Where did you get the notion that space is not a base character? And base characters include those that are not control or format characters. Space is neither one.
The standard specifically states in a number of places that to exhibit a combining mark in isolation you use a space (or NBSP). Mark __________________________________ http://www.macchiato.com ► “Eppur si muove” ◄ ----- Original Message ----- From: "Peter Kirk" <[EMAIL PROTECTED]> To: "Jim Allan" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Tuesday, August 05, 2003 13:47 Subject: Re: Display of Isolated Nonspacing Marks (was Re: Questions on ZWNBS...) > On 05/08/2003 09:42, Jim Allan wrote: > > > Peter Kirk posted: > > > >> If I want to do this, should I explicitly encode a dotted circle, or > >> should I encode nothing and expect the font to generate the dotted > >> circle, as it often does? > > > > > > I think that practise of a font or application automaticaly inserting > > a dotted circle under an orphaned combining character is dubious > > compliant with Unicode specifications. > > > > ... > > > > > Thanks, Jim, for all this data, but now I am totally confused. Well, at > least it seems clear that if I want a dotted circle I should explicitly > encode it. But if I don't... > > Suppose for example I want to write a sentence like "In this language > the diacritic ^ may appear above the letters ...", but instead of ^ I > want to use a combining character, a regularly positioned centred above > the letter diacritic, which does not have a defined spacing variant. I > don't want a dotted circle. And I want it to be spaced as here, i.e. > with one space before the diacritic and one after it. It seems to me > that at one place in the standard I am told to encode space - combining > mark - space, for the combining mark will not combine with the space > because the space is not a base character; and in another place I am > implicitly told to encode space - space - combining mark - space, > because the second space acts as a carrier for the combining mark. > > I hope that wanting to display this correctly is not another place where > I "have stepped over the boundaries of what is reasonable to expect > plain text to convey", but that this too can be "grist for the Unicode > 5.0 mill to grind very finely" - both quotes from Ken Whistler earlier > today. And I think that if this issue is clarified it will also become > clear what should be done about string initial holam and alef etc. > > Perhaps a simple way ahead would be to define a new character something > like COMBINING MARK HOLDER with no glyph, which is defined specifically > for this purpose, is a base character and not a format character, and is > expected to be just as wide as is necessary to display the combining > mark. Then we could say that a spacing accent is equivalent (possibly > even canonically if made a composition exclusion?) to COMBINING MARK > HOLDER plus a non-spacing accent, and remove the misleading > compatibility equivalences to SPACE plus a non-spacing accent. > > -- > Peter Kirk > [EMAIL PROTECTED] > http://web.onetel.net.uk/~peterkirk/ > > > >
