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Re: looping through a list, starting at 1

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Arved Sandstrom <asandstrom3minus1@eastlink.ca> wrote:
> On 11-08-10 07:50 PM, Andreas Leitgeb wrote:
>> How would I write a method (overload) that would only take an
>> object if it is both List and RandomAccess? (Afaik: no way, but
>> I might perhaps miss something.)
> Pretty much in the standard way, which would take advantage of the
> marker interface in a way suggested by Bloch: you create an interface
> that extends List and RandomAccess, and concrete classes implement that.

That's just not applicable to the Collections framework as it is:
We've all been taught to use interface-names for the static type
of variables to hold whatever concrete implementation:
  ArrayList l = new ArrayList();  // discouraged
  List l = new ArrayList();       // encouraged

As soon as I use a statically "List"-typed variable to hold my
ArrayList instance, I've irrevocably disposed of the *static*
information about RandomAccess'ness of the instance.

If we were to change the Collection framework to allow for static
dealing with RandomAccess'ness, then we would first need that new
  interface RandomAccessList extends List,RandomAccess {}
and would then need all appropriate implementations to implement
that new interface. And also we would need to statically type
certain variables as RandomAccessList, if we really wanted the
compiler to be able to statically decide among a RandomAccess-
optimized code path or the default one (without locking in on
particular implementations).

That's of course just rambling.  Marker-interfaces just aren't used that
way, but instead they are always checked at runtime. So, either Marker-
interfaces (such as RandomAccess) are an anti-pattern themselves, or
that pattern is one declared exception to the "instanceof"-red flag.

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Re: looping through a list, starting at 1 Arne Vajhøj <arne@vajhoej.dk> - 2011-08-01 20:32 -0400
  Re: looping through a list, starting at 1 Robert Klemme <shortcutter@googlemail.com> - 2011-08-02 02:42 -0700
    Re: looping through a list, starting at 1 v_borchert@despammed.com (Volker Borchert) - 2011-08-02 19:32 +0000
      Re: looping through a list, starting at 1 Lew <lewbloch@gmail.com> - 2011-08-10 09:00 -0700
        Re: looping through a list, starting at 1 Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-10 21:39 +0000
          Re: looping through a list, starting at 1 Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-08-10 19:10 -0300
            Re: looping through a list, starting at 1 Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-10 22:50 +0000
              Re: looping through a list, starting at 1 Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-08-11 07:02 -0300
                Re: looping through a list, starting at 1 Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-11 11:37 +0000
                Re: looping through a list, starting at 1 Lew <lewbloch@gmail.com> - 2011-08-11 07:14 -0700
                Re: looping through a list, starting at 1 Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-11 16:18 +0000
                Re: looping through a list, starting at 1 Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-08-11 17:39 -0300
                Re: looping through a list, starting at 1 Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-12 08:09 +0000
                Re: looping through a list, starting at 1 supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-08-11 09:52 -0400
                Re: looping through a list, starting at 1 Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-08-11 17:26 -0300
                Re: looping through a list, starting at 1 supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-08-11 20:11 -0400
          Re: looping through a list, starting at 1 Lew <lewbloch@gmail.com> - 2011-08-10 20:31 -0700
            Re: looping through a list, starting at 1 Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-11 16:07 +0000
              Re: looping through a list, starting at 1 Lew <lewbloch@gmail.com> - 2011-08-11 09:20 -0700
                Re: looping through a list, starting at 1 Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-11 18:03 +0000
                Re: looping through a list, starting at 1 Lew <lewbloch@gmail.com> - 2011-08-11 12:55 -0700
                Re: looping through a list, starting at 1 Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-12 08:32 +0000
                Re: looping through a list, starting at 1 supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-08-12 09:09 -0400
                Re: looping through a list, starting at 1 Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-12 14:38 +0000
                Re: looping through a list, starting at 1 Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-08-12 14:51 +0000

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