Re: Borrow loop from other languages

Date	2026-03-20 03:18 +1100
Subject	Re: Borrow loop from other languages
Newsgroups	comp.lang.forth
References	<69bb591e$1@news.ausics.net> <10pg7kg$gr82$1@dont-email.me> <69bbcf87$1@news.ausics.net> <10pgsie$nrtk$1@dont-email.me>
From	dxf <dxforth@gmail.com>
Message-ID	<69bc21ec$1@news.ausics.net> (permalink)
Organization	Ausics - https://newsgroups.ausics.net

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On 20/03/2026 12:09 am, Lev wrote:
> ... 
> The LEAVE issue is one I hadn't considered.  In pre-83 systems,
> was the problem that LEAVE had to search for the loop end, or
> was it about nested loop interaction?  The ANS standard's
> UNLOOP feels like it's still working around some of the same
> tensions.

79-LEAVE simply set the index to the limit.  The programmer had
to ensure a path to LOOP for exit to occur.  In contrast 83-LEAVE
knows where to jump and can exit immediately.

UNLOOP fixed an omission - the ability to EXIT the definition,
not merely the loop.  Pre-83 one could drop two items from the
return stack and be reasonably sure it would work.  By 83 odds
were that it wouldn't.

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Borrow loop from other languages albert@spenarnc.xs4all.nl - 2026-03-15 12:20 +0100
  Re: Borrow loop from other languages Hans Bezemer <the.beez.speaks@gmail.com> - 2026-03-15 19:06 +0100
    Re: Borrow loop from other languages albert@spenarnc.xs4all.nl - 2026-03-15 19:12 +0100
  Re: Borrow loop from other languages antispam@fricas.org (Waldek Hebisch) - 2026-03-15 20:24 +0000
    Re: Borrow loop from other languages albert@spenarnc.xs4all.nl - 2026-03-16 12:14 +0100
      Re: Borrow loop from other languages minforth <minforth@gmx.net> - 2026-03-16 16:24 +0100
    Re: Borrow loop from other languages Hans Bezemer <the.beez.speaks@gmail.com> - 2026-03-18 16:11 +0100
      Re: Borrow loop from other languages thresh3@fastmail.com (Lev) - 2026-03-18 19:10 +0000
      Re: Borrow loop from other languages thresh3@fastmail.com (Lev) - 2026-03-18 19:10 +0000
      Re: Borrow loop from other languages thresh3@fastmail.com (Lev) - 2026-03-19 01:12 +0000
        Re: Borrow loop from other languages dxf <dxforth@gmail.com> - 2026-03-19 13:02 +1100
          Re: Borrow loop from other languages thresh3@fastmail.com (Lev) - 2026-03-19 07:12 +0000
            Re: Borrow loop from other languages dxf <dxforth@gmail.com> - 2026-03-19 21:27 +1100
              Re: Borrow loop from other languages thresh3@fastmail.com (Lev) - 2026-03-19 13:09 +0000
                Re: Borrow loop from other languages dxf <dxforth@gmail.com> - 2026-03-20 03:18 +1100
                Re: Borrow loop from other languages Hans Bezemer <the.beez.speaks@gmail.com> - 2026-03-19 18:31 +0100
                Re: Borrow loop from other languages thresh3@fastmail.com (Lev) - 2026-03-19 17:53 +0000
                Re: Borrow loop from other languages dxf <dxforth@gmail.com> - 2026-03-20 12:18 +1100
                Re: Borrow loop from other languages thresh3@fastmail.com (Lev) - 2026-03-19 13:35 -0500
                Re: Borrow loop from other languages thresh3@fastmail.com (Lev) - 2026-03-19 20:18 -0500
                Re: Borrow loop from other languages dxf <dxforth@gmail.com> - 2026-03-20 18:54 +1100

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