From 19978a1234ddd7515e82d5a8a449b65a86f5f9ae Mon Sep 17 00:00:00 2001
From: Jean-Christophe Jaskula <jjaskula@amazon.com>
Date: Fri, 11 Aug 2023 11:44:45 -0400
Subject: [PATCH] Handle cases with generators

---
 oqpy/program.py          | 18 +++++++++++-------
 tests/test_directives.py |  9 +++++++++
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/oqpy/program.py b/oqpy/program.py
index 9323f90..42fd6df 100644
--- a/oqpy/program.py
+++ b/oqpy/program.py
@@ -389,25 +389,29 @@ def delay(
         qubits_or_frames: AstConvertible | Iterable[AstConvertible] | None = None,
     ) -> Program:
         """Apply a delay to a set of qubits or frames."""
-        if isinstance(qubits_or_frames, Iterable) and not any(True for _ in qubits_or_frames):
-            return self
-        elif qubits_or_frames is None:
+        ast_duration = to_ast(self, convert_float_to_duration(time))
+
+        if qubits_or_frames is None:
             ast_qubits_or_frames = []
         else:
             if not isinstance(qubits_or_frames, Iterable):
                 qubits_or_frames = [qubits_or_frames]
+            else:
+                qubits_or_frames = list(qubits_or_frames)
+            if len(qubits_or_frames) == 0:
+                return self
             ast_qubits_or_frames = map_to_ast(self, qubits_or_frames)
-        ast_duration = to_ast(self, convert_float_to_duration(time))
         self._add_statement(ast.DelayInstruction(ast_duration, ast_qubits_or_frames))
         return self
 
     def barrier(self, qubits_or_frames: Iterable[AstConvertible] | None = None) -> Program:
         """Apply a barrier to a set of qubits or frames."""
-        if isinstance(qubits_or_frames, Iterable) and not any(True for _ in qubits_or_frames):
-            return self
-        elif qubits_or_frames is None:
+        if qubits_or_frames is None:
             ast_qubits_or_frames = []
         else:
+            qubits_or_frames = list(qubits_or_frames)
+            if len(qubits_or_frames) == 0:
+                return self
             ast_qubits_or_frames = map_to_ast(self, qubits_or_frames)
         self._add_statement(ast.QuantumBarrier(ast_qubits_or_frames))
         return self
diff --git a/tests/test_directives.py b/tests/test_directives.py
index 08c757e..3c30e44 100644
--- a/tests/test_directives.py
+++ b/tests/test_directives.py
@@ -875,6 +875,13 @@ def test_barrier_delay_arguments():
     prog.delay(3e-7, frame1)
     prog.delay(4e-7, [frame, frame1])
 
+    def frame_generator(frames):
+        for frame in frames:
+            yield frame
+
+    prog.barrier(frame_generator([frame, frame1]))
+    prog.delay(5e-7, frame_generator([frame, frame1]))
+
     expected = textwrap.dedent(
         """
         OPENQASM 3.0;
@@ -886,6 +893,8 @@ def test_barrier_delay_arguments():
         barrier frame0, frame1;
         delay[300.0ns] frame1;
         delay[400.0ns] frame0, frame1;
+        barrier frame0, frame1;
+        delay[500.0ns] frame0, frame1;
         """
     ).strip()