On Tue, 26 Jul 2005, Jon Harrop wrote:

> I came from a C++/STL background and was accustomed to using extensible
> arrays. Having tweaking my perception of suitable data structures to be more
> appropriate when coding in OCaml, I now prefer the idea of a faster run-time
> and no extensible arrays. I've never actually needed them (except inside
> Hashtbl).

Actually, they aren't needed in hashtbl either.  If you're resizing the 
array, you need to go through and rehash all the elements anyways, as many 
will need to be moved.  So you might as well copy them into a new array 
while you're at it.  And since you need to deal with hash collisions 
anyways, the easiest way is to make the underlying type really a 'a list 
array, which gives you an obvious empty element- the empty list.

No- variable length arrays are needed when you're implementing other data 
structures on top of arrays, like stacks or queues.  At which point I 
start asking which data structure you really need- a variable length 
array, or a stack or queue?

Brian