feat(parser): parse function param defaults and sinks

gen/python.py

@@ -44,7 +44,9 @@ class Function:
     name: str
     posonlyargs: list[Argument]
     args: list[Argument]
+    sink: Optional[Argument]
     kwonlyargs: list[Argument]
+    kw_sink: Optional[Argument]
     returns: Optional[MidasType]
     body: list[Stmt]
 
@@ -53,6 +55,7 @@ class Function:
         location: Optional[Location] = None
         name: str
         type: Optional[MidasType]
+        default: Optional[Expr]
 
     @property
     def all_args(self) -> list[Argument]:

midas/ast/python.py

@@ -117,7 +117,9 @@ class Function(Stmt):
     name: str
     posonlyargs: list[Argument]
     args: list[Argument]
+    sink: Optional[Argument]
     kwonlyargs: list[Argument]
+    kw_sink: Optional[Argument]
     returns: Optional[MidasType]
     body: list[Stmt]
 
@@ -126,6 +128,7 @@ class Function(Stmt):
         location: Optional[Location] = None
         name: str
         type: Optional[MidasType]
+        default: Optional[Expr]
 
     @property
     def all_args(self) -> list[Argument]:

midas/parser/python.py

@@ -136,14 +136,23 @@ class PythonParser:
                 args=ast.arguments(
                     posonlyargs=posonlyargs,
                     args=args,
+                    vararg=sink,
                     kwonlyargs=kwonlyargs,
+                    kwarg=kw_sink,
+                    defaults=defaults,
+                    kw_defaults=kw_defaults,
                 ),
                 returns=returns,
                 body=raw_body,
             ):
 
-                def parse_args(args_list: list[ast.arg]) -> list[Function.Argument]:
+                def parse_args(
-                    return [self._parse_function_argument(arg) for arg in args_list]
+                    args_list: list[ast.arg], defaults: list[Optional[Expr]]
+                ) -> list[Function.Argument]:
+                    return [
+                        self._parse_function_argument(arg, default)
+                        for arg, default in zip(args_list, defaults)
+                    ]
 
                 body: list[Stmt] = []
                 for stmt in raw_body:
@@ -152,19 +161,49 @@ class PythonParser:
                         body.append(stmts)
                     elif stmts is not None:
                         body.extend(stmts)
+
+                parsed_defaults: list[Optional[Expr]] = [
+                    self.parse_expr(default) for default in defaults
+                ]
+                n_posargs: int = len(posonlyargs)
+                n_args: int = len(args)
+                n_all_posargs = n_posargs + n_args
+                parsed_defaults = [
+                    None,
+                ] * (n_all_posargs - len(defaults)) + parsed_defaults
+
+                posargs_defaults: list[Optional[Expr]] = parsed_defaults[:n_posargs]
+                args_defaults: list[Optional[Expr]] = parsed_defaults[n_posargs:]
+                kwargs_defaults: list[Optional[Expr]] = [
+                    self.parse_expr(default) if default is not None else None
+                    for default in kw_defaults
+                ]
+
                 return Function(
                     location=loc,
                     name=name,
-                    posonlyargs=parse_args(posonlyargs),
+                    posonlyargs=parse_args(posonlyargs, posargs_defaults),
-                    args=parse_args(args),
+                    args=parse_args(args, args_defaults),
-                    kwonlyargs=parse_args(kwonlyargs),
+                    sink=(
+                        self._parse_function_argument(sink, None)
+                        if sink is not None
+                        else None
+                    ),
+                    kwonlyargs=parse_args(kwonlyargs, kwargs_defaults),
+                    kw_sink=(
+                        self._parse_function_argument(kw_sink, None)
+                        if kw_sink is not None
+                        else None
+                    ),
                     returns=self._parse_type(returns) if returns is not None else None,
                     body=body,
                 )
             case _:
                 print(f"Unsupported function definition: {ast.unparse(node)}")
 
-    def _parse_function_argument(self, arg: ast.arg) -> Function.Argument:
+    def _parse_function_argument(
+        self, arg: ast.arg, default: Optional[Expr]
+    ) -> Function.Argument:
         loc: Location = Location.from_ast(arg)
         name: str = arg.arg
         type: Optional[MidasType] = None
@@ -174,6 +213,7 @@ class PythonParser:
             location=loc,
             name=name,
             type=type,
+            default=default,
         )
 
     def _parse_type(