From: Andy Wingo <wingo@pobox.com>
To: Panicz Maciej Godek <godek.maciek@gmail.com>
Cc: guile-user@gnu.org
Subject: Re: Reader syntax for accessing arrays
Date: Mon, 09 Jan 2012 16:39:41 +0100 [thread overview]
Message-ID: <87hb04996q.fsf@pobox.com> (raw)
In-Reply-To: <CAMFYt2ZqK7ax7uU3os0c+Oe_gGFY0aiPsHoVdCc_Zu2Xe41GeQ@mail.gmail.com> (Panicz Maciej Godek's message of "Tue, 23 Aug 2011 01:17:38 +0200")
On Tue 23 Aug 2011 01:17, Panicz Maciej Godek <godek.maciek@gmail.com> writes:
> (array-set! a (* (array-ref a i j) 2) i j))
> seems to be unnecessarily prolix, for in C, language designed
> specifically to access arrays,
> the same operation could be written as
> a[i][j] *= 2;
With the appropriate macrology, it could look different:
(with-array-cells ((x (array-ref a i j)))
(set! x (* x 2)))
Seems OK to me. There are other possibilities. The macro:
(define-syntax with-array-cells
(syntax-rules (array-ref)
((_ ((sym (array-ref a idx ...)) ...) body body* ...)
(let-syntax ((sym (identifier-syntax
(var (array-ref a idx ...))
((set! var val) (array-set! a val idx ...))))
...)
body body* ...))))
Regards,
Andy
--
http://wingolog.org/
prev parent reply other threads:[~2012-01-09 15:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-22 23:17 Reader syntax for accessing arrays Panicz Maciej Godek
2011-08-23 8:10 ` Johan Hidding
2011-08-23 18:03 ` Panicz Maciej Godek
2011-08-24 10:51 ` Ludovic Courtès
2011-08-24 18:45 ` Panicz Maciej Godek
2011-08-24 19:52 ` Johan Hidding
2011-08-26 21:02 ` Panicz Maciej Godek
2012-01-09 15:39 ` Andy Wingo [this message]
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