[REBOL] Re: [data structures]
From: joel::neely::fedex::com at: 20-Nov-2003 18:05
Hi, Gregg,
Gregg Irwin wrote:
> ... For example, how would
> we build constructs in REBOL to emulate what Perl does with
> auto-sizing arrays,
Exactly what I was hoping for. As an example, I've been using the
nested-block trick to simulate mutable arrays in REBOL for some time,
and have no specific problem/complaint with it (other than the fact
that it looks a bit funny... ;-) However, I was hoping for some
additional suggestions from the list.
> or what would a Perlite/Perler/Perl-monger (proper
> term?) do to provide protection *against* auto-sizing if it wasn't
> desired.
I can think of three alternatives right off:
++$array[$n] if $minOK <= $n && $n <= $maxOK;
to ignore OOBVs (out-of-bounds values),
++$array[$n < $minOK ? $minOK : $maxOK < $n ? $maxOK : $n];
to force OOBVs to the violated boundary, or
++$array[$minOK <= $n && $n <= $maxOK ? $n : $default];
to force OOBVs to some default bucket. The last two index expressions
(for those not familiar with C or Perl) are essentially equivalent to
the REBOL expressions
either n < minOK [minOK] [either maxOK < n [maxOK] [n]]
and
either all [minOK <= n n <= maxOK] [n] [default]
I'd actually write the first of these in REBOL as
max minOK min maxOK n
To say that in Perl one would need to define the min and max functions,
as they aren't built in.
-jn-
