Directly modify a part on an array for quiz #117 purposes

Ruby
1

From Ruby quiz #117 (much fun)

#bad code by me, interesting bits shamelessly stolen from Dave B.
neighborhood=[@grid[x0][y0], @grid[x0][y1], @grid[x1][y0],
@grid[x1][y1]]

where each element of @grid[][] is a string, x1 = x0+1, and y1=y0+1

is there a way to do the following:
@grid[x0][y0], @grid[x0][y1], @grid[x1][y0], @grid[x1][y1] =
@grid[x1][y0],
@grid[x0][y0], @grid[x1][y1], @grid[x0][y1]

in a more readable way

I thought

*neighborhood = @grid[x1][y0], @grid[x0][y0], @grid[x1][y1],
@grid[x0][y1]

would be equivalent, but it isn’t.

2

On Mar 11, 2007, at 20:24 , Albert Ng wrote:

[x1][y0],
@grid[x0][y0], @grid[x1][y1], @grid[x0][y1]

in a more readable way

I thought

*neighborhood = @grid[x1][y0], @grid[x0][y0], @grid[x1][y1], @grid
[x0][y1]

would be equivalent, but it isn’t.

Did you have a look at my code?

I used this:

2.times do |y|
2.times do |x|
class_eval “def xy#{x}#{y}; @grid[@x + #{x}, @y + #{y}]; end”
class_eval “def xy#{x}#{y}=(v); @grid[@x + #{x}, @y + #{y}] = v;
end”
end
end

To allow me to write the rotations as

 def ccw90
   self.xy00, self.xy10, self.xy01, self.xy11 = xy10, xy11, xy00,

xy01
end

 def cw90
   self.xy00, self.xy10, self.xy01, self.xy11 = xy01, xy00, xy11,

xy10
end

Might be an idea?

/Christoffer

3

that’s neat, I’ll keep it in mind :slight_smile: