On Fri, 1 Jul 2011 04:22:59 +0200 Philippe Verdy <[email protected]> wrote:
> 2011/7/1 Richard Wordingham <[email protected]>: > > Its main purpose is to indicate that a sequence of characters do > > not form a collating unit. However, if one is using a 'monospace' > > font to space 'letters' uniformly, i.e. to space collating > > sequences evenly, then I suggest it is the appropriate character. > Its main use is in fact to prevent reordering of otherwise canonically > equivalent sequences involving combining characters. I wonder if anyone has some statistics on the use of CGJ. Its revised intended use was to disrupt collating sequences, but you may be right about its most frequent use being to disrupt canonical reordering. A few years ago I concluded it wasn't yet safe to type the Welsh place name Llan͏gollen with CGJ. > As grapheme clusters should not be broken in the middle by collating > elements, A very Eurocentric view! You're misunderstanding me. The digraph should be encoded <C, H>, and accidental combinations <C, CGJ, H>. Therefore a 'monospace' font behaving as JFC wants should bunch <C, H> (a 'ligature') into one cell and display <C, CGJ, H> using two character cells. I am presuming that JFC would want ligatures and accidental combinations in normal proportional fonts to display the same. > > CGJ however MAY have a visual impact on the rendering (notably because > it helps fixing the relative order of sequences combining characters > with non-zero combining classes, exactly because these combining > characters may be positioned relatively to each other). But here I > don't see any problem od relative ordering. > In other words, <C,CGJ,H> or > <C,CGJ,APOS,CGJ,H> would not form the single collating elements really > needed for Breton. And I have never intentionally argued otherwise. Richard.
