> Mats wrote

> > OK, sure.  But readnext doesn't  really work on an array
> > but on a select list.

Will wrote:

> Ah but that's not so.
> You can SELECT myVAR
> You can SELECT myVAR to LIST5
> You can SELECT myVAR to MyLIST
>
> and then you *can* in fact READNEXT your array.  Selecting
> the variable turns a dynamic array into a list type variable.

Not wanting to put words in Mats' mouth, but I expect he meant that READNEXT
didn't work on arrays in the traditional sense.  And by that, I don't mean
the traditional PICK sense, but the general programming sense.  An array in
most languages is a collection of (normally similar) objects which can be
operated on either in sequence or at random because the array mechanism
provides primitives to do that neatly and efficiently.

READNEXT can only ever process a select list - a structure that is in many
ways like a dynamic array *EXCEPT* that you can't work with any item except
the first.  Yes, it is easy to map an array into a select list, and
vice-versa, but you can't address the 23rd element of a select list without
processing the first 22.  Some would say the same of a dynamic array
because, under the covers, BASIC pretty much does that anyway, but
semantically you can address any element of a dynamic array at any time,
while semantically, BASIC provides no such mechanism for a select list.

Cheers,

Ken
-------
u2-users mailing list
u2-users@listserver.u2ug.org
To unsubscribe please visit http://listserver.u2ug.org/

Reply via email to