Morton Goldberg
9/3/2007 2:24:00 PM
On Sep 3, 2007, at 8:40 AM, Joop Van den tillaart wrote:
> Is there no one else who can help me out a bit?
OK, I'll make some suggestions.
1. I think you could make your life a lot easier if you gave your
cell objects more info about where they live.
2. I suggest you fill @grid with cells during initialization.
3. I suggest you include Enumerable in your Grid class. Then you only
have to define Grid#each to get map, collect, and whole more for free.
<code>
class Cell
attr_accessor :type, :distance_road
attr_reader :i
def initialize(grid, i)
@my_grid = grid
@i = i
end
def xy
@i.divmod(@my_grid.width).reverse
end
def inspect
"Cell[#{@i}, #{xy.inspect}, #{type}, #{distance_road}]"
end
end
class Grid
include Enumerable
attr :width, :heigh
def initialize(width, height)
@grid = Array.new(width * height) { |i| Cell.new(self, i) }
@width = width
@height = height
end
def [](x, y)
raise IndexError.new("Index (#{x}, #{y}) out of range") if x < 0 || y < 0 || x >= @width || y >= @width
@grid[y * width + x]
end
def []=(x, y, value)
raise IndexError.new("Index (#{x}, #{y}) out of range") if x < 0 || y < 0 || x >= @width || y >= @width
@grid[y * width + x] = value
end
def each
@grid.each { |cell| yield cell }
end
end
# Now you can do all kinds of neat things.
g = Grid.new(2, 2)
p g
g.map { |cell| cell.type = 0; cell.distance_road = cell.i % 2 }
p g
h = g.select { |cell| cell.distance_road == 1 }
h.each { |cell| cell.type = 42 }
p g
p g.any? { |cell| cell.type == 42 }
p g.all? { |cell| g[*cell.xy] == cell }
</code>
<result>
#<Grid:0x7b128 @width=2,
@grid=[Cell[0, [0, 0], , ], Cell[1, [1, 0], , ],
Cell[2, [0, 1], , ], Cell[3, [1, 1], , ]],
@height=2>
#<Grid:0x7b1a0 @width=2,
@grid=[Cell[0, [0, 0], 0, 0], Cell[1, [1, 0], 0, 1],
Cell[2, [0, 1], 0, 0], Cell[3, [1, 1], 0, 1]],
@height=2>
#<Grid:0x7b1a0 @width=2,
@grid=[Cell[0, [0, 0], 0, 0], Cell[1, [1, 0], 42, 1],
Cell[2, [0, 1], 0, 0], Cell[3, [1, 1], 42, 1]],
@height=2>
true
true
</result>
Regards, Morton