From: Chris Gehlker Date: 2002-08-04T03:14:57+09:00 Subject: Re: Deprecation and Unicode On 8/3/02 10:25 AM, "Ned Konz" wrote: > On Saturday 03 August 2002 09:21 am, Danny van Bruggen wrote: >> 7: According to this point, Unicode has -much- more characters than >> 65536, so it needs more than two bytes. I haven't seen that >> mentioned here before. > > Actually, we've pretty much beat this to death in the past few days. > > My understanding from what I've heard (and I don't know much about > Unicode, so please correct me if I'm wrong), in layman's terms (i.e. > not standard-compliant language): > > Unicode is *defined* to be representable using 2-byte numbers. There > are provisions for using sequences of two (or more now?) of these > numbers to represent characters outside the basic 64K or so. There > are few applications that deal fully with these extended characters > ("surrogate pairs"?); Java (for instance) doesn't. > > In a program, representing Unicode by 2-byte numbers is probably ideal > unless you're very space-constrained (in which case UTF-8 is best) or > have to do a lot of character indexing *and* are using these > extension characters (in which case you might want to use a 4-byte > representation). I think you have it. Unicode is formally a 31 bit character set but the first 16 bits are called the "basic multilingual plane" (BMP) and were supposed to be adequate for representing most natural languages. Some of the characters in the BMP are combining or 'dead key' characters. What I have learned here is that either some or all of the Japanese think that it doesn't work for their language. It's not clear whether they think that more bytes are required or just that the existing standard doesn't assign them correctly. I'm ignoring the distinction between 'character' and 'glyph' because the discussion here has always made the distinction the same way as the Unicode folks do. -- Many individuals have, like uncut diamonds, shining qualities beneath a rough exterior. - Juvenal, poet (c. 60-140)