Article View: comp.lang.misc
Article #5459Re: Block Closure
From: David Collier-Brown
Date: Sat, 23 Apr 1988 16:45
Date: Sat, 23 Apr 1988 16:45
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In article <757@l.cc.purdue.edu> cik@l.cc.purdue.edu (Herman Rubin) writes:
>I find both of these methods at times easy to follow, and at times hard to
>follow. There is also the problem of a multiple break.
>[...]
> break LABEL
> endall LABEL
Well, both have been tried, with mixed results. One could label
begin-end blocks in PL/1, and add either the block label of the name
of the control structure between the "end" and its ";". At least
two compilers used this to double-check block nesting and produce
warning messages.
Similarly, some PL/1 variants (and my memory is fuzzy here...)
allowed a leave <label> statement which exited a named block. This
may have been part of the ANSI standard, but that was too long ago.
Labelled blocks and "endall" existed in BCPL, but were very
little-used. It was not obvious whether it was because it was
non-traditional or buggy, but is usually remembered in terms of the
claim that it lead to making block-balancing errors.
--
David Collier-Brown. {mnetor yunexus utgpu}!geac!daveb
Geac Computers International Inc., | Computer Science loses its
350 Steelcase Road,Markham, Ontario, | memory (if not its mind)
CANADA, L3R 1B3 (416) 475-0525 x3279 | every 6 months.
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Path: arc1-ca.pugleaf.net!utzoo!yunexus!geac!daveb From: daveb@geac.UUCP (David Collier-Brown) Newsgroups: comp.lang.misc,comp.lang.c Subject: Re: Block Closure Summary: industry experience Message-ID: <2638@geac.UUCP> Date: 23 Apr 88 16:45:29 GMT Article-I.D.: geac.2638 Posted: Sat Apr 23 12:45:29 1988 References: <2853@enea.se> <2400014@otter.hple.hp.com> <918@rlgvax.UUCP> <Apr.18.19.01.07.1988.13299@porthos.rutgers.edu> <757@l.cc.purdue.edu> Reply-To: daveb@geac.UUCP (David Collier-Brown) Organization: The Geac History Department. Lines: 25