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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: comp.lang.c
Subject: Re: Two replacements for unary +
Message-ID: <7939@utzoo.UUCP>
Date: Mon, 20-Apr-87 11:28:03 EST
Article-I.D.: utzoo.7939
Posted: Mon Apr 20 11:28:03 1987
Date-Received: Mon, 20-Apr-87 11:28:03 EST
References: <489@danews.ATT.COM> <2419@ulysses.homer.nj.att.com>, <1108@ius2.cs.cmu.edu>
Organization: U of Toronto Zoology
Lines: 20

>   Comment: the ANSI proposed unary + has the added semantic of enforcing
> 	   parenthesis ordering.
> 
>   Question: does the unary - have the added semantics of enforcing parenthesis
> 	    ordering?

In at least one draft it did; ugh.  Fortunately, it doesn't now.

>  If not, doesn't this add some non-orthogonality to the the unary + and -?

Well, yeah, but orthogonality is in the eye of the beholder.  The properties
of binary + and - are distinctly different (e.g. - is not associative), so
expecting orthogonality from the unary operators may be a bit much.

If you want real orthogonality, consider something that occurred to me some
years ago:  the "right" meaning of unary + is "absolute value"!  (Yes, I do
realize that there are practical reasons not to do this...)
-- 
"If you want PL/I, you know       Henry Spencer @ U of Toronto Zoology
where to find it." -- DMR         {allegra,ihnp4,decvax,pyramid}!utzoo!henry