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From: minow@mountn.dec.com (Martin Minow)
Newsgroups: comp.std.c
Subject: Re: trigraphs
Message-ID: <38@mountn.dec.com>
Date: 28 Apr 89 15:26:25 GMT
References: <4623@freja.diku.dk> <12.UUL1.3#5077@aussie.UUCP> <2469@ogccse.ogc.edu>
Reply-To: minow@mountn.UUCP (Martin Minow)
Organization: Digital Equipment Corporation
Lines: 25

It was suggested that trigraphs were an established practice before ANSI
added them to the Draft Standard language definition.  Could someone
post a reference to a widely-distributed compiler that supported trigraphs
before 1984? As far as I know, neither pcc, Berkeley Unix, Decus C, Vax-C
(VMS), or Think (Lightspeed) C for the Macintosh support/supported trigraphs.

I had argued against them on comp.std.c and during all public comment periods
(though I've never actually received a written reply directly from the
committee). My argument is that ISO 646 is a dead standard, having been
supplemented by ISO 8859 (Latin-x).  In the first public review responses,
a half-dozen writers, including at least one from Sweden and one from Canada,
suggested removing trigraphs. The committee response -- in full -- was
  "The Committee discussed alternatives to trigraphs on a number
  of occasions, but always decided that they fill a need.  C must
  support a wide variety of terminals and keyboards, many of which
  lack the full C character set."
While I understand the issues and sympathize with the problems the USASCII-
specific characters pose for implementors (I am bilingual Swedish-English
and have worked as a programmer in Sweden), they pose unsolvable problems
for implementors and are as necessary today as a modified C for upper-case
only terminals was in 1978 (when the VT05 and ASR33 were still in wide use).

Martin Minow
minow%thundr.dec@decwrl.dec.com
The above does not represent the position of Digital Equipment Corporation.