Character/column confusion in Mule [was: Are long line caches useful?]

(Sorry, I don't remember if -beta is gated to -mule, but I believe not.) Hrvoje> Do you think this particular FSF Emacs feature is truly Hrvoje> useful? As long as I'm here: No. In view of the following, even if you wanted to, you probably ought to wait until some other stuff is settled: (from the FSF's NEWS, I guess?) *** Faster processing of buffers with long lines Normally, the line-motion functions work by scanning the buffer for newlines. Columnar operations (like `move-to-column' and `compute-motion') also work by scanning the buffer, summing character widths as they go. ~~~~~~ The FSF's implementation of Mule has historically checked column widths (on a Japanese TTY, ASCII characters traditionally take up 1 column, an ideographic character 2) for things like `format'. We don't. On the other hand, our `what-cursor-position' does. Unfortunately, I don't know yet which XEmacs functions are like `format' and which like `what-cursor-position'. (But now that I know they're different, the fact that `format' doesn't do so is probably a bug. Sorry Olivier.) I guess I'll have to start looking, but I don't know where. Help! Which should we do? Use the (bogus) assumption, which may in fact not apply to Korean or Chinese (anybody know?), that Western characters are (integral) 1 column and Oriental ideographs are 2 columns wide ... ornot? This isn't even true for sure in a TTY; at many sizes in a kterm, even with fixed fonts, ideograph width is not quite an integral multiple of Latin character width. I don't know if it's relevant, but I seem to recall some Japanese printers that allow compression of the ideographs to 3/2 the width of Latin characters. There may even be terminals like that. On the other hand, it is a very useful assumption in most Japanese environments, and even with proportional fonts produces tables that are moderately readable. I guess it would also be useful for Chinese and Korean environments, but I have no experience (they may, unlike the Japanese, normally use the same width font for Latin as for ideographic characters). -- University of Tsukuba Tennodai 1-1-1 Tsukuba 305-8573 JAPAN Institute of Policy and Planning Sciences Tel/fax: +1 (298) 53-5091