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From: Stefan Monnier <monnier@iro.umontreal.ca>
To: emacs-devel@gnu.org
Subject: Re: How to quickly compare equality of structs ...
Date: Mon, 06 May 2019 20:49:23 -0400	[thread overview]
Message-ID: <jwvr29bgki1.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: m2r29b18tj.wl%esq@lawlist.com

> This afternoon, I came across the Cantor's Pairing Function that can be used
> to create a unique ID for each fake cursor.  With that unique ID, I can
> limit the quantity of comparisons ....
>  n = ((x + y)*(x + y + 1)/2) + y

Not sure why you care about limiting the number of comparisons.
Replacing two comparisons with one-comparison-plus-two-mults (and
reducing the range of x and y to sqrt(MAXINT) along thre way) doesn't
sound like much of a win.


        Stefan




  reply	other threads:[~2019-05-07  0:49 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-06 23:07 How to quickly compare equality of structs Keith David Bershatsky
2019-05-07  0:49 ` Stefan Monnier [this message]
  -- strict thread matches above, loose matches on Subject: below --
2019-05-07  2:59 Keith David Bershatsky
2019-05-07 12:41 ` Stefan Monnier
2019-05-06 20:40 Keith David Bershatsky
2019-05-06 21:22 ` Paul Eggert
2019-05-06 18:55 Keith David Bershatsky
2019-05-06 19:00 ` Paul Eggert

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