Request for builtin function: Double_quote

Folks,

Given the amount of qoute nesting we do in Postgres, I thought that we need a
function that handles automatic doubling of quotes within strings.   I've
written one in PL/pgSQL (below).  I'd really love to see this turned into a
builtin C function.

-Josh

CREATE FUNCTION double_quote(text) returns text as '
DECLARE bad_string ALIAS for $1;       good_string text;       current_pos INT;       old_pos INT;
BEGIN       IF bad_string IS NULL or bad_string = '''' THEN               RETURN bad_string;       END IF;
good_string:= bad_string;       current_pos :=  STRPOS(good_string, chr(39));       WHILE current_pos > 0 LOOP
    old_pos := current_pos;               good_string := SUBSTR(good_string, 1, (current_pos - 1)) ||
   repeat(chr(39), 2) || SUBSTR(good_string, (current_pos  
+ 1));               current_pos := STRPOS(SUBSTR(good_string, (old_pos + 2)),
chr(39));               IF current_pos > 0 THEN                       current_pos := current_pos + old_pos + 1;
     END IF;       END LOOP; 
RETURN good_string;
END;'
LANGUAGE 'plpgsql'
WITH (ISCACHABLE, ISSTRICT);