-- Evolution of the world in the Game of Life
--
-- NAME, STUDENT NUMBER   <-- ADD YOUR DETAILS HERE

module GameOfLife (initWorld, evolve, Cell, Board, Location, World)
where

-- Data types to be used represent the world state in the Game of Life
-- -------------------------------------------------------------------

-- Type used to denote a single cell on the board
--
-- * The value `True' represents live cells
--
type Cell = Bool

-- Representation of the board on which the Game of Life unfolds
--
-- * Each sublist represents a column of the board
--
-- * The cell represented by the the first element of the first column is
--   located at the lower left corner of the board when displayed
--
type Board = [[Cell]]

-- The type used to index the board in the Game of Life
--
-- * The location "(0, 0)" represents the lower left corner of the board (ie,
--   the origin of the world)
--
type Location = (Int, Int)

-- Representation of the world
--
-- * The location determines the index of top right corner of the board (ie,
--   the corner opposite of the origin); indicies for the board can range from
--   "(0,0)" up to that location.
--
type World = (Location, Board)


-- The main functions
-- ------------------

-- Initialise the world from a string
--
-- * The character '*' represents live cells
--
-- * The characeter '.' represents dead cells
--
-- * Each row of the board is terminated by a newline
--
-- initWorld ".*.\n.*.\n***\n" 
--   => 
-- ((2,2),[[True,False,False],[True,True,True],[True,False,False]])
--
-- We shall call this "worldExample" in the following comments.
--
-- ADD YOUR OWN SAMPLE INVOCATIONS
--
initWorld :: String -> World
initWorld = error "The function initWorld is not implemented yet"

-- Given a world in the game, produce the next state of the world
--
-- evolve ((2,2),[[True,False,False],[True,True,True],[True,False,False]])
--  =>
-- ((2,2),[[True,False,False],[True,False,False],[True,False,False]])
--
-- ADD YOUR OWN SAMPLE INVOCATIONS
--
evolve :: World -> World
evolve = error "The function evolve is not implemented"


-- Some auxilliary functions for computing new world states
-- --------------------------------------------------------

-- Given a game world and a location, yield the liveness at that location
--
-- getCell worldExample (0,1) => False
-- getCell worldExample (1,1) => True
-- getCell worldExample (5,5) => *** Exception: Cell (5,5) is out of bounds
--
-- ADD YOUR OWN SAMPLE INVOCATIONS
--
getCell :: World -> Location -> Cell
getCell = error "The function getCell is not implemented"

-- Update a location in the world with the given liveness
--
-- setCell worldExample (0,0) False 
--  =>
-- ((2,2),[[False,False,False],[True,True,True],[True,False,False]])
-- setCell worldExample (3,4) True 
--   => 
-- *** Exception: Cell (3,4) is out of bounds
--
-- ADD YOUR OWN SAMPLE INVOCATIONS
--
setCell :: World -> Location -> Cell -> World
setCell = error "The function setCell is not implemented"

-- Compute the next-generation state for the cell at the given location
-- 
-- evolveCell worldExample (1,1) => False
-- evolveCell worldExample (2,0) => True
-- ADD YOUR OWN SAMPLE INVOCATIONS
--
evolveCell :: World -> Location -> Cell
evolveCell = error "The function evolveCell is not implemented"