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Date: Mon, 20 May 2013 16:07:51 +1000
From: Cameron Simpson <cs@zip.com.au>
To: Gregory Ewing <greg.ewing@canterbury.ac.nz>
Subject: Re: mutable ints: I think I have painted myself into a corner
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On 20May2013 13:23, Greg Ewing <greg.ewing@canterbury.ac.nz> wrote:
| Cameron Simpson wrote:
| >It's an int _subclass_ so that it is no bigger than an int.
| 
| If you use __slots__ to eliminate the overhead of an
| instance dict, you'll get an object consisting of a
| header plus one reference, which is probably about the
| size of an int. But you'll also need an int to put in
| that slot, so the total size will be about twice that
| of an int.

Yeah, I was thinking I'd need to go that way. Thanks for the
suggestion.

| Another approach would be to subclass array.array and
| give instances of it type integer and size 1. Together
| with empty __slots__, it will probably be a bit bigger
| than an int, but it might still be smaller than a
| custom object plus an int.

Really? Interesting. I thinik it crosses my "too baroque" threshold,
but maybe not:-)

| If all of these are still too big, you might need to
| find some way of packing multiple instances into a
| single array.array.

Space isn't that real an issue at present; I'll keep that kind of
approach in mind if it comes up. This really came up because I was
feeling that the obvious object-with-boolean-attributes was terrbily
wasteful for something that can be inplemented with a single int,
in principle.

Cheers,
-- 
Cameron Simpson <cs@zip.com.au>

>>>How do you blip the throttle and wave? Do you blip it real high, then wave
>>>before the revs drop back?
>>Blip = right hand; Wave = left hand.  Do both simultaneously.  QED.
>Doesnt this make the bike lurch forward thru the intersection?
Not if the disk lock is in place...
        - Dean Woodward <deanw@agora.rdrop.com>