feat(qsystem): add RNG.random_advance()

guppylang/pyproject.toml

@@ -34,9 +34,9 @@ classifiers = [
 
 dependencies = [
     "guppylang-internals ~= 0.24.0",
-    "selene-sim~=0.2.3",
-    "selene-hugr-qis-compiler~=0.2.8",
     "numpy~=2.0",
+    "selene-hugr-qis-compiler~=0.2.8",
+    "selene-sim~=0.2.3",
     "tqdm>=4.67.1",
     "types-tqdm>=4.67.0.20250809",
 ]

guppylang/src/guppylang/std/qsystem/random.py

@@ -73,6 +73,16 @@ def random_int_bounded(self: "RNG", bound: int) -> int:
             bound: The upper bound of the range, needs to less than 2^31.
         """
 
+    @hugr_op(external_op("RandomAdvance", [], ext=QSYSTEM_RANDOM_EXTENSION))
+    @no_type_check
+    def random_advance(self: "RNG", delta: int) -> None:
+        """Advance or backtrack the RNG state by a given number of steps.
+
+        Args:
+            delta: Number of steps to move the RNG state forward (if positive)
+            or backward (if negative).
+        """
+
     @guppy
     @no_type_check
     def shuffle(self: "RNG", array: array[SHUFFLE_T, SHUFFLE_N]) -> None:

pyproject.toml

@@ -32,7 +32,6 @@ miette-py = { workspace = true }
 
 # Uncomment these to test the latest dependency version during development
 # hugr = { git = "https://github.com/CQCL/hugr", subdirectory = "hugr-py", rev = "50a2bac" }
-# tket = { git = "https://github.com/CQCL/tket2", subdirectory = "tket-py", rev = "e704c19" }
 
 [build-system]
 requires = ["hatchling"]

tests/integration/test_qsystem.py

@@ -60,6 +60,24 @@ def test() -> tuple[int, float, int, int, angle, angle]:
     validate(test.compile_function())
 
 
+def test_random_advance(validate, run_int_fn):  # type: ignore[no-untyped-def]
+    """Validate behavior of random_advance from qsystem random extension."""
+
+    @guppy
+    def test() -> int:
+        rng = RNG(42)
+        rint_bnd1 = rng.random_int_bounded(100)
+        rng.random_advance(-1)
+        rint_bnd2 = rng.random_int_bounded(100)
+        same = rint_bnd1 == rint_bnd2
+        rng.discard()
+
+        return int(same)
+
+    validate(test.compile_function())
+    run_int_fn(test, 1)
+
+
 def test_measure_leaked(validate):  # type: ignore[no-untyped-def]
     """Compile the measure_leaked operation."""