feat: add measure_array and discard_array quantum function (#710)

Co-authored-by: Mark Koch <[email protected]>

guppylang/std/quantum.py

@@ -13,7 +13,7 @@
 )
 from guppylang.std._internal.util import quantum_op
 from guppylang.std.angles import angle
-from guppylang.std.builtins import owned
+from guppylang.std.builtins import array, owned
 from guppylang.std.option import Option
 
 
@@ -144,3 +144,21 @@ def measure(q: qubit @ owned) -> bool: ...
 @guppy.hugr_op(quantum_op("Reset"))
 @no_type_check
 def reset(q: qubit) -> None: ...
+
+
+N = guppy.nat_var("N")
+
+
+@guppy
+@no_type_check
+def measure_array(qubits: array[qubit, N] @ owned) -> array[bool, N]:
+    """Measure an array of qubits, returning an array of bools."""
+    return array(measure(q) for q in qubits)
+
+
+@guppy
+@no_type_check
+def discard_array(qubits: array[qubit, N] @ owned) -> None:
+    """Discard an array of qubits."""
+    for q in qubits:
+        discard(q)

tests/integration/test_quantum.py

@@ -6,9 +6,16 @@
 from guppylang.module import GuppyModule
 from guppylang.std.angles import angle
 
-from guppylang.std.builtins import owned
-
-from guppylang.std.quantum import discard, measure, qubit, maybe_qubit
+from guppylang.std.builtins import owned, array
+
+from guppylang.std.quantum import (
+    discard,
+    measure,
+    qubit,
+    maybe_qubit,
+    measure_array,
+    discard_array,
+)
 from guppylang.std.quantum_functional import (
     cx,
     cy,
@@ -43,7 +50,9 @@ def compile_quantum_guppy(fn) -> ModulePointer:
     ), "`@compile_quantum_guppy` does not support extra arguments."
 
     module = GuppyModule("module")
-    module.load(angle, qubit, discard, measure, maybe_qubit)
+    module.load(
+        angle, qubit, discard, measure, measure_array, maybe_qubit, discard_array
+    )
     module.load_all(quantum_functional)
     guppylang.decorator.guppy(module)(fn)
     return module.compile()
@@ -123,3 +132,25 @@ def test(
         q2 = rz(q2, a3)
         q1, q2 = crz(q1, q2, a3)
         return (q1, q2)
+
+
+def test_measure_array(validate):
+    """Build and measure array."""
+
+    @compile_quantum_guppy
+    def test() -> array[bool, 10]:
+        qs = array(qubit() for _ in range(10))
+        return measure_array(qs)
+
+    validate(test)
+
+
+def test_discard_array(validate):
+    """Build and discard array."""
+
+    @compile_quantum_guppy
+    def test() -> None:
+        qs = array(qubit() for _ in range(10))
+        discard_array(qs)
+
+    validate(test)