ pub enum OpBox {
         id: BoxID,
         /// The classical basis state permutation.
         permutation: Permutation,
+        // Synthesis strategy. See [`ToffoliBoxSynthStrat`].
         strat: ToffoliBoxSynthStrat,
+        // The rotation axis of the multiplexors used in the decomposition. Can
+        // be either `Rx` or `Ry`. Only applicable to the
+        // [`ToffoliBoxSynthStrat::Matching`] strategy. Default to `Ry`.
         #[serde(skip_serializing_if = "Option::is_none")]
         #[serde(default)]
         rotation_axis: Option<OpType>,