-- Name: all_same_final(anyarray); Type: FUNCTION; Schema: util; Owner: -

--

CREATE FUNCTION all_same_final(state anyarray) RETURNS boolean

    LANGUAGE sql IMMUTABLE

    AS $_$

SELECT $1 IS NULL/*no rows*/ OR util.not_empty($1)/*not no_match_sentinel*/

$_$;

--

-- Name: all_same_transform(anyarray, anyelement); Type: FUNCTION; Schema: util; Owner: -

--

CREATE FUNCTION all_same_transform(state anyarray, value anyelement) RETURNS anyarray

    LANGUAGE plpgsql IMMUTABLE

    AS $$

DECLARE

	value_cmp         state%TYPE = ARRAY[value];

	state             state%TYPE = COALESCE(state, value_cmp);

	no_match_sentinel state%TYPE = value_cmp[1:0]/*=ARRAY[]::state%TYPE*/;

BEGIN

	RETURN (CASE WHEN value_cmp IS NOT DISTINCT FROM state THEN state ELSE no_match_sentinel END);

END;

$$;

--

-- Name: all_same(anyelement); Type: AGGREGATE; Schema: util; Owner: -

--

CREATE AGGREGATE all_same(anyelement) (

    SFUNC = all_same_transform,

    STYPE = anyarray,

    FINALFUNC = all_same_final

);

--

-- Name: AGGREGATE all_same(anyelement); Type: COMMENT; Schema: util; Owner: -

--

COMMENT ON AGGREGATE all_same(anyelement) IS 'includes NULLs in comparison';

--