Article View: comp.lang.misc
Article #6034Re: Algol-style semicolons
From: Stephen Perelgut
Date: Wed, 21 Dec 1988 16:14
Date: Wed, 21 Dec 1988 16:14
42 lines
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2268 bytes
> |perelgut@turing.toronto.edu (Stephen Perelgut) writes:
> | Another method of handling semi-colons is to not have them. All you
> | need to do is terminate multi-part statements. For example:
> |
> | <Code fragment deleted>
> |
>
> NEVIN LIBER AT&T Bell Laboratories nevin1@ihlpb.ATT.COM (312) 979-4751
> Yes, but what do you do with statements that span more than one line?
> You still need a way of saying that an expression is to be continued on
> the next line (or that you don't need to continue a statement by
> use of a separator or terminator; this amounts to the same thing).
My example wasn't entirely clear on this point. Careful definition of a
language will allow statements to unambiguously extend across any arbitrary
amounts of whitespace including blanks, tabs, form-feeds and newlines. For
example, in the Turing programming language I might be acting dumb and write
a statement that looks like
if x
/ 7 >
12 then put "Hi there." else put
"It's not quite right" end
if
You might prefer to see this written as
if x/7 > 12 then
put "Hi there."
else
put "It's not quite right"
end if
The Turing language definition (and the various interpreters and compilers)
would treat both exactly the same. The paragraphing feature of the environment
supplied with the compilers would try to turn the first into a semblence of
the second.
One caveat, atomic elements cannot cross line boundaries so you can't split
a real number or a string literal across two lines. But you can break up
statements at any other point, even expressions
"This string contains the value" +
" of 7 + 5 as a string literal: " + intstr ( 7
+ 5)
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Path: arc1-ca.pugleaf.net!utzoo!attcan!utgpu!jarvis.csri.toronto.edu!csri.toronto.edu!perelgut From: perelgut@csri.toronto.edu (Stephen Perelgut) Newsgroups: comp.lang.misc Subject: Re: Algol-style semicolons Message-ID: <8812211614.AA10691@queen.csri.toronto.edu> Date: 21 Dec 88 16:14:14 GMT References: <1126@etive.ed.ac.uk> <208100002@s.cs.uiuc.edu> <868@mcrware.UUCP> <8008@aw.sei.cmu.edu> <GARY.88Dec15142623@milo.mcs.clarkson.edu> <88Dec16.100919est.4327@turing.toronto.edu> <9235@ihlpb.ATT.COM> Organization: University of Toronto, CSRI Lines: 42