def foreach(self, fn: Any):
        """Apply a function to each element of the array.

        Args:
            fn: The function to apply.

        Returns:
            The array after applying the function.

        Raises:
            VarTypeError: If the function takes more than one argument.
        """
        from .function import ArgsFunctionOperation

        if not callable(fn):
            raise_unsupported_operand_types("foreach", (type(self), type(fn)))
        # get the number of arguments of the function
        num_args = len(inspect.signature(fn).parameters)
        if num_args > 1:
            msg = "The function passed to foreach should take at most one argument."
            raise VarTypeError(msg)

        if num_args == 0:
            return_value = fn()
            function_var = ArgsFunctionOperation.create((), return_value)
        else:
            # generic number var
            number_var = Var("").to(NumberVar, int)

            first_arg_type = self[number_var]._var_type

            arg_name = get_unique_variable_name()

            # get first argument type
            first_arg = Var(
                _js_expr=arg_name,
                _var_type=first_arg_type,
            ).guess_type()

            function_var = ArgsFunctionOperation.create(
                (arg_name,),
                Var.create(fn(first_arg)),
            )

        return map_array_operation(self, function_var)
Apply a function to each element of the array.

        Args:
            fn: The function to apply.

        Returns:
            The array after applying the function.

        Raises:
            VarTypeError: If the function takes more than one argument.
        
reflex/vars/sequence.py