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);