life.abe

--- Conway's "Game of Life" built on the Actor model

int_generator =
	BEHAVIOR {step, limit, label, ctx, send-to}
	{next:$next} ->
		IF preceeds(0, $step)
		END
	DONE

int_generator(next:<next>){step:<step>, limit:<limit>, label:<label>, ctx:<ctx>, send-to:<send-to>} =
	IF preceeds?(0, <step>)
		IF NOT preceeds?(<limit>, <next>)
			map_put(<ctx>, <label>, <next>) => <send-to>
			{next:sum(<next>, <step>)} => self()
	ELSE
		IF NOT preceeds?(<next>, <limit>)
			map_put(<ctx>, <label>, <next>) => <send-to>
			{next:sum(<next>, <step>)} => self()

seq_generator(<msg>){next:<next>, step:<step>, limit:<limit>, label:<label>, ctx:<ctx>, send-to:<send-to>} =
	<ctx> := map_put_all(<ctx>, <msg>)
	{next:<next>} => actor(int_generator, {step:<step>, limit:<limit>, label:<label>, ctx:<ctx>, send-to:<send-to>})

cell_actor(request:<request>, reply-to:<reply-to>){value:<value>, x:<x>, y:<y>} =
	IF equal?(<request>, update-grid)
		set_grid_value(<x>, <y>, <value>)
	ELIF equal?(<request>, gen-next)
		<n> := count_neighbors(<x>, <y>)
		IF equal?(<value>, EMPTY)
			IF equal?(<n>, 3)
				become(cell_actor, {value:FULL, x:<x>, y:<y>})
		ELIF equal?(<value>, FULL)
			IF preceed?(<n>, 2) OR preceed?(3, <n>)
				become(cell_actor, {value:FULL, x:<x>, y:<y>})
	ELIF equal?(<request>, die)
		set_grid_value(<x>, <y>, DEAD)

ask_cell(x:<x>, y:<y>){request:<request>, reply-to:<reply-to>} =
	<cell> := get_cell(<x>, <y>)
	{request:<request>, reply-to:<reply-to>} => <cell>

ask_all_cells(request:<request>, reply-to:<reply-to>){} =
	<cell> := actor(ask_cell, {request:<request>, reply-to:<reply-to>})
	<cols> := actor(seq_generator,
		{next:0, step:1, limit:(<y-max> - 1), label:y, ctx:(), send-to:<cell>})
	<rows> := actor(int_generator,
		{step:1, limit:(<x-max> - 1), label:x, ctx:(), send-to:<cols>})
	{next:0} => <rows>