Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!ucsd!sdcsvax!ucsdhub!hp-sdd!hplabs!hpda!hpcupt1!hpcuhb!hpcllla!hpcllz2!walter
From: walter@hpcllz2.HP.COM (Walter Murray)
Newsgroups: comp.std.c
Subject: Question about regrouping of operands
Message-ID: <16490001@hpcllz2.HP.COM>
Date: 11 May 88 17:25:10 GMT
Organization: HP NSG/ISD Computer Language Lab
Lines: 17

Under the proposed C standard, a conforming implementation is
no longer free to disregard parentheses in evaluating an
expression.  At least, the results must be _as_if_ parentheses
were honored.  The Rationale explains that this brings C into
accord with FORTRAN and other languages.

Actually, as I read the proposed standard, ANSI C would seem to
be _more_strict_ than FORTRAN.  For example, FORTRAN requires the
expression X+Y+Z to be _interpreted_ as (X+Y)+Z, but explicitly
permits it to be _evaluated_ as X+(Y+Z), even though the results could
be different.  The proposed C standard seems to require that, in
the absence of parentheses, both the interpretation and the 
evaluation be done left-to-right.  Thus, in C, the expression
X+Y+Z would have to be evaluated as (X+Y)+Z.

Any thoughts?  Am I interpreting the proposed standard correctly?

		   -- Walter Murray