From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org
X-Spam-Level: 
X-Spam-Status: No, score=-1.0 required=5.0 tests=MAILING_LIST_MULTI,
	T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4
Received: (qmail 13506 invoked from network); 11 Aug 2022 07:37:57 -0000
Received: from minnie.tuhs.org (50.116.15.146)
  by inbox.vuxu.org with ESMTPUTF8; 11 Aug 2022 07:37:57 -0000
Received: from minnie.tuhs.org (localhost [IPv6:::1])
	by minnie.tuhs.org (Postfix) with ESMTP id 7C099404ED;
	Thu, 11 Aug 2022 17:37:52 +1000 (AEST)
Received: from relay05.pair.com (relay05.pair.com [216.92.24.67])
	by minnie.tuhs.org (Postfix) with ESMTPS id E0E8D4001F
	for <tuhs@tuhs.org>; Thu, 11 Aug 2022 17:37:47 +1000 (AEST)
Received: from orac.inputplus.co.uk (unknown [84.51.159.66])
	by relay05.pair.com (Postfix) with ESMTP id BF71A1A2724
	for <tuhs@tuhs.org>; Thu, 11 Aug 2022 03:37:46 -0400 (EDT)
Received: from orac.inputplus.co.uk (orac.inputplus.co.uk [IPv6:::1])
	by orac.inputplus.co.uk (Postfix) with ESMTP id 848C2218D8
	for <tuhs@tuhs.org>; Thu, 11 Aug 2022 08:37:45 +0100 (BST)
To: tuhs@tuhs.org
From: Ralph Corderoy <ralph@inputplus.co.uk>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
In-reply-to: <20220810180210.GZ21168@mcvoy.com>
References: <CAKH6PiWYOP+G4bOa6vH_GzDnPbpwMW9qXb=_=-Vh5D7mynYMXA@mail.gmail.com> <202208101505.27AF5Ko7020961@freefriends.org> <20220810171417.GY21168@mcvoy.com> <202208101737.27AHbupN011923@freefriends.org> <202208101744.27AHiWOT1220324@darkstar.fourwinds.com> <20220810180210.GZ21168@mcvoy.com>
Date: Thu, 11 Aug 2022 08:37:45 +0100
Message-Id: <20220811073745.848C2218D8@orac.inputplus.co.uk>
Message-ID-Hash: OLZ3XZWNJEMBMBSVSWDAZJBIZ2NOWLOX
X-Message-ID-Hash: OLZ3XZWNJEMBMBSVSWDAZJBIZ2NOWLOX
X-MailFrom: ralph@inputplus.co.uk
X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-tuhs.tuhs.org-0; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header
X-Mailman-Version: 3.3.6b1
Precedence: list
Subject: [TUHS] Re: pic's One-way Information Flow. (Was: SNOBOL and RATSNO)
List-Id: The Unix Heritage Society mailing list <tuhs.tuhs.org>
Archived-At: <https://www.tuhs.org/mailman3/hyperkitty/list/tuhs@tuhs.org/message/OLZ3XZWNJEMBMBSVSWDAZJBIZ2NOWLOX/>
List-Archive: <https://www.tuhs.org/mailman3/hyperkitty/list/tuhs@tuhs.org/>
List-Help: <mailto:tuhs-request@tuhs.org?subject=help>
List-Owner: <mailto:tuhs-owner@tuhs.org>
List-Post: <mailto:tuhs@tuhs.org>
List-Subscribe: <mailto:tuhs-join@tuhs.org>
List-Unsubscribe: <mailto:tuhs-leave@tuhs.org>

Hi Larry,

> Also agree with the "box that fits this text" problem, pic really
> could use a sizeof("this text in the current font/point size/line
> spacing") that returns x,y.  But I don't see how to do that because
> pic doesn't have that info, pic would need to be able to ask troff
> what those are.

Rather than work out the coordinates of everything, could pic punt some
of that downstream to troff by producing expressions which rest on
variables set by troff to, say, the width of a diversion.  The order of
evaluation presented to troff would obviously have to be topological on
the dependencies which bars cycles.  It would add elasticity to a
drawing.

The other approach would be a multi-pass effort where pic initially
assumes unknown dimensions, like some text's width, but also outputs
troff which will store the actual width for input to pic on future runs.

-- 
Cheers, Ralph.