Merge pull request #101 from ColibrITD-SAS/feat-custom-basis

Feat custom basis

Author: Henri-ColibrITD

mpqp/core/circuit.py

@@ -31,3 +31,9 @@ def to_other_language(
             from qiskit.circuit.library import Barrier as QiskitBarrier
 
             return QiskitBarrier(self.size)
+        elif language == Language.QASM2:
+            qubits = ",".join([f"q[{j}]" for j in self.targets])
+            return "barrier " + qubits + ";"
+
+    def __repr__(self):
+        return f"{type(self).__name__}({self.size})"

mpqp/core/instruction/barrier.py

@@ -1,6 +1,10 @@
 from __future__ import annotations
+from typing import Optional
+
+from qiskit.circuit import Parameter
 
 from mpqp.core.instruction import Instruction
+from mpqp.core.languages import Language
 
 
 class Breakpoint(Instruction):
@@ -30,3 +34,10 @@ def __repr__(self) -> str:
             f"Breakpoint(targets={self.targets}, draw_circuit={self.draw_circuit},"
             f" enabled={self.enabled}, label={self.label})"
         )
+
+    def to_other_language(
+        self,
+        language: Language = Language.QISKIT,
+        qiskit_parameters: Optional[set["Parameter"]] = None,
+    ) -> str:
+        raise NotImplementedError(f"Error: {language} is not supported")

mpqp/core/instruction/breakpoint.py

@@ -83,11 +83,49 @@ def to_other_language(
         language: Language = Language.QISKIT,
         qiskit_parameters: Optional[set["Parameter"]] = None,
     ):
-        from qiskit.quantum_info.operators import Operator as QiskitOperator
+        if language == Language.QISKIT:
+            from qiskit.quantum_info.operators import Operator as QiskitOperator
+
+            if qiskit_parameters is None:
+                qiskit_parameters = set()
+            return QiskitOperator(self.matrix)
+        elif language == Language.QASM2:
+            from mpqp.tools.circuit import replace_custom_gate
+            from qiskit import QuantumCircuit, qasm2
+
+            nb_qubits = max(self.targets) + 1
+
+            qiskit_circ = QuantumCircuit(nb_qubits)
+            instr = self.to_other_language(Language.QISKIT)
+            if TYPE_CHECKING:
+                from qiskit.quantum_info.operators import Operator as QiskitOperator
+
+                assert isinstance(instr, QiskitOperator)
+            qiskit_circ.unitary(
+                instr,
+                list(reversed(self.targets)),  # dang qiskit qubits order
+                self.label,
+            )
 
-        if qiskit_parameters is None:
-            qiskit_parameters = set()
-        return QiskitOperator(self.matrix)
+            circuit, gphase = replace_custom_gate(qiskit_circ.data[0], nb_qubits)
+
+            qasm_str = qasm2.dumps(circuit)
+            qasm_lines = qasm_str.splitlines()
+
+            instructions_only = [
+                line
+                for line in qasm_lines
+                if not (
+                    line.startswith("qreg")
+                    or line.startswith("include")
+                    or line.startswith("creg")
+                    or line.startswith("OPENQASM")
+                )
+            ]
+
+            return "\n".join(instructions_only), gphase
+        else:
+            raise NotImplementedError(f"Error: {language} is not supported")
 
     def __repr__(self) -> str:
         label = ", " + self.label if self.label else ""