Xref: utzoo comp.lang.misc:1488 comp.lang.c:9552
Path: 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

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) 
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