From: Robert Klemme <shortcutter@...>
Date: 2012-06-18T15:45:23+09:00
Subject: Re: Overwriting one Ruby array or arrays with another

On Wed, May 2, 2012 at 5:27 AM, Craig Law <lists@ruby-forum.com> wrote:
> Thanks for the reply
>
> I gave a fairly basic example so that I could explain my needs. Perhaps
> a little too basic. I'm also very new to Ruby.
>
> Going forward the array of arrays may hold information such as ...
>
> [1, 1, "X", "20120502"]
>
> ... so that I have a grid that will display an "X" at x,y coordinates
> 1,1 and also hold some metadata such as "20120502" which in this case
> would be a date.
>
> Ultimately I will be creating an HTML grid of variable size that will
> house an "X" or "O". The date would be metadata that I'm hoping to
> display when you hover over a box when viewing the grid/graph in a
> browser.
>
> If I can produce a hash of {[x, y] => xxxxx } which holds the values "X"
> and "20120501" that would be OK with me.
>
> Would the code for such a hash be something like this ...
>
> {[1, 1] => ["X", "20120501"]}
> {[1, 2] => ["O", "20120502"]}
>
> ... and if so how would I overwrite one hash with the other?

Frankly, I'd take a different approach: from what we have seen you
have a grid, coordinates and node data.  I'd rather model these as
separate classes, e.g.

https://gist.github.com/2947179

Now you can do

g = Grid.new 10, 500
g[Coord(1,3)] = NodeData.new "foo"

g.replace(
  Coord(1,2) => NodeData.new("hello"),
  Coord(2,34) => nil,
)

etc.

Then, if you find you need to change the internal representation to be
more efficient your algorithms are not affected since they just use
the same API of Grid.

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/