IDC's versus Egyptian format controls
Ken Whistler via Unicode
unicode at unicode.org
Fri Feb 16 10:41:47 CST 2018
On 2/16/2018 8:22 AM, Ken Whistler wrote:
> The Egyptian quadrat controls, on the other hand, are full-fledged
> Unicode format controls.
One more point of distinction: The (gc=So) IDC's follow a syntax that
uses Polish notation order for the descriptive operators (inherited from
the intended use in GB 18030, where these came from in the first place).
That order minimizes ambiguity of representation without requiring
bracketing, but it has the disadvantage of being hard for humans to
interpret easily in complicated cases.
The Egyptian format controls use an infix notation, instead. That
follows current Egyptologists' practice of representing quadrats with
MdC conventions. It is also a better order for the layout engine
processing. The disadvantage is that it requires a bracketing notation
to deal with ambiguities of operator precedence in complicated cases.
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