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From: faustus@ucbcad.BERKELEY.EDU (Wayne A. Christopher)
Newsgroups: net.lang
Subject: Re: ReExplanation of (x<y<z)
Message-ID: <1091@ucbcad.BERKELEY.EDU>
Date: Wed, 15-Oct-86 16:41:49 EDT
Article-I.D.: ucbcad.1091
Posted: Wed Oct 15 16:41:49 1986
Date-Received: Wed, 15-Oct-86 21:53:22 EDT
References: <7871DMB@PSUVMA>
Organization: CAD Group, U.C. Berkeley
Lines: 15

In article <7871DMB@PSUVMA>, dmb@psuvm.bitnet.UUCP writes:
>    Sorry I guess the question wasn't which languages support it, but why
> most of the major ones don't?

I think it is a matter of clean expression semantics -- 'x < y' has a value
which is a boolean, and so '(x < y) < z' doesn't mean what it should mean.
Another (tertiary) operator would do the job, as would

#define between(x, y, z) (((x) < (y)) && ((y) < (z)))

but I imagine that for the languages that do allow x < y < z, a large reason
why they aren't 'major' is that they are careless of semantic clarity and
orthagonality.

	Wayne