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@DexterHaslem DexterHaslem/life.sql

Last active Mar 9, 2018
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CREATE SCHEMA IF NOT EXISTS life;
SET search_path = life;
CREATE TABLE IF NOT EXISTS life.state (
generation SERIAL PRIMARY KEY NOT NULL,
--size INT NOT NULL CHECK (size >= 3),
state BOOL []
);
CREATE OR REPLACE FUNCTION life.neighbor_alive_count(u BOOL [], x INT, y INT)
RETURNS INT AS $$
DECLARE
ac INT := 0;
BEGIN
FOR xo IN -1..1 LOOP
FOR yo IN -1..1 LOOP
IF xo = 0 AND yo = 0
THEN
-- dont count ourselves as a neighbor
CONTINUE;
END IF;
-- we get off easy here, going out of bounds returns <NULL>
IF u [x + xo] [y + yo]
THEN
ac := ac + 1;
END IF;
END LOOP;
END LOOP;
RETURN ac;
END;
$$ LANGUAGE plpgsql IMMUTABLE STRICT;
CREATE OR REPLACE FUNCTION life.next_cell_state(cur BOOL, alive_nb INT)
RETURNS BOOL AS $$
BEGIN
RETURN (NOT cur AND alive_nb = 3) OR alive_nb = 2 OR alive_nb = 3;
END;
$$ LANGUAGE plpgsql;
CREATE OR REPLACE FUNCTION life.next_universe(cur_uv BOOL [])
RETURNS BOOL [] AS $$
DECLARE
xl INT := array_length(cur_uv, 1);
yl INT := array_length(cur_uv, 2);
new_uv BOOL [] := array_fill(FALSE, ARRAY [xl, yl]);
BEGIN
FOR x IN 1..xl LOOP
FOR y IN 1..yl LOOP
new_uv [x] [y] = life.next_cell_state(cur_uv [x] [y], life.neighbor_alive_count(cur_uv, x, y));
END LOOP;
END LOOP;
RETURN new_uv;
END;
$$ LANGUAGE plpgsql IMMUTABLE STRICT;
CREATE OR REPLACE FUNCTION life.create_universe(size INT, fillrandom BOOL)
RETURNS BOOL [] AS $$
DECLARE
ret BOOL [] := NULL;
BEGIN
ret = array_fill(FALSE, ARRAY [size, size]);
IF fillrandom
THEN
FOR x IN 1..size LOOP
FOR y IN 1..size LOOP
ret [x] [y] = (random() * 100) :: INT % 2 = 0;
END LOOP;
END LOOP;
END IF;
RETURN ret;
END;
$$ LANGUAGE plpgsql;
CREATE OR REPLACE FUNCTION life.print_state(state BOOL [])
RETURNS VOID AS $$
DECLARE
line TEXT := '';
BEGIN
FOR x IN 1..array_length(state, 1) LOOP
FOR y IN 1..array_length(state, 2) LOOP
IF state [x] [y]
THEN
line := concat(line, 'X ');
ELSE
line := concat(line, ' ');
END IF;
END LOOP;
RAISE NOTICE '%', line;
line := '';
END LOOP;
END;
$$ LANGUAGE plpgsql;
CREATE OR REPLACE VIEW life.most_recent_state AS
SELECT s.state
FROM life.state s
ORDER BY s.generation DESC
LIMIT 1;
CREATE OR REPLACE FUNCTION life.game_of_life(boardsize INT)
RETURNS VOID AS $$
BEGIN
IF NOT exists(SELECT 1
FROM life.most_recent_state)
THEN
INSERT INTO life.state (state) SELECT life.create_universe(boardsize, TRUE);
ELSE
INSERT INTO life.state (state) SELECT life.next_universe((SELECT *
FROM life.most_recent_state));
END IF;
PERFORM life.print_state(boardsize, (SELECT *
FROM life.most_recent_state));
END;
$$ LANGUAGE plpgsql;
--SELECT life.game_of_life(6);
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