How do you represent a rectangular 2-dimensional (or multidimensional) array data structure in Scala?
That is, each row has the same length, verified at compile time, but the dimensions are determined at runtime?
Seq[Seq[A]] has the desired interface, but it permits the user to provide a "ragged" array, which can result in a run-time failure.
Seq[(A, A, A, A, A, A)] (and similar) does verify that the lengths are the same, but it also forces this length to be specified at compile time.
Example interface
Here's an example interface of what I mean (of course, the inner dimension doesn't have to be tuples; it could be specified as lists or some other type):
// Function that takes a rectangular array
def processArray(arr : RectArray2D[Int]) = {
// do something that assumes all rows of RectArray are the same length
}
// Calling the function (OK)
println(processArray(RectArray2D(
( 0, 1, 2, 3),
(10, 11, 12, 13),
(20, 21, 22, 23)
)))
// Compile-time error
println(processArray(RectArray2D(
( 0, 1, 2, 3),
(10, 11, 12),
(20, 21, 22, 23, 24)
)))