feat: drop pyo3 core dep (#355)

Adds a python-side definition of `Tk2Op` and `Pauli`, so we can drop the
dependency on `pyo3` from the main rust package.

In addition of being necessary for #350, having only one package
depending on `pyo3` removes building headaches due to it linking to
python multiple times.

Blocked by #352

README.md

@@ -56,9 +56,6 @@ tket2::passes::apply_greedy_commutation(&mut circ);
 
 ## Features
 
-- `pyo3`
-  Enables some python bindings via pyo3. See the `tket2-py` folder for more.
-
 - `portmatching`
   Enables pattern matching using the `portmatching` crate.
 

justfile

@@ -18,11 +18,9 @@ build:
 
 # Run all the tests.
 test language="[rust|python]" : (_run_lang language \
-        "poetry run cargo test --all-features" \
+        "poetry run cargo test --all-features --workspace" \
         "poetry run maturin develop && poetry run pytest"
     )
-# Note: We cannot use `cargo test --workspace` because there
-# are two crates that use pyo3, and that causes a linking conflict.
 
 # Auto-fix all clippy warnings.
 fix language="[rust|python]": (_run_lang language \

tket2-py/Cargo.toml

@@ -18,7 +18,7 @@ test = false
 bench = false
 
 [dependencies]
-tket2 = { workspace = true, features = ["pyo3", "portmatching"] }
+tket2 = { workspace = true, features = ["portmatching"] }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
 tket-json-rs = { workspace = true, features = ["pyo3"] }
@@ -29,3 +29,4 @@ num_cpus = { workspace = true }
 derive_more = { workspace = true }
 itertools = { workspace = true }
 portmatching = { workspace = true }
+strum = { workspace = true }

tket2-py/src/circuit.rs

@@ -38,10 +38,8 @@ pub fn module(py: Python<'_>) -> PyResult<Bound<'_, PyModule>> {
     m.add_class::<PyWire>()?;
     m.add_class::<WireIter>()?;
     m.add_class::<PyCircuitCost>()?;
-    m.add_class::<Tk2Op>()?;
     m.add_class::<PyCustom>()?;
     m.add_class::<PyHugrType>()?;
-    m.add_class::<Pauli>()?;
     m.add_class::<PyTypeBound>()?;
 
     m.add_function(wrap_pyfunction!(validate_hugr, &m)?)?;

tket2-py/src/circuit/tk2circuit.rs

@@ -25,6 +25,7 @@ use tket2::passes::CircuitChunks;
 use tket2::{Circuit, Tk2Op};
 use tket_json_rs::circuit_json::SerialCircuit;
 
+use crate::ops::PyTk2Op;
 use crate::rewrite::PyCircuitRewrite;
 use crate::utils::ConvertPyErr;
 
@@ -127,7 +128,8 @@ impl Tk2Circuit {
                     "Could not convert circuit operation to a `Tk2Op`: {e}"
                 ))
             })?;
-            let cost = cost_fn.call1((tk2_op,))?;
+            let tk2_py_op = PyTk2Op::from(tk2_op);
+            let cost = cost_fn.call1((tk2_py_op,))?;
             Ok(PyCircuitCost {
                 cost: cost.to_object(py),
             })

tket2-py/src/lib.rs

@@ -1,5 +1,6 @@
 //! Python bindings for TKET2.
 pub mod circuit;
+pub mod ops;
 pub mod optimiser;
 pub mod passes;
 pub mod pattern;
@@ -12,6 +13,7 @@ use pyo3::prelude::*;
 #[pymodule]
 fn _tket2(py: Python, m: &Bound<PyModule>) -> PyResult<()> {
     add_submodule(py, m, circuit::module(py)?)?;
+    add_submodule(py, m, ops::module(py)?)?;
     add_submodule(py, m, optimiser::module(py)?)?;
     add_submodule(py, m, passes::module(py)?)?;
     add_submodule(py, m, pattern::module(py)?)?;

tket2-py/src/ops.rs

@@ -0,0 +1,202 @@
+//! Bindings for rust-defined operations
+
+use derive_more::From;
+use hugr::ops::NamedOp;
+use pyo3::prelude::*;
+use std::str::FromStr;
+use strum::IntoEnumIterator;
+use tket2::{Pauli, Tk2Op};
+
+/// The module definition
+pub fn module(py: Python<'_>) -> PyResult<Bound<'_, PyModule>> {
+    let m = PyModule::new_bound(py, "ops")?;
+    m.add_class::<PyTk2Op>()?;
+    m.add_class::<PyPauli>()?;
+    Ok(m)
+}
+
+/// Enum of Tket2 operations in hugr.
+///
+/// Python equivalent of [`Tk2Op`].
+///
+/// [`Tk2Op`]: tket2::ops::Tk2Op
+#[pyclass]
+#[pyo3(name = "Tk2Op")]
+#[derive(Debug, Clone, From)]
+#[repr(transparent)]
+pub struct PyTk2Op {
+    /// Rust representation of the operation.
+    pub op: Tk2Op,
+}
+
+#[pymethods]
+impl PyTk2Op {
+    /// Initialize a new `PyTk2Op` from a python string.
+    #[new]
+    fn new(op: &str) -> PyResult<Self> {
+        Ok(Self {
+            op: Tk2Op::from_str(op)
+                .map_err(|e| PyErr::new::<pyo3::exceptions::PyValueError, _>(e.to_string()))?,
+        })
+    }
+
+    /// Iterate over the operations.
+    #[staticmethod]
+    pub fn values() -> PyTk2OpIter {
+        PyTk2OpIter { it: Tk2Op::iter() }
+    }
+
+    /// Get the string name of the operation.
+    #[getter]
+    pub fn name(&self) -> String {
+        self.op.name().to_string()
+    }
+
+    /// Get the qualified name of the operation, including the extension.
+    #[getter]
+    pub fn qualified_name(&self) -> String {
+        self.op.exposed_name().to_string()
+    }
+
+    /// String representation of the operation.
+    pub fn __repr__(&self) -> String {
+        self.qualified_name()
+    }
+
+    /// String representation of the operation.
+    pub fn __str__(&self) -> String {
+        self.name()
+    }
+
+    /// Check if two operations are equal.
+    pub fn __eq__(&self, other: &PyTk2Op) -> bool {
+        self.op == other.op
+    }
+}
+
+/// Iterator over the operations.
+#[pyclass]
+#[pyo3(name = "Tk2OpIter")]
+#[derive(Debug, Clone)]
+#[repr(transparent)]
+pub struct PyTk2OpIter {
+    /// Iterator over the operations.
+    pub it: <Tk2Op as IntoEnumIterator>::Iterator,
+}
+
+#[pymethods]
+impl PyTk2OpIter {
+    /// Iterate over the operations.
+    fn __iter__(slf: PyRef<'_, Self>) -> PyRef<'_, Self> {
+        slf
+    }
+
+    /// Get the next operation.
+    pub fn __next__(&mut self) -> Option<PyTk2Op> {
+        self.it.next().map(|op| PyTk2Op { op })
+    }
+}
+
+/// Pauli matrices
+///
+/// Python equivalent of [`Pauli`].
+///
+/// [`Pauli`]: tket2::ops::Pauli
+#[pyclass]
+#[pyo3(name = "Pauli")]
+#[derive(Debug, Clone, From)]
+#[repr(transparent)]
+pub struct PyPauli {
+    /// Rust representation of the pauli matrix.
+    pub p: Pauli,
+}
+
+#[pymethods]
+impl PyPauli {
+    /// Initialize a new `PyPauli` from a python string.
+    #[new]
+    fn new(p: &str) -> PyResult<Self> {
+        Ok(Self {
+            p: Pauli::from_str(p)
+                .map_err(|e| PyErr::new::<pyo3::exceptions::PyValueError, _>(e.to_string()))?,
+        })
+    }
+
+    /// Iterate over the pauli matrices.
+    #[staticmethod]
+    pub fn values() -> PyPauliIter {
+        PyPauliIter { it: Pauli::iter() }
+    }
+
+    /// Return the Pauli matrix as a string.
+    #[getter]
+    pub fn name(&self) -> String {
+        format!("{}", self.p)
+    }
+
+    /// Pauli identity matrix.
+    #[staticmethod]
+    #[pyo3(name = "I")]
+    fn i() -> Self {
+        Self { p: Pauli::I }
+    }
+
+    /// Pauli X matrix.
+    #[staticmethod]
+    #[pyo3(name = "X")]
+    fn x() -> Self {
+        Self { p: Pauli::X }
+    }
+
+    /// Pauli Y matrix.
+    #[staticmethod]
+    #[pyo3(name = "Y")]
+    fn y() -> Self {
+        Self { p: Pauli::Y }
+    }
+
+    /// Pauli Z matrix.
+    #[pyo3(name = "Z")]
+    #[staticmethod]
+    fn z() -> Self {
+        Self { p: Pauli::Z }
+    }
+
+    /// String representation of the Pauli matrix.
+    pub fn __repr__(&self) -> String {
+        format!("{:?}", self.p)
+    }
+
+    /// String representation of the Pauli matrix.
+    pub fn __str__(&self) -> String {
+        format!("{}", self.p)
+    }
+
+    /// Check if two Pauli matrices are equal.
+    pub fn __eq__(&self, other: &PyPauli) -> bool {
+        self.p == other.p
+    }
+}
+
+/// Iterator over the Pauli matrices.
+#[pyclass]
+#[pyo3(name = "PauliIter")]
+#[derive(Debug, Clone)]
+#[repr(transparent)]
+pub struct PyPauliIter {
+    /// Iterator over the Pauli matrices.
+    pub it: <Pauli as IntoEnumIterator>::Iterator,
+}
+
+#[pymethods]
+impl PyPauliIter {
+    /// Iterate over the operations.
+    fn __iter__(slf: PyRef<'_, Self>) -> PyRef<'_, Self> {
+        slf
+    }
+
+    /// Get the next Pauli matrix.
+    pub fn __next__(&mut self) -> Option<PyPauli> {
+        self.it.next().map(|p| PyPauli { p })
+    }
+}

tket2-py/test/test_circuit.py

@@ -4,9 +4,9 @@
 
 from tket2.circuit import (
     Tk2Circuit,
-    Tk2Op,
     to_hugr_dot,
 )
+from tket2.ops import Tk2Op
 
 
 @dataclass

tket2-py/test/test_ops.py

@@ -0,0 +1,18 @@
+import tket2
+from tket2.ops import Tk2Op, Pauli
+
+
+def test_ops_roundtrip():
+    for op in Tk2Op:
+        assert Tk2Op._from_rs(op._to_rs()) == op
+
+    for op in tket2._tket2.ops.Tk2Op.values():
+        assert Tk2Op._from_rs(op)._to_rs() == op
+
+
+def test_pauli_roundtrip():
+    for pauli in Pauli:
+        assert Pauli._from_rs(pauli._to_rs()) == pauli
+
+    for pauli in tket2._tket2.ops.Pauli.values():
+        assert Pauli._from_rs(pauli)._to_rs() == pauli

tket2-py/tket2/_tket2/circuit.pyi

@@ -1,6 +1,7 @@
-from enum import Enum, auto
+from enum import Enum
 from typing import Any, Callable
 from pytket._tket.circuit import Circuit
+from tket2._tket2.ops import Tk2Op
 
 class Tk2Circuit:
     """Rust representation of a TKET2 circuit."""
@@ -116,31 +117,6 @@ class CircuitCost:
 
         The cost object must implement __add__, __sub__, __eq__, and __lt__."""
 
-class Tk2Op(Enum):
-    """A Tket2 built-in operation."""
-
-    H = auto()
-    CX = auto()
-    T = auto()
-    S = auto()
-    X = auto()
-    Y = auto()
-    Z = auto()
-    Tdg = auto()
-    Sdg = auto()
-    ZZMax = auto()
-    Measure = auto()
-    RzF64 = auto()
-    RxF64 = auto()
-    PhasedX = auto()
-    ZZPhase = auto()
-    AngleAdd = auto()
-    CZ = auto()
-    TK1 = auto()
-    QAlloc = auto()
-    QFree = auto()
-    Reset = auto()
-
 class CustomOp:
     """A HUGR custom operation."""
 
@@ -177,14 +153,6 @@ class HugrType:
     def bool() -> HugrType:
         """Boolean type (HUGR 2-ary unit sum)."""
 
-class Pauli(Enum):
-    """Simple enum representation of Pauli matrices."""
-
-    I = auto()  # noqa: E741
-    X = auto()
-    Y = auto()
-    Z = auto()
-
 class TypeBound(Enum):
     """HUGR type bounds."""