Passing record into Postgres function - sql

Question

I'm trying to create an aggregate function that takes a set of records, does some calculations, and returns a number.
I have gotten the following dummy example to work:
CREATE OR REPLACE FUNCTION dummy_func(text) RETURNS int
AS
$$
DECLARE
rec record;
num int := 0;
BEGIN
FOR rec IN EXECUTE $1
LOOP
IF POSITION('some text' IN rec.known_column_name) = 1
THEN
num := num + 1;
END IF;
END LOOP;
RETURN num;
END;
$$ LANGUAGE PLPGSQL;
If I enter
SELECT dummy_func('select * from some_table');
, it works as expected.
However, I would like to make it so that I can use multiple functions and conditions, such as:
SELECT conditional_col_1, dummy_func_1(*), dummy_func_2(*)
FROM some_table
WHERE conditional_col_2 = 'some val'
GROUP BY 1
How can I rewrite my dummy example into being able to function as so (or use a bunch of UNIONS ALL, etc)?
In response to Hambone
If I have the following logic (counting 'a' or counting 'b' * column something3)
CREATE OR REPLACE FUNCTION count_a(text) RETURNS int
AS
$$
DECLARE
rec record;
num int := 0;
BEGIN
FOR rec IN EXECUTE $1
LOOP
num := num + length(regexp_replace(rec.something1, '[^a]+', '', 'g'));
END LOOP;
RETURN num;
END;
$$ LANGUAGE PLPGSQL;
CREATE OR REPLACE FUNCTION count_e_times_something3(text) RETURNS int
AS
$$
DECLARE
rec record;
num int := 0;
BEGIN
FOR rec IN EXECUTE $1
LOOP
num := num + length(regexp_replace(rec.something1, '[^e]+', '', 'g')) * rec.something3::int;
END LOOP;
RETURN num;
END;
$$ LANGUAGE PLPGSQL;
I currently have to execute them individually,
$=# SELECT count_a('SELECT * FROM MY_TEST WHERE something2 = ''A'' and something1 = ''0''');
-[ RECORD 1 ]
count_a | 0
$=# SELECT count_a('SELECT * FROM MY_TEST WHERE something2 = ''A'' and something3 = ''0''');
-[ RECORD 1 ]
count_a | 2
$=# SELECT count_e_times_something3('SELECT * FROM MY_TEST WHERE something2 = ''A'' and something3 = ''0''');
-[ RECORD 1 ]------------+--
count_e_times_something3 | 0
$=# SELECT count_e_times_something3('SELECT * FROM MY_TEST WHERE something2 = ''A'' and something3 = ''1''');
-[ RECORD 1 ]------------+--
count_e_times_something3 | 7
It would be a lot nicer if I could use the following query (I know I need to define an Aggregate function but I can't find any examples where records are taken in an scalars are returned):
SELECT something2, count_a(*), count_e_times_something3(*) FROM MY_TEST WHERE something3 = '1';
something: 'A'
count_a: 3
count_e_times_something3: 7
something: 'B'
count_a: 3
count_e_times_something3: 2
Both count_a resulting in 3 is a coincidence