fix: Respect inverse in scalar binop

.pre-commit-config.yaml

@@ -62,6 +62,7 @@ repos:
  rev: v1.10.0
  hooks:
  - id: mypy
+ files: "src/"
  args: [--ignore-missing-imports]
  additional_dependencies:
  - dask

pyproject.toml

@@ -111,7 +111,8 @@ src_paths = ["src", "tests"]
 
 [tool.mypy]
 python_version = "3.9"
-files = ["src", "tests"]
+files = ["src"]
+exclude = ["tests/"]
 strict = false
 warn_unused_configs = true
 show_error_codes = true

src/dask_awkward/lib/core.py

@@ -502,9 +502,17 @@ def f(self, other):
  if is_dask_collection(other):
  task = (op, self.key, *other.__dask_keys__())
  deps.append(other)
- plns.append(other.name)
+ if inv:
+ plns.insert(0, other.name)
+ else:
+ plns.append(other.name)
  else:
- task = (op, self.key, other)
+ if inv:
+ task = (op, other, self.key)
+ else:
+ task = (op, self.key, other)
+ if inv:
+ plns.reverse()
  graph = HighLevelGraph.from_collections(
  name,
  layer=AwkwardMaterializedLayer(
@@ -514,10 +522,16 @@ def f(self, other):
  ),
  dependencies=tuple(deps),
  )
- if isinstance(other, Scalar):
- meta = op(self._meta, other._meta)
+ if isinstance(other, (Scalar, Array)):
+ if inv:
+ meta = op(other._meta, self._meta)
+ else:
+ meta = op(self._meta, other._meta)
  else:
- meta = op(self._meta, other)
+ if inv:
+ meta = op(other, self._meta)
+ else:
+ meta = op(self._meta, other)
  return new_scalar_object(graph, name, meta=meta)
 
  return f

tests/test_core.py

@@ -115,7 +115,7 @@ def test_len(ndjson_points_file: str) -> None:
  assert len(daa) == 10
  daa.eager_compute_divisions()
  assert daa.known_divisions
- assert len(daa) == 10 # type: ignore
+ assert len(daa) == 10
 
 
 def test_meta_exists(daa: Array) -> None:
@@ -157,7 +157,7 @@ def test_partitions_divisions(ndjson_points_file: str) -> None:
  assert not t1.known_divisions
  t2 = daa.partitions[1]
  assert t2.known_divisions
- assert t2.divisions == (0, divs[2] - divs[1]) # type: ignore
+ assert t2.divisions == (0, divs[2] - divs[1])
 
 
 def test_array_rebuild(ndjson_points_file: str) -> None:
@@ -537,7 +537,7 @@ def test_compatible_partitions_after_slice() -> None:
  assert_eq(lazy, ccrt)
 
  # sanity
- assert dak.compatible_partitions(lazy, lazy + 2) # type: ignore
+ assert dak.compatible_partitions(lazy, lazy + 2)
  assert dak.compatible_partitions(lazy, dak.num(lazy, axis=1) > 2)
 
  assert not dak.compatible_partitions(lazy[:-2], lazy)
@@ -646,6 +646,14 @@ def test_scalar_divisions(daa: Array) -> None:
  assert s.divisions == (None, None)
 
 
+def test_scalar_binop_inv() -> None:
+ # GH #515
+ x = dak.from_lists([[1]])
+ y = x[0] # scalar
+ assert (0 - y) == -1
+ assert (y - 0) == 1
+
+
 def test_array_persist(daa: Array) -> None:
  daa2 = daa["points"]["x"].persist()
  assert_eq(daa["points"]["x"], daa2)
@@ -886,7 +894,7 @@ def test_shape_only_ops(fn: Callable, tmp_path_factory: pytest.TempPathFactory)
  p = tmp_path_factory.mktemp("zeros-like-flat")
  ak.to_parquet(a, str(p / "file.parquet"))
  lazy = dak.from_parquet(str(p))
- result = fn(lazy.b) # type: ignore
+ result = fn(lazy.b)
  with dask.config.set({"awkward.optimization.enabled": True}):
  result.compute()
 
@@ -898,7 +906,7 @@ def test_assign_behavior() -> None:
  with pytest.raises(
  TypeError, match="'mappingproxy' object does not support item assignment"
  ):
- dx.behavior["should_fail"] = None # type: ignore
+ dx.behavior["should_fail"] = None
  assert dx.behavior == behavior
 
 
@@ -909,7 +917,7 @@ def test_assign_attrs() -> None:
  with pytest.raises(
  TypeError, match="'mappingproxy' object does not support item assignment"
  ):
- dx.attrs["should_fail"] = None # type: ignore
+ dx.attrs["should_fail"] = None
  assert dx.attrs == attrs