Newsgroups: comp.lang.c Path: utzoo!henry From: henry@utzoo.uucp (Henry Spencer) Subject: Re: Rearranging FP expressions Message-ID: <1988Sep27.174613.16697@utzoo.uucp> Organization: U of Toronto Zoology References: <4700017@m.cs.uiuc.edu> Date: Tue, 27 Sep 88 17:46:13 GMT In article <4700017@m.cs.uiuc.edu> wsmith@m.cs.uiuc.edu writes: >I realize this topic has been beat to death and its probably too late >for the ANSI C committee to do anything about it... Much too late, given that the matter has already been addressed: expressions must be evaluated as given unless rearrangement would yield the same results. ("The same" in a programming sense, not just in a mathematical sense.) >A proposed solution: > Expressions enclosed in double parentheses may not be rearranged, > all other expressions may be rearranged in "semantically valid" ways. Doesn't work too well. The trouble is that extra parentheses are common as a result of macro expansion. To do this sort of thing well, you really need another *kind* of parentheses. Such schemes have been proposed, but did not get accepted. -- NASA is into artificial | Henry Spencer at U of Toronto Zoology stupidity. - Jerry Pournelle | uunet!attcan!utzoo!henry henry@zoo.toronto.edu