fix(pickle): make Parameter instances pickleable (#9798)

The pickles expect a specific constructor for `Parameter`, so remove our
custom constructor and provide a `classmethod` with the previous
behavior for convenience. Closes #9793.

ibis/common/annotations.py

@@ -6,6 +6,8 @@
 from typing import TYPE_CHECKING
 from typing import Any as AnyType
 
+from typing_extensions import Self
+
 from ibis.common.bases import Immutable, Slotted
 from ibis.common.patterns import (
     Any,
@@ -258,18 +260,6 @@ class Parameter(inspect.Parameter):
 
     __slots__ = ()
 
-    def __init__(self, name, annotation):
-        if not isinstance(annotation, Argument):
-            raise TypeError(
-                f"annotation must be an instance of Argument, got {annotation}"
-            )
-        super().__init__(
-            name,
-            kind=annotation.kind,
-            default=annotation.default,
-            annotation=annotation,
-        )
-
     def __str__(self):
         formatted = self._name
 
@@ -290,6 +280,20 @@ def __str__(self):
 
         return formatted
 
+    @classmethod
+    def from_argument(cls, name: str, annotation: Argument) -> Self:
+        """Construct a Parameter from an Argument annotation."""
+        if not isinstance(annotation, Argument):
+            raise TypeError(
+                f"annotation must be an instance of Argument, got {annotation}"
+            )
+        return cls(
+            name,
+            kind=annotation.kind,
+            default=annotation.default,
+            annotation=annotation,
+        )
+
 
 class Signature(inspect.Signature):
     """Validatable signature.
@@ -324,7 +328,7 @@ def merge(cls, *signatures, **annotations):
 
         inherited = set(params.keys())
         for name, annot in annotations.items():
-            params[name] = Parameter(name, annotation=annot)
+            params[name] = Parameter.from_argument(name, annotation=annot)
 
         # mandatory fields without default values must precede the optional
         # ones in the function signature, the partial ordering will be kept
@@ -406,7 +410,7 @@ def from_callable(cls, fn, patterns=None, return_pattern=None):
             else:
                 annot = Argument(pattern, kind=kind, default=default, typehint=typehint)
 
-            parameters.append(Parameter(param.name, annot))
+            parameters.append(Parameter.from_argument(param.name, annot))
 
         if return_pattern is not None:
             return_annotation = return_pattern

ibis/common/tests/test_annotations.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import inspect
+import pickle
 from typing import Annotated, Union
 
 import pytest
@@ -140,20 +141,20 @@ def fn(x, this):
         return int(x) + this["other"]
 
     annot = argument(fn)
-    p = Parameter("test", annotation=annot)
+    p = Parameter.from_argument("test", annotation=annot)
 
     assert p.annotation is annot
     assert p.default is inspect.Parameter.empty
     assert p.annotation.pattern.match("2", {"other": 1}) == 3
 
     ofn = optional(fn)
-    op = Parameter("test", annotation=ofn)
+    op = Parameter.from_argument("test", annotation=ofn)
     assert op.annotation.pattern == Option(fn, default=None)
     assert op.default is None
     assert op.annotation.pattern.match(None, {"other": 1}) is None
 
     with pytest.raises(TypeError, match="annotation must be an instance of Argument"):
-        Parameter("wrong", annotation=Attribute(lambda x, context: x))
+        Parameter.from_argument("wrong", annotation=Attribute(lambda x, context: x))
 
 
 def test_signature():
@@ -163,8 +164,8 @@ def to_int(x, this):
     def add_other(x, this):
         return int(x) + this["other"]
 
-    other = Parameter("other", annotation=Argument(to_int))
-    this = Parameter("this", annotation=Argument(add_other))
+    other = Parameter.from_argument("other", annotation=Argument(to_int))
+    this = Parameter.from_argument("this", annotation=Argument(add_other))
 
     sig = Signature(parameters=[other, this])
     assert sig.validate(None, args=(1, 2), kwargs={}) == {"other": 1, "this": 3}
@@ -275,8 +276,8 @@ def to_int(x, this):
     def add_other(x, this):
         return int(x) + this["other"]
 
-    other = Parameter("other", annotation=Argument(to_int))
-    this = Parameter("this", annotation=Argument(add_other))
+    other = Parameter.from_argument("other", annotation=Argument(to_int))
+    this = Parameter.from_argument("this", annotation=Argument(add_other))
 
     sig = Signature(parameters=[other, this])
     params = sig.validate(None, args=(1,), kwargs=dict(this=2))
@@ -286,14 +287,16 @@ def add_other(x, this):
     assert kwargs == {}
 
 
-a = Parameter("a", annotation=Argument(CoercedTo(float)))
-b = Parameter("b", annotation=Argument(CoercedTo(float)))
-c = Parameter("c", annotation=Argument(CoercedTo(float), default=0))
-d = Parameter(
+a = Parameter.from_argument("a", annotation=Argument(CoercedTo(float)))
+b = Parameter.from_argument("b", annotation=Argument(CoercedTo(float)))
+c = Parameter.from_argument("c", annotation=Argument(CoercedTo(float), default=0))
+d = Parameter.from_argument(
     "d",
     annotation=Argument(TupleOf(CoercedTo(float)), default=()),
 )
-e = Parameter("e", annotation=Argument(Option(CoercedTo(float)), default=None))
+e = Parameter.from_argument(
+    "e", annotation=Argument(Option(CoercedTo(float)), default=None)
+)
 sig = Signature(parameters=[a, b, c, d, e])
 
 
@@ -480,3 +483,14 @@ def test(a: float, b: float, *args: int, **kwargs: int): ...
         test(1.0, 2.0, 3.0, 4, c=5.0, d=6)
 
     assert len(excinfo.value.errors) == 2
+
+
+def test_pickle():
+    a = Parameter.from_argument("a", annotation=Argument(int))
+    assert pickle.loads(pickle.dumps(a)) == a
+
+
+def test_cloudpickle():
+    cloudpickle = pytest.importorskip("cloudpickle")
+    a = Parameter.from_argument("a", annotation=Argument(int))
+    assert cloudpickle.loads(cloudpickle.dumps(a)) == a

ibis/common/tests/test_grounds.py

@@ -449,33 +449,41 @@ class IntAddClip(FloatAddClip, IntBinop):
 
     assert IntBinop.__signature__ == Signature(
         [
-            Parameter("left", annotation=Argument(is_int)),
-            Parameter("right", annotation=Argument(is_int)),
+            Parameter.from_argument("left", annotation=Argument(is_int)),
+            Parameter.from_argument("right", annotation=Argument(is_int)),
         ]
     )
 
     assert FloatAddRhs.__signature__ == Signature(
         [
-            Parameter("left", annotation=Argument(is_int)),
-            Parameter("right", annotation=Argument(is_float)),
+            Parameter.from_argument("left", annotation=Argument(is_int)),
+            Parameter.from_argument("right", annotation=Argument(is_float)),
         ]
     )
 
     assert FloatAddClip.__signature__ == Signature(
         [
-            Parameter("left", annotation=Argument(is_float)),
-            Parameter("right", annotation=Argument(is_float)),
-            Parameter("clip_lower", annotation=optional(is_int, default=0)),
-            Parameter("clip_upper", annotation=optional(is_int, default=10)),
+            Parameter.from_argument("left", annotation=Argument(is_float)),
+            Parameter.from_argument("right", annotation=Argument(is_float)),
+            Parameter.from_argument(
+                "clip_lower", annotation=optional(is_int, default=0)
+            ),
+            Parameter.from_argument(
+                "clip_upper", annotation=optional(is_int, default=10)
+            ),
         ]
     )
 
     assert IntAddClip.__signature__ == Signature(
         [
-            Parameter("left", annotation=Argument(is_int)),
-            Parameter("right", annotation=Argument(is_int)),
-            Parameter("clip_lower", annotation=optional(is_int, default=0)),
-            Parameter("clip_upper", annotation=optional(is_int, default=10)),
+            Parameter.from_argument("left", annotation=Argument(is_int)),
+            Parameter.from_argument("right", annotation=Argument(is_int)),
+            Parameter.from_argument(
+                "clip_lower", annotation=optional(is_int, default=0)
+            ),
+            Parameter.from_argument(
+                "clip_upper", annotation=optional(is_int, default=10)
+            ),
         ]
     )
 

pyproject.toml

@@ -105,6 +105,7 @@ ruff = ">=0.1.8"
 tqdm = ">=4.66.1,<5"
 
 [tool.poetry.group.test.dependencies]
+cloudpickle = ">=3,<4"
 filelock = ">=3.7.0,<4"
 hypothesis = ">=6.58.0,<7"
 packaging = ">=21.3,<25"