SQL error - error part position

1.sql-error-position.sql

create table ttt (aaa varchar2(10),bbb varchar2(10));

declare
    cur integer;
    str varchar2(100):='insert into ttt ("no","cols") values ("no such","column here")';
    err_position int; 
begin
    cur := dbms_sql.open_cursor;
    dbms_sql.parse(cur, str,
                   dbms_sql.native);
exception when others then
    err_position:=dbms_sql.last_error_position;
    dbms_output.put_line('Error at #'||err_position);
    dbms_output.put_line(
        substr(str,1,err_position-1)
        ||'>>>'
        ||substr(str,err_position,err_position+1)
        ||'<<<'
        ||substr(str,err_position+2)
    );
    dbms_output.put_line('Error stack:');
    dbms_output.put_line (dbms_utility.format_error_stack);
    dbms_sql.close_cursor(cur);
end;
/

2.output.sql

Error at #48
insert into ttt ("no","cols") values ("no such">>>,"column here")<<<column here")
Error stack:
ORA-00984: column not allowed here
ORA-06512: at "SYS.DBMS_SQL", line 1134