IDC's versus Egyptian format controls

Ken Whistler via Unicode unicode at
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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