A simple 2D-Array implementation.

Neither storing nor sorting (otherwise inherited from ArrayedCollection) will work. Neither comparing nor most accessing mehods inherited from Sequenceable collection will work. Actually, it's a bad idea to inherit this class from collection at all!

	accessing rows/columns
	atCol: atCol:put: atRow: atRow:put:

	converting
	asArray

	copying
	copy

	enumeration
	do: rowAndColumnValuesDo: rowsAndColumnsDo:

	private
	extent:fromArray: indexX:y: setContents: width:height:type:

	accessing	top
	at:at: Answer the element at index x,y.
	at:at:add: Add value (using #+) to the existing element at index x,y.
	at:at:put: Store value at index x,y and answer it.
	atAllPut: Put anObject at every one of the receiver's indices.
	extent Answer the receiver's dimensions as point.
	height Answer the receiver's second dimension.
	size Answer how many elements the receiver contains.
	width Answer the receiver's first dimension.

	accessing rows/columns	top
	atCol: Answer a whole column.
	atCol:put: Put in a whole column.
	atRow: Answer a whole row.
	atRow:put: Put in a whole row.

	converting	top
	asArray Answer an Array whose elements are the elements of the receiver.

	copying	top
	copy Answer another instance just like the receiver. Subclasses typically override this method; they typically do not override shallowCopy.

	enumeration	top
	do: Iterate with X varying most quickly. 6/20/96 tk
	rowAndColumnValuesDo:
	rowsAndColumnsDo:

	private	top
	extent:fromArray: Load receiver up from a 1-D array. X varies most quickly. 6/20/96 tk
	indexX:y:
	setContents:
	width:height:type: Set the number of elements in the first and second dimension. collectionClass can be Array or String or ByteArray.

	instance creation	top
	extent:
	new Override ArrayedCollection. 6/20/96 tk
	new: Answer an instance of this class with the number of indexable variables specified by the argument, sizeRequested.
	width:height:
	width:height:type: