Re: PL/I exceptions, was catch and throw, was Is multi-level function return possible?

From	glen herrmannsfeldt <gah@ugcs.caltech.edu>
Newsgroups	comp.compilers
Subject	Re: PL/I exceptions, was catch and throw, was Is multi-level function return possible?
Date	2014-03-29 02:40 +0000
Organization	Aioe.org NNTP Server
Message-ID	<14-03-079@comp.compilers> (permalink)
References	<14-03-065@comp.compilers> <14-03-068@comp.compilers> <14-03-070@comp.compilers> <14-03-076@comp.compilers>

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mac <acolvin@efunct.com> wrote:

(snip on PL/I ON units)

> Not quite the same. ON defined a handler invoked at the signal site. It
> could attempt repair and return. more like an interrupt. However, the
> typical handler did a non-local GOTO to bail out, clearing any calls
> between the signal and the gone-to label.

One I remember, but maybe no-one does anymore. You can use ON ENDPAGE
to paginate output. When an attempt is made to print a line past the
end of the page (an attribute of printable output files) the ENDPAGE
ON unit is executed, which skips to the next page and prints any page
headers.  Then return and let the output continue.

ENDFILE, on the other hand, (on input files) most likely goes on to
process the data. It might be that you could close the file, open a
new one and continue on. I never tried that.

For CONVERSION, you can test the invalid character, and, if desired,
replace it with a different one.

For SUBSCRIPTRANGE and STRINGRANGE there likely isn't much to do,
maybe just print a message. You could go process something else, but
usually not much point in trying again.

Java's try/catch, on the other hand, does not have the ability
to fix up and continue.

-- glen
[ON ENDPAGE was probably to help convert COBOL report writer programs. It's
in the PL/I standard, not just an IBM-ism.  -John]

Thread

Is multi-level function return possible? noitalmost <noitalmost@cox.net> - 2014-03-10 15:46 -0400
  Re: Is multi-level function return possible? Kaz Kylheku <kaz@kylheku.com> - 2014-03-11 05:20 +0000
  Re: Is multi-level function return possible? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-03-11 13:04 +0000
    Re: Is multi-level function return possible? Kaz Kylheku <kaz@kylheku.com> - 2014-03-11 22:15 +0000
      Re: Is multi-level function return possible? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-03-13 17:05 +0000
        Re: Is multi-level function return possible? Bill Findlay <yaldnif.w@blueyonder.co.uk> - 2014-03-14 01:28 +0000
        Re: Is multi-level function return possible? Ivan Godard <ivan@ootbcomp.com> - 2014-03-13 18:32 -0700
          Re: Is multi-level function return possible? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-14 20:27 +0000
      Re: Is multi-level function return possible? George Neuner <gneuner2@comcast.net> - 2014-03-14 02:39 -0400
        Re: Is multi-level function return possible? Kaz Kylheku <kaz@kylheku.com> - 2014-03-14 21:34 +0000
          Re: Is multi-level function return possible? Marco van de Voort <marcov@toad.stack.nl> - 2014-03-14 22:59 +0000
        Re: Is multi-level function return possible? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-03-16 17:19 +0000
          Re: Is multi-level function return possible? Marco van de Voort <marcov@toad.stack.nl> - 2014-03-16 18:39 +0000
          Re: Is multi-level function return possible? Andy Walker <news@cuboid.co.uk> - 2014-03-16 19:45 +0000
            Re: Is multi-level function return possible? Bill Findlay <yaldnif.w@blueyonder.co.uk> - 2014-03-17 16:15 +0000
              Re: Is multi-level function return possible? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-03-18 17:36 +0000
                Re: Is multi-level function return possible? Andy Walker <news@cuboid.co.uk> - 2014-03-21 02:04 +0000
                Re: Is multi-level function return possible? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-21 02:50 +0000
                Re: design of PL/I, was Is multi-level function return possible? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-21 06:43 +0000
                Re: design of PL/I, was Is multi-level function return possible? noitalmost <noitalmost@cox.net> - 2014-03-26 14:16 -0400
                Re: exception catching in PL/I, was Is multi-level function return possible? "Robin Vowels" <robin51@dodo.com.au> - 2014-03-27 21:08 +1100
                Re: Is multi-level function return possible? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-03-24 17:06 +0000
                Re: Is multi-level function return possible? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-24 20:01 +0000
                Re: Is multi-level function return possible? George Neuner <gneuner2@comcast.net> - 2014-03-26 04:00 -0400
                Re: Is multi-level function return possible? Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2014-03-27 01:58 +0100
                Re: Is multi-level function return possible? Stefan Monnier <monnier@iro.umontreal.ca> - 2014-04-07 14:48 -0400
                Re: Is multi-level function return possible? Andy Walker <news@cuboid.co.uk> - 2014-03-26 12:16 +0000
                Re: Is multi-level function return possible? Andy Walker <news@cuboid.co.uk> - 2014-03-26 17:34 +0000
                Re: history of C, was Is multi-level function return possible? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-27 00:05 +0000
      Re: Is multi-level function return possible? Bakul Shah <usenet@bitblocks.com> - 2014-03-15 10:28 -0700
    Re: Is multi-level function return possible? George Neuner <gneuner2@comcast.net> - 2014-03-14 02:44 -0400
      Re: Is multi-level function return possible? Marco van de Voort <marcov@toad.stack.nl> - 2014-03-14 19:38 +0000
      Re: Is multi-level function return possible? Kaz Kylheku <kaz@kylheku.com> - 2014-03-14 21:36 +0000
      Re: Is multi-level function return possible? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-14 21:47 +0000
        Re: Is multi-level function return possible? Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2014-03-15 13:34 +0100
      Re: Is multi-level function return possible? Ian Lance Taylor <ian@airs.com> - 2014-03-14 16:55 -0700
  Re: Is multi-level function return possible? George Neuner <gneuner2@comcast.net> - 2014-03-11 13:56 -0400
    Re: Is multi-level function return possible? federation2005@netzero.com - 2014-03-26 17:39 -0700
      Re: catch and throw, was Is multi-level function return possible? rpw3@rpw3.org (Rob Warnock) - 2014-03-27 04:23 +0000
        Re: catch and throw, was Is multi-level function return possible? Kaz Kylheku <kaz@kylheku.com> - 2014-03-27 05:44 +0000
        Re: catch and throw, was Is multi-level function return possible? Bakul Shah <usenet@bitblocks.com> - 2014-03-26 23:20 -0700
          Re: catch and throw, was Is multi-level function return possible? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-27 19:21 +0000
          Re: exception catching in PL/I "Robin Vowels" <robin51@dodo.com.au> - 2014-03-28 10:50 +1100
            Re: exception catching in PL/I Martin Ward <martin@gkc.org.uk> - 2014-04-16 14:32 +0100
          Re: catch and throw, was Is multi-level function return possible? mac <acolvin@efunct.com> - 2014-03-28 23:08 +0000
            Re: catch and throw, was Is multi-level function return possible? Ivan Godard <ivan@ootbcomp.com> - 2014-03-28 18:24 -0700
              Re: catch and throw, was Is multi-level function return possible? Kaz Kylheku <kaz@kylheku.com> - 2014-03-29 02:47 +0000
                Re: catch and throw, was Is multi-level function return possible? Ivan Godard <ivan@ootbcomp.com> - 2014-03-28 21:32 -0700
              Re: catch and throw, was Is multi-level function return possible? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-29 03:38 +0000
                Re: precise and imprecise, was catch and throw, was Is multi-level function return possible? Ivan Godard <ivan@ootbcomp.com> - 2014-03-28 22:12 -0700
            Re: catch and throw, was Is multi-level function return possible? Kaz Kylheku <kaz@kylheku.com> - 2014-03-29 02:07 +0000
              Re: catch and throw, was Is multi-level function return possible? Alan Bawden <alan@scooby-doo.csail.mit.edu> - 2014-03-29 02:44 -0400
            Re: PL/I exceptions, was catch and throw, was Is multi-level function return possible? glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-03-29 02:40 +0000
              Re: PL/I exceptions "Robin Vowels" <robin51@dodo.com.au> - 2014-03-30 01:58 +1100
      Re: catch and throw, was Is multi-level function return possible? George Neuner <gneuner2@comcast.net> - 2014-03-28 03:52 -0400
  Re: Is multi-level function return possible? Louis Krupp <lkrupp@pssw.com> - 2014-03-11 15:16 -0600
  Re: Is multi-level function return possible? noitalmost <noitalmost@cox.net> - 2014-03-15 12:21 -0400

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