From: Christopher Browne Date: 2002-09-11T01:54:43+09:00 Subject: Re: Larry Wall's comments on Ruby Centuries ago, Nostradamus foresaw when Giuseppe Bilotta would write: > nico wrote: >> On September 10, 2002 04:38 am, Gavin Sinclair wrote: >> >> > I'm not convinced that it's unnatural. We don't know the types of a and >> > b, and for some objects a and b, a + b != b + a. >> > >> > I'm interested what you think the alternative is, or an argument against >> > the above, and how you would like to see a + b defined in Ruby. >> > >> > Gavin >> >> I find that highly unnatural because we've been learning since grade school >> that a + b = b + a. >> >> If the objects don't satisfy that property they should be using a different >> symbol. > > No way. For example, product is commutative only up to complex > numbers. If you move on to quaternions, you get a noncommutative > product. And as for noncommutative sum ... think for example about > strings. "a" + "b" != "b" + "a" In Group Theory, the whole _point_ is to come up with addition and multiplication operators to define a "group." There are groups in which these operators behave in the 'grade eight' fashion; there are groups in which they most certainly do NOT behave in that fashion. -- (concatenate 'string "cbbrowne" "@ntlug.org") http://cbbrowne.com/info/sgml.html Rules of the Evil Overlord #190. "If my mad scientist/wizard tells me he has almost perfected my Superweapon but it still needs more testing, I will wait for him to complete the tests. No one ever conquered the world using a beta version."