从函数返回Varray：PLS-00382：表达式类型错误

Question

在调用现有程序包中的函数时遇到此错误。

包装的代码

CREATE OR REPLACE PACKAGE BODY calc
IS
    FUNCTION emp_details (e_id INTEGER)
        RETURN v_varr
    IS
        CURSOR c_emp IS
            SELECT first_name, last_name, email
              FROM emp_data
             WHERE employee_id = e_id;

        v_val     v_varr;
        err_msg   VARCHAR2 (400);

    BEGIN
        v_val :=
            v_varr (NULL,
                    NULL,
                    NULL
                    );

DBMS_OUTPUT.put_line('Inside function: ');

        FOR c1 IN c_emp
        LOOP
            v_val (1) := c1.first_name;
            v_val (2) := c1.last_name;
            v_val (3) := c1.email;
        END LOOP;

    EXCEPTION
        WHEN OTHERS
        THEN
            err_msg := SUBSTR (SQLERRM, 2, 300);
            DBMS_OUTPUT.put_line ('Error: ' || err_msg);

            RETURN v_val;
    END emp_details;
END calc;

调用时出错。

DECLARE
    TYPE v_vall IS VARRAY (3) OF VARCHAR (50);

    v_call   v_vall;
    err_msg varchar2(100);

BEGIN

    v_call := calc.emp_details (109);

    DBMS_OUTPUT.put_line (v_call (1) || v_call (2) || v_call (3));

    EXCEPTION
        WHEN OTHERS
        THEN
            err_msg := SUBSTR (SQLERRM, 2, 300);
            DBMS_OUTPUT.put_line ('Error: ' || err_msg);
END;

在此行出现错误：

v_call := calc.emp_details (109);