Rectangular Arrays

[Bill Baxter]

Another Roadside Attraction wrote:
> I'm learning D by writing a logic game with a grid-shaped board. If possible, I'd like to use a rectangular array for the board, but I'd like to define the width of the board at runtime when I instantiate the class. Ideally, I'd like to do something like this:
> 
> public class Board {
> 	
> 	private Piece[,] grid;
> 	
> 	public this(uint width) {
> 		grid = new Piece[width,width];
> 	}
> 
> }
> 
> But that doesn't compile. It looks like the dimensions of rectangular arrays has to be known at compile-time. Is that right, or am I missing something?
> 
> I've also tried declaring the array as an ordinary multi-dimensional array, but this doesn't compile either:
> 
> public class Board {
> 	
> 	private Piece[][] grid;
> 	
> 	public this(uint width) {
> 		grid = new Piece[width][width];
> 	}
> 
> }
> 
> What's the best way to write this code? As I expand on this project, I plan on incorporating some time-consuming algorithms (think, n-Queens problem), so I'd prefer to use the most efficent data structure possible for the board.
> 
> Thanks!!
> 
> --ARA

D doesn't have rectangular arrays at the moment.  But you can init a 
multi-dim ragged array.

http://www.digitalmars.com/d/expression.html#NewExpression

int[][][] bar = new int[][][](5,20,30);
or
auto bar = new int[][][](5,20,30);

I have some nd rectangular array at 
http://www.dsource.org/projects/multiarray
but it sounds like for your purposes the ragged array will be sufficient.

--bb