ada and pl/sql

[Jason King <jhking@airmail.net>]

I'm a long-term pl/sql developer who would like to have a general 
purpose programming language that works a lot like what I'm used to. 
Hence I've been looking at Ada.
There are (from the pl/sql perspective) three significant differences:
1)  Transparent shifting from pl/sql to sql
     FOR x IN (SELECT user_name FROM all_users ) LOOP
         -- do something
     END LOOP ; -- creates a cursor and x.user_name is valid inside the 

                --loop
2)  pl/sql is very forgiving about doing "automatic" conversions
     x number := "1" + 2; -- assigns 3 to x it doesn't raise an error.
3)  The most commonly used string type is varchar2 with usage examples 
   below:
    v varchar2(50);  -- declare a varchar2, max length 50
    v varchar2(50) := 'short string';  -- assign a value, literal <50
                                       -- does not raise an error.
    v varchar2(10) := '12345678901' ;  -- raises value_error
                                       -- literal > max
declare
    v1 varchar2(10) := 'Hello';
    v2 varchar2(10) := 'World';
    v3 varchar2(30);
begin
    v3 := v1 || ' ' || v2 ; -- || is string concat operator.
                            -- no error here since 'Hello World'
                            -- fits.
    dbms_output.put_line(v3) ; -- prints "Hello World"

Issue 1 is true for all languages so I can just deal with it.
Issue 2 I often code around on the pl/sql as its automatic conversions 
aren't always what I want.
Issue 3 is a killer.
Ada string doesn't work because it raises errors for assignments of 
shorter as well as longer strings.  ada.strings.bounded and 
ada.strings.unbounded are issues because assignment (:=) doesn't work 
for them and concatenation is method not an operator.  As far as I can 
tell I can't overload the assignment operator or the || operator.
Other than creating a new language is there some way to make a 
varchar2-like first-class datatype that has its own operators?