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From: broman@PEANUTS.NOSC.MIL (Vincent Broman)
Newsgroups: comp.lang.modula2
Subject: What is the use of tag fields and case labels in records ?
Message-ID: <8901252027.AA24793@cod.nosc.mil>
Date: 25 Jan 89 20:27:26 GMT
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Good usage of variant records requires you do your own
run-time checking of the tag.  Essentially what is required
is that references to fields that vary occur only inside
CASE tag statements.  As a relaxation to this rule one can
infer the value of the tag from other parts of the program
state and omit the CASE test, but this is error prone.
Variant records without tag fields are just a special
case of this relaxed usage.

Vincent Broman,  code 632, Naval Ocean Systems Center, San Diego, CA 92152, USA
Phone: +1 619 553 1641    Internet: broman@nosc.mil   Uucp: sdcsvax!nosc!broman