Class ArgUseFinder

mypy/suggestions.py:164–194

Visitor for finding all the types of arguments that each arg is passed to. This is extremely simple minded but might be effective anyways.

class ArgUseFinder(TraverserVisitor):
    """Visitor for finding all the types of arguments that each arg is passed to.

    This is extremely simple minded but might be effective anyways.
    """

    def __init__(self, func: FuncDef, typemap: dict[Expression, Type]) -> None:
        self.typemap = typemap
        self.arg_types: dict[SymbolNode, list[Type]] = {arg.variable: [] for arg in func.arguments}

    def visit_call_expr(self, o: CallExpr) -> None:
        if not any(isinstance(e, RefExpr) and e.node in self.arg_types for e in o.args):
            return

        typ = get_proper_type(self.typemap.get(o.callee))
        if not isinstance(typ, CallableType):
            return

        formal_to_actual = map_actuals_to_formals(
            o.arg_kinds,
            o.arg_names,
            typ.arg_kinds,
            typ.arg_names,
            lambda n: AnyType(TypeOfAny.special_form),
        )

        for i, args in enumerate(formal_to_actual):
            for arg_idx in args:
                arg = o.args[arg_idx]
                if isinstance(arg, RefExpr) and arg.node in self.arg_types:
                    self.arg_types[arg.node].append(typ.arg_types[i])


def get_arg_uses(typemap: dict[Expression, Type], func: FuncDef) -> list[list[Type]]: