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Article #411help with vgrindefs
From: Daniel M. Berry
Date: Fri, 28 Dec 1984 21:54
Date: Fri, 28 Dec 1984 21:54
27 lines
1443 bytes
1443 bytes
There is something puzzling about the form of the vgrindefs:
Specifically consider:
:pb=(^\d?procedure|function|program\d\p\d|\(|;|\:)|(=\d?record\d):\
from the pascal definition.
Why are there no parentheses around (procedure|....|program)?
It appears to me that the quoted line says that a procedure begins with
any one of the following
1.new-line,optional-delimiter,"procedure"
2."function"
3."program",delimiter,identifier,delimiter
4."("
5.";"
6.":"
because of the way the parens surround the ors.
But then why is the whole line structured as
(.....)|(.....)
?
I would think that the correct line would be...
:pb=(^\d?(procedure|function|program\d\p\d|\(|;|\:))|(=\d?record\d):\
^ ^
Can someone explain the precedence rules?
Thanks
Dan Berry
Happy New Year
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dberry@ucla-cs
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site sdcrdcf.UUCP Path: arc1-ca.pugleaf.net!utzoo!decvax!ittvax!dcdwest!sdcsvax!sdcrdcf!dberry From: dberry@sdcrdcf.UUCP (Daniel M. Berry) Newsgroups: net.text Subject: help with vgrindefs Message-ID: <1628@sdcrdcf.UUCP> Date: Fri, 28-Dec-84 16:54:05 EST Article-I.D.: sdcrdcf.1628 Posted: Fri Dec 28 16:54:05 1984 Date-Received: Sat, 29-Dec-84 10:11:07 EST Distribution: net Organization: System Development Corp. R+D, Santa Monica Lines: 27