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From: mat@hou5d.UUCP
Newsgroups: net.lang.c
Subject: Unions w/o struct a crock? NO!
Message-ID: <897@hou5d.UUCP>
Date: Mon, 9-Apr-84 15:19:09 EST
Article-I.D.: hou5d.897
Posted: Mon Apr  9 15:19:09 1984
Date-Received: Wed, 11-Apr-84 04:16:31 EST
Organization: AT&T Information Systems Laboratories, Holmdel, NJ
Lines: 19

Are unions outside of structs a crock?  Well, there is one important
situation where they are used.  The system II and system V YACC parsers
allow arbitrary objects to be passed on the value stack;  consistancy
is insured by declarations of types represented by terminals and by a
rather weird syntax.  This is only feasible with unions and the unions
(unlike variant records) need no discriminant, so there is no surrounding
struct.

Why, oh why saddle a useful construct like the union with a problem-dependent
restriction like discriminants?  Why go out of your way to make something
simple into something troublesome by adding combersome restrictions that are
not universally necessary?

-- 

					from Mole End
					Mark Terribile
		     (scrape..dig)	hou5d!mat
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