gh-104683: clinic.py: refactor Parameter and Function as dataclasses (#106477)

Author: AlexWaygood

Diff for: Tools/clinic/clinic.py

@@ -2439,6 +2439,8 @@ def __repr__(self) -> str:
 ParamDict = dict[str, "Parameter"]
 ReturnConverterType = Callable[..., "CReturnConverter"]
 
+
+@dc.dataclass(repr=False)
 class Function:
     """
     Mutable duck type for inspect.Function.
@@ -2450,49 +2452,34 @@ class Function:
         It will always be true that
             (not docstring) or ((not docstring[0].isspace()) and (docstring.rstrip() == docstring))
     """
+    parameters: ParamDict = dc.field(default_factory=dict)
+    _: dc.KW_ONLY
+    name: str
+    module: Module
+    cls: Class | None = None
+    c_basename: str | None = None
+    full_name: str | None = None
+    return_converter: CReturnConverter
+    return_annotation: object = inspect.Signature.empty
+    docstring: str = ''
+    kind: str = CALLABLE
+    coexist: bool = False
+    # docstring_only means "don't generate a machine-readable
+    # signature, just a normal docstring".  it's True for
+    # functions with optional groups because we can't represent
+    # those accurately with inspect.Signature in 3.4.
+    docstring_only: bool = False
 
-    def __init__(
-            self,
-            parameters: ParamDict | None = None,
-            *,
-            name: str,
-            module: Module,
-            cls: Class | None = None,
-            c_basename: str | None = None,
-            full_name: str | None = None,
-            return_converter: CReturnConverter,
-            return_annotation = inspect.Signature.empty,
-            docstring: str | None = None,
-            kind: str = CALLABLE,
-            coexist: bool = False,
-            docstring_only: bool = False
-    ) -> None:
-        self.parameters = parameters or {}
-        self.return_annotation = return_annotation
-        self.name = name
-        self.full_name = full_name
-        self.module = module
-        self.cls = cls
-        self.parent = cls or module
-        self.c_basename = c_basename
-        self.return_converter = return_converter
-        self.docstring = docstring or ''
-        self.kind = kind
-        self.coexist = coexist
+    def __post_init__(self) -> None:
+        self.parent: Class | Module = self.cls or self.module
         self.self_converter: self_converter | None = None
-        # docstring_only means "don't generate a machine-readable
-        # signature, just a normal docstring".  it's True for
-        # functions with optional groups because we can't represent
-        # those accurately with inspect.Signature in 3.4.
-        self.docstring_only = docstring_only
-
-        self.rendered_parameters = None
+        self.__render_parameters__: list[Parameter] | None = None
 
-    __render_parameters__ = None
     @property
-    def render_parameters(self):
+    def render_parameters(self) -> list[Parameter]:
         if not self.__render_parameters__:
-            self.__render_parameters__ = l = []
+            l: list[Parameter] = []
+            self.__render_parameters__ = l
             for p in self.parameters.values():
                 p = p.copy()
                 p.converter.pre_render()
@@ -2517,49 +2504,30 @@ def methoddef_flags(self) -> str | None:
     def __repr__(self) -> str:
         return '<clinic.Function ' + self.name + '>'
 
-    def copy(self, **overrides) -> "Function":
-        kwargs = {
-            'name': self.name, 'module': self.module, 'parameters': self.parameters,
-            'cls': self.cls, 'c_basename': self.c_basename,
-            'full_name': self.full_name,
-            'return_converter': self.return_converter, 'return_annotation': self.return_annotation,
-            'docstring': self.docstring, 'kind': self.kind, 'coexist': self.coexist,
-            'docstring_only': self.docstring_only,
-            }
-        kwargs.update(overrides)
-        f = Function(**kwargs)
+    def copy(self, **overrides: Any) -> Function:
+        f = dc.replace(self, **overrides)
         f.parameters = {
             name: value.copy(function=f)
             for name, value in f.parameters.items()
         }
         return f
 
 
+@dc.dataclass(repr=False, slots=True)
 class Parameter:
     """
     Mutable duck type of inspect.Parameter.
     """
-
-    def __init__(
-            self,
-            name: str,
-            kind: inspect._ParameterKind,
-            *,
-            default = inspect.Parameter.empty,
-            function: Function,
-            converter: "CConverter",
-            annotation = inspect.Parameter.empty,
-            docstring: str | None = None,
-            group: int = 0
-    ) -> None:
-        self.name = name
-        self.kind = kind
-        self.default = default
-        self.function = function
-        self.converter = converter
-        self.annotation = annotation
-        self.docstring = docstring or ''
-        self.group = group
+    name: str
+    kind: inspect._ParameterKind
+    _: dc.KW_ONLY
+    default: object = inspect.Parameter.empty
+    function: Function
+    converter: CConverter
+    annotation: object = inspect.Parameter.empty
+    docstring: str = ''
+    group: int = 0
+    right_bracket_count: int = dc.field(init=False, default=0)
 
     def __repr__(self) -> str:
         return '<clinic.Parameter ' + self.name + '>'
@@ -2576,18 +2544,19 @@ def is_vararg(self) -> bool:
     def is_optional(self) -> bool:
         return not self.is_vararg() and (self.default is not unspecified)
 
-    def copy(self, **overrides) -> "Parameter":
-        kwargs = {
-            'name': self.name, 'kind': self.kind, 'default':self.default,
-                 'function': self.function, 'converter': self.converter, 'annotation': self.annotation,
-                 'docstring': self.docstring, 'group': self.group,
-            }
-        kwargs.update(overrides)
-        if 'converter' not in overrides:
+    def copy(
+        self,
+        /,
+        *,
+        converter: CConverter | None = None,
+        function: Function | None = None,
+        **overrides: Any
+    ) -> Parameter:
+        function = function or self.function
+        if not converter:
             converter = copy.copy(self.converter)
-            converter.function = kwargs['function']
-            kwargs['converter'] = converter
-        return Parameter(**kwargs)
+            converter.function = function
+        return dc.replace(self, **overrides, function=function, converter=converter)
 
     def get_displayname(self, i: int) -> str:
         if i == 0:
@@ -2761,7 +2730,7 @@ def __init__(self,
              # Positional args:
              name: str,
              py_name: str,
-             function,
+             function: Function,
              default: object = unspecified,
              *,  # Keyword only args:
              c_default: str | None = None,
@@ -2800,7 +2769,9 @@ def __init__(self,
         # about the function in the init.
         # (that breaks if we get cloned.)
         # so after this change we will noisily fail.
-        self.function = LandMine("Don't access members of self.function inside converter_init!")
+        self.function: Function | LandMine = LandMine(
+            "Don't access members of self.function inside converter_init!"
+        )
         self.converter_init(**kwargs)
         self.function = function
 
@@ -2810,7 +2781,7 @@ def converter_init(self):
     def is_optional(self) -> bool:
         return (self.default is not unspecified)
 
-    def _render_self(self, parameter: str, data: CRenderData) -> None:
+    def _render_self(self, parameter: Parameter, data: CRenderData) -> None:
         self.parameter = parameter
         name = self.parser_name
 
@@ -2870,7 +2841,7 @@ def _render_non_self(self, parameter, data):
         if cleanup:
             data.cleanup.append('/* Cleanup for ' + name + ' */\n' + cleanup.rstrip() + "\n")
 
-    def render(self, parameter: str, data: CRenderData) -> None:
+    def render(self, parameter: Parameter, data: CRenderData) -> None:
         """
         parameter is a clinic.Parameter instance.
         data is a CRenderData instance.
@@ -5246,7 +5217,7 @@ def format_docstring(self):
         assert isinstance(parameters[0].converter, self_converter)
         # self is always positional-only.
         assert parameters[0].is_positional_only()
-        parameters[0].right_bracket_count = 0
+        assert parameters[0].right_bracket_count == 0
         positional_only = True
         for p in parameters[1:]:
             if not p.is_positional_only():