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From: chl@r1.uucp (Charles Lindsey)
Newsgroups: comp.lang.misc
Subject: Re: Algol-style semicolons (was Re: What makes a language successful)
Keywords: semicolons, statements, end
Message-ID: <5319@ux.cs.man.ac.uk>
Date: 16 Dec 88 11:04:38 GMT
References: <1126@etive.ed.ac.uk> <208100002@s.cs.uiuc.edu> <868@mcrware.UUCP>
Sender: news@ux.cs.man.ac.uk
Reply-To: chl@r1.UUCP (Charles Lindsey)
Organization: University of Manchester, UK
Lines: 51

In article <208100002@s.cs.uiuc.edu> carroll@s.cs.uiuc.edu (Alan Carroll) writes:
>/* Written 10:10 am  Dec  4, 1988 by bct@lfcs.ed.ac.uk in s.cs.uiuc.edu:comp.lang.misc */
>/* ---------- "Re: What makes a language successfu" ---------- */
> Another sad point is that even died-in-the wool Algol 68 people like Charles
>Lindsey have drifted into putting semi-colons before ENDs.

Time for "died-in-the-wool Charles Lindsey" to say what he really does.

>I always thought that the 'no ; before END' part of PASCAL was one of the worst
>'features' of the language.

First let us understand the rules:
	PASCAL has a dummy-statement, so ';' before END is OK
	ALGOL 68 has no dummy-statement, so ';' before END is forbidden

In article <868@mcrware.UUCP> jejones@mcrware.UUCP (James Jones) writes:
>I never could understand what the difficulty is with Algol-style semicolons.
>...  In Algol, semicolons *separate* statements. ...

Yes, but Carroll still has a point

>... I can't count how many times I had to recompile
>because I had added a statement before an END and forgotten to put a ; on
>the *previous* statement.

Here is what Charles Lindsey actually does:
When writing in PASCAL, I always put a ';' at the end of each
	statement, even before an END, for the reason Carroll gave.
When writing in ALGOL 68, I always put a ';' BEFORE each statement (except the
	first). Here is the example that started all the fuss (so far as I
	remember it).

	BEGIN LOC INT i := 0, j := 1
	  ;   LOC REF INT ptr := i
	  ;   ptr := j
	  ;   print(i)
	END

>{James Jones again} "end" and "begin" serve the same purpose as paren-
>theses, and indeed, Algol 68 makes this even more obvious by allowing the
>use of parentheses in place of begin and end if one wishes.

Indeed, and it looks even better (and is easier to type) this way:

	( LOC INT i := 0, j := 1
	; LOC REF INT ptr := i
	; ptr := j
	; print(i)
	)

Charles Lindsey	chl@ux.cs.man.ac.uk