Add IR to Jet (#11)

* add ir

* move tests

* run black

* add requirements

* update black command

* update changelog

* rename IR to XIR

* update changelog (again)

* run isort

* run isort (again)

* update docstrings

* Apply suggestions from code review

Co-authored-by: Josh Izaac <[email protected]>
Co-authored-by: Mikhail Andrenkov <[email protected]>

Co-authored-by: Josh Izaac <[email protected]>
Co-authored-by: Mikhail Andrenkov <[email protected]>

.github/CHANGELOG.md

@@ -10,6 +10,8 @@
 
 * Running CMake with `-DBUILD_PYTHON=ON` now generates Python bindings within a `jet` package. [(#1)](https://github.com/XanaduAI/jet/pull/1)
 
+* A new intermediate representation (IR) is added, including a parser, IR representation program, and a Strawberry Fields interface. [(#11)](https://github.com/XanaduAI/jet/pull/11)
+
 ### Improvements
 
 * Exceptions are now favoured in place of `std::terminate` with `Exception` being the new base type for all exceptions thrown by Jet. [(#3)](https://github.com/XanaduAI/jet/pull/3)
@@ -32,7 +34,7 @@
 
 This release contains contributions from (in alphabetical order):
 
-[Mikhail Andrenkov](https://github.com/Mandrenkov), [Jack Brown](https://github.com/brownj85), [Lee J. O'Riordan](https://github.com/mlxd), [Trevor Vincent](https://github.com/trevor-vincent).
+[Mikhail Andrenkov](https://github.com/Mandrenkov), [Jack Brown](https://github.com/brownj85), [Theodor Isacsson](https://github.com/thisac), [Lee J. O'Riordan](https://github.com/mlxd), [Trevor Vincent](https://github.com/trevor-vincent).
 
 ## Release 0.1.0 (current release)
 

python/Makefile

@@ -28,9 +28,9 @@ setup: $(.VENV_DIR)/requirements_test.txt.touch
 .PHONY: format
 format:
 ifdef check
-	$(.VENV_BIN)/black --check tests && $(.VENV_BIN)/isort --profile black --check-only tests
+	$(.VENV_BIN)/black -l 100 --check tests && $(.VENV_BIN)/isort --profile black --check-only tests
 else
-	$(.VENV_BIN)/black tests && $(.VENV_BIN)/isort --profile black tests
+	$(.VENV_BIN)/black -l 100 tests && $(.VENV_BIN)/isort --profile black tests
 endif
 
 .PHONY: test

python/requirements_test.txt

@@ -1,3 +1,5 @@
 black
 isort>5
+lark
 pytest>=5,<6
+strawberryfields

python/tests/test_tensor_network_io.py

@@ -4,9 +4,7 @@
 import pytest
 
 
-@pytest.mark.parametrize(
-    "TensorNetworkFile", [jet.TensorNetworkFile32, jet.TensorNetworkFile64]
-)
+@pytest.mark.parametrize("TensorNetworkFile", [jet.TensorNetworkFile32, jet.TensorNetworkFile64])
 def test_tensor_network_file(TensorNetworkFile):
     """Tests that a tensor network file can be constructed."""
     tnf = TensorNetworkFile()

python/tests/xir/test_integration.py

@@ -0,0 +1,93 @@
+# Copyright 2021 Xanadu Quantum Technologies Inc.
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Integration tests for the IR"""
+
+import pytest
+
+from xir import XIRTransformer, xir_parser
+from xir.program import XIRProgram
+from xir.utils import is_equal
+
+
+def parse_script(circuit: str) -> XIRProgram:
+    """Parse and transform a circuit XIR script and return an XIRProgram"""
+    tree = xir_parser.parse(circuit)
+    return XIRTransformer().transform(tree)
+
+
+photonics_script = """
+gate Sgate, 2, 1;
+gate BSgate, 2, 2;
+gate Rgate, 1, 1;
+output MeasureHomodyne;
+
+Sgate(0.7, 0) | [1];
+BSgate(0.1, 0.0) | [0, 1];
+Rgate(0.2) | [1];
+
+MeasureHomodyne(phi: 3) | [0];
+"""
+
+photonics_script_no_decl = """
+use xstd;
+
+Sgate(0.7, 0) | [1];
+BSgate(0.1, 0.0) | [0, 1];
+Rgate(0.2) | [1];
+
+MeasureHomodyne(phi: 3) | [0];
+"""
+
+qubit_script = """
+// this file works with the current parser
+use xstd;
+
+gate h(a)[0, 1]:
+    rz(-2.3932854391951004) | [0];
+    rz(a) | [1];
+    // rz(pi / sin(3 * 4 / 2 - 2)) | [a, 2];
+end;
+
+operator o(a):
+    0.7 * sin(a), X[0] @ Z[1];
+    -1.6, X[0];
+    2.45, Y[0] @ X[1];
+end;
+
+g_one(pi) | [0, 1];
+g_two | [2];
+g_three(1, 3.3) | [2];
+
+// The circuit and statistics
+ry(1.23) | [0];
+rot(0.1, 0.2, 0.3) | [1];
+h(0.2) | [0, 1, 2];
+
+sample(observable: o(0.2), shots: 1000) | [0, 1];
+"""
+
+
+class TestParser:
+    """Integration tests for parsing, and serializing, XIR scripts"""
+
+    @pytest.mark.parametrize("circuit", [qubit_script, photonics_script, photonics_script_no_decl])
+    def test_parse_and_serialize(self, circuit):
+        """Test parsing and serializing an XIR script.
+
+        Tests parsing, serializing as well as the ``is_equal`` utils function.
+        """
+        irprog = parse_script(circuit)
+        res = irprog.serialize()
+        assert is_equal(res, circuit)

python/tests/xir/test_io.py

@@ -0,0 +1,193 @@
+# Copyright 2021 Xanadu Quantum Technologies Inc.
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tests for the interfaces module"""
+
+from decimal import Decimal
+from typing import List, Tuple
+
+import pytest
+import strawberryfields as sf
+from strawberryfields import ops
+
+from xir.interfaces.strawberryfields_io import to_program, to_xir
+from xir.program import GateDeclaration, Statement, XIRProgram
+
+
+def create_xir_prog(
+    data: List[Tuple],
+    external_libs: List[str] = None,
+    include_decl: bool = True,
+    version: str = None,
+) -> XIRProgram:
+    """Create an XIRProgram object used for testing"""
+    # if no version number is passed, use the default one (by not specifying it)
+    if version is None:
+        irprog = XIRProgram()
+    else:
+        irprog = XIRProgram(version=version)
+
+    # add the statements to the program
+    stmts = [Statement(n, p, w) for n, p, w in data]
+    irprog._statements.extend(stmts)
+
+    # if declaration should be included, add them to the program
+    if include_decl:
+        declarations = [GateDeclaration(n, len(p), len(w)) for n, p, w in data]
+        irprog._declarations["gate"].extend(declarations)
+
+    # if any external libraries/files are included, add them to the program
+    if external_libs is not None:
+        irprog._include.extend(external_libs)
+
+    return irprog
+
+
+def create_sf_prog(num_of_wires: int, ops: List[Tuple]):
+    """Create a Strawberry Fields program"""
+    prog = sf.Program(num_of_wires)
+
+    with prog.context as q:
+        for gate, params, wires in ops:
+            regrefs = [q[w] for w in wires]
+            if len(params) == 0:
+                gate | regrefs
+            else:
+                gate(*params) | regrefs
+
+    return prog
+
+
+class TestXIRToStrawberryFields:
+    """Unit tests for the XIR to Strawberry Fields conversion"""
+
+    def test_empty_irprogram(self):
+        """Test that converting an empty XIR program raises an error"""
+        irprog = create_xir_prog(data=[])
+        with pytest.raises(ValueError, match="XIR program is empty and cannot be transformed"):
+            to_program(irprog)
+
+    def test_gate_not_defined(self):
+        """Test unknown gate raises error"""
+        circuit_data = [
+            ("not_a_real_gate", [Decimal("0.42")], (1, 2, 3)),
+        ]
+        irprog = create_xir_prog(data=circuit_data)
+
+        with pytest.raises(NameError, match="operation 'not_a_real_gate' not defined"):
+            to_program(irprog)
+
+    def test_gates_no_args(self):
+        """Test that gates without arguments work"""
+        circuit_data = [
+            ("Vac", [], (0,)),
+        ]
+        irprog = create_xir_prog(data=circuit_data)
+
+        sfprog = to_program(irprog)
+
+        assert len(sfprog) == 1
+        assert sfprog.circuit[0].op.__class__.__name__ == "Vacuum"
+        assert sfprog.circuit[0].reg[0].ind == 0
+
+    def test_gates_with_args(self):
+        """Test that gates with arguments work"""
+
+        circuit_data = [
+            ("Sgate", [Decimal("0.1"), Decimal("0.2")], (0,)),
+            ("Sgate", [Decimal("0.3")], (1,)),
+        ]
+        irprog = create_xir_prog(data=circuit_data)
+        sfprog = to_program(irprog)
+
+        assert len(sfprog) == 2
+        assert sfprog.circuit[0].op.__class__.__name__ == "Sgate"
+        assert sfprog.circuit[0].op.p[0] == 0.1
+        assert sfprog.circuit[0].op.p[1] == 0.2
+        assert sfprog.circuit[0].reg[0].ind == 0
+
+        assert sfprog.circuit[1].op.__class__.__name__ == "Sgate"
+        assert sfprog.circuit[1].op.p[0] == 0.3
+        assert sfprog.circuit[1].op.p[1] == 0.0  # default value
+        assert sfprog.circuit[1].reg[0].ind == 1
+
+
+class TestStrawberryFieldsToXIR:
+    """Unit tests for the XIR to Strawberry Fields conversion"""
+
+    def test_empty_sfprogram(self):
+        """Test that converting from an empty SF program works"""
+        sfprog = create_sf_prog(num_of_wires=2, ops=[])
+        irprog = to_xir(sfprog)
+
+        assert irprog.version == "0.1.0"
+        assert irprog.statements == []
+        assert irprog.include == []
+        assert irprog.statements == []
+        assert irprog.declarations == {"gate": [], "func": [], "output": [], "operator": []}
+
+        assert irprog.gates == dict()
+        assert irprog.operators == dict()
+        assert irprog.variables == set()
+        assert irprog._called_ops == set()
+
+    @pytest.mark.parametrize("add_decl", [True, False])
+    def test_gates_no_args(self, add_decl):
+        """Test unknown gate raises error"""
+        circuit_data = [
+            (ops.Vac, [], (0,)),
+        ]
+
+        sfprog = create_sf_prog(num_of_wires=2, ops=circuit_data)
+        irprog = to_xir(sfprog, add_decl=add_decl)
+
+        assert irprog.statements[0].name == "Vacuum"
+        assert irprog.statements[0].params == []
+        assert irprog.statements[0].wires == (0,)
+
+        if add_decl:
+            assert len(irprog.declarations["gate"]) == 1
+            assert irprog.declarations["gate"][0].name == "Vacuum"
+            assert irprog.declarations["gate"][0].num_params == 0
+            assert irprog.declarations["gate"][0].num_wires == 1
+        else:
+            assert irprog.declarations["gate"] == []
+
+    @pytest.mark.parametrize("add_decl", [True, False])
+    def test_gates_with_args(self, add_decl):
+        """Test that gates with arguments work"""
+
+        circuit_data = [
+            (ops.Sgate, [0.1, 0.2], (0,)),
+            (ops.Sgate, [Decimal("0.3")], (1,)),
+        ]
+
+        sfprog = create_sf_prog(num_of_wires=2, ops=circuit_data)
+        irprog = to_xir(sfprog, add_decl=add_decl)
+
+        assert irprog.statements[0].name == "Sgate"
+        assert irprog.statements[0].params == [0.1, 0.2]
+        assert irprog.statements[0].wires == (0,)
+
+        assert irprog.statements[1].name == "Sgate"
+        assert irprog.statements[1].params == [Decimal("0.3"), 0.0]
+        assert irprog.statements[1].wires == (1,)
+
+        if add_decl:
+            assert len(irprog.declarations["gate"]) == 1
+            assert irprog.declarations["gate"][0].name == "Sgate"
+            assert irprog.declarations["gate"][0].num_params == 2
+            assert irprog.declarations["gate"][0].num_wires == 1
+        else:
+            assert irprog.declarations["gate"] == []