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precedent: more useful error codes. (VAX/VMS flashback)

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William Lindley
January 26, 2022 13:57
precedent: more useful error codes. (VAX/VMS flashback)
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On 1/25/22 8:05 PM, Tom Molesworth via perl5-porters wrote:
> Could we move over to a common object-based format, for example - one
> that provides message, diagnostic information, error codes, categories
> and/or tags?

Applicable precedent would be VMS error code format; apt since DEC's
BASIC-PLUS was "an ancient language from which Perl derived exactly one
idea [or maybe two, per footnote]" -- Programming Perl, first edition,
p. 414.  VMS errors (1975) nearly predate the concept of object-oriented
programming (except Smalltalk 72 and a few others) but the goal is
identical: Make understanding and debugging errors easy.

For example, in VMS style (facility, level [I=informational, W=warning,
E=error], identification, text), we might have had:

  %PERL-W-WIDECHAR, Wide character in print at -e line 1.

which isn't much nicer but at least the error code is easily found in an
index or search.  (In actuality, error codes were passed to the OS as
integers and the text came from a disk file, RAM being more precious in
those days, a convergence of utility and usefulness.) A recent
explanation of this heritage format is


p.s., Actually, I wonder what the VMS port of Perl used for error
codes... anyone got Perl on a simh VAX/VMS instance?

p.p.s., My high-school job was BASIC-PLUS/2 programming on a PDP-11/40,
with TECO on an ADM-3 (not -3A, none of that fancy addressable cursor
stuff for us lowly programmers, even those of us with PPNs that started
with 1,).  VAX (and a VT-100) came soon after, and BASIC-PLUS/2 happily
recompiled our existing programs for VMS, huzzah!  0lt$$

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