[Bug 13502] Text run starting with composing character should be valid

http://www.w3.org/Bugs/Public/show_bug.cgi?id=13502

--- Comment #24 from Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no> 2011-10-02 15:09:59 UTC ---
(In reply to comment #22)

> Rationale: I spoke with Mark Davis, who informed me that I was wrong. Unicode
> does intend to allow combining characters to be styled differently.

OK. This seems to be correct. For documentation, her are some quotes from
Unicode 6.0:

]]
5.11 Editing and Selection
   [ snip ]
Nonlinear Boundaries. Use of nonlinear boundaries divides any stacked element
into parts. For example, picking a point halfway across a lam + meem ligature
can represent the division between the characters. One can either allow
highlighting with multiple rectangles or use another method such as coloring
the individual characters.
   [ snip ]
In most editing systems, the code point is the smallest addressable item, so
the selection and assignment of properties (such as font, color, letterspacing,
and so on) cannot be done on any finer basis than the code point. Thus the
accent on an “e” could not be colored dif- ferently than the base in a
precomposed character, although it could be colored differently if the text
were stored internally in a decomposed form.
[[

]]
9.1 Devanagari
   [ snip ]
In Vedic manuscripts the tonal mark (that is, the horizontal bar, upward curve
and down- ward curve) appears in colored ink, while the two dots of the visarga
appear in black ink. The characters for accents can be represented using
separate characters, to make it easier for color information to be maintained
by means of markup or other higher-level proto- cols.
[[

[[
15.11 Western Musical Symbols
   [ snip ]
In some contexts— particularly for applications in early music—note heads,
stems, flags, and other associated symbols may need to be rendered in different
colors—for example, red.
]]

-- 
Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug.

Received on Sunday, 2 October 2011 15:10:02 UTC