Re: catch and throw, was Is multi-level function return possible?

From	Kaz Kylheku <kaz@kylheku.com>
Newsgroups	comp.compilers
Subject	Re: catch and throw, was Is multi-level function return possible?
Date	2014-03-27 05:44 +0000
Organization	Aioe.org NNTP Server
Message-ID	<14-03-069@comp.compilers> (permalink)
References	<14-03-020@comp.compilers> <14-03-023@comp.compilers> <14-03-065@comp.compilers> <14-03-068@comp.compilers>

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On 2014-03-27, Rob Warnock <rpw3@rpw3.org> wrote:
> According to Gabriel and Steele in "The Evolution of Lisp"[1],
> Lisp 1.5 [early 1960s] had (ERRSET form), which:
>
>     ...evaluates *form* in a context in which errors do not terminate
>     the program or enter the debugger. If *form* does not cause an
>     error, ERRSET returns a singleton list of the value. If execution
>     of *form* does cause an error, the ERRSET form quietly returns NIL.
> ...

Before this, Lisp-2, around 1965 or 1966, already had TRY and EXIT,
which looked like a predecessor to catch, and a close relative of this
ERRSET, while also hinting at unwind-protect also (although, in
contrast, unwind-protect doesn't serve as the ultimate termination
point of a control transfer, but only a "pit stop").

TRY went something like this:

  (TRY <var> <protected-statemenet> <cleanup-statement>)

TRY evaluates <protected-statement>. If an (EXIT <val>) does not occur
in that evaluation, then when <protected-statement> terminates, the
TRY terminates and control passes to whatever form is next.

If an (EXIT <val>) operation occurs in <protected-statement>, then
variable <var> is bound to the value <val>, and <cleanup-statement> is
executed in scope of that variable. The exit is thereby intercepted,
and control continues with whatever is next after the TRY.

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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