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From: zben@umd5.umd.edu (Ben Cranston)
Newsgroups: net.lang.c,net.lang.pascal
Subject: Re: Pascal vs C, again (was: Pascals Origins)
Message-ID: <1099@umd5.umd.edu>
Date: Tue, 22-Jul-86 19:20:42 EDT
Article-I.D.: umd5.1099
Posted: Tue Jul 22 19:20:42 1986
Date-Received: Wed, 23-Jul-86 08:45:38 EDT
References: <2222@brl-smoke.ARPA> <7014@boring.mcvax.UUCP> <3130@utcsri.UUCP> <5378@topaz.RUTGERS.EDU> <3142@utcsri.UUCP>
Reply-To: zben@umd5.umd.edu.UUCP (Ben Cranston)
Organization: University of Maryland, College Park
Lines: 32
Xref: watmath net.lang.c:10011 net.lang.pascal:592
Summary: Extended looping construct

In article <3142@utcsri.UUCP> greg@utcsri.UUCP (Gregory Smith) writes:

> As for the lack of break, it is a fact of life that loops do not always
> exit at the same point in the cycle as they start. Pascal ignores this.

Over the last ten years I have implemented several (interpretive) languages
with the extended repeat syntax:

   repeat
      (block 1)
   until condition
      (block 2)
   endrep

The idea was to allow the entry point and exit point of the loop to differ
without breaking the rule that a loop has only one exit point.

   repeat
      fooptr := readnextfoo(foofile)
   until (fooptr=0)
      haveyourwaywithfoo(fooptr)
   endrep

In C one would write:

   while ( 0 != (fooptr = readnextfoo(foofile)) )
      haveyourwaywithfoo(fooptr);

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