At 2002-10-16 17:37 -0400, John Cowan wrote:
> Tim Bray scripsit:
> 
>  > In the general case where you want to wrap up weird bits of binary
>  > gibberish to control hardware, why don't you just base64 it and not have
>  > to worry about which of them are magic C0 Controls and which aren't...
> 
> Well, that's a question.  Are the terminal control sequences characters or
> octets?  On the face of X3.64 (I forget the ISO number), they are octets,
> but people think of "move up" as ESC [ A, not 1/11 5/11 4/1 (in the
> poor-mans-hex used by the standard).

Are you thinking of ISO-2022?  Using escape sequences to fill G0 through G3 
with 94, 96, 94*94 and 96*96, and then escape or shifting sequences to 
single shift or lock shift G0 through G3 into GL and GR?

When I think of those escape sequences I think of representations of 
characters from different character sets being loaded into each of G0 
through G3, which means to me it is a character encoding issue addressed in 
the XML declaration.  Processing applications would see the Unicode 
characters after a character decoder figured out from the registered escape 
sequences the character sets and corresponding characters in the stream.

I don't think anything need be "solved" at the character level of XML ... 
ISO-2022 controls to me are just that ... controls ... not characters.

................. Ken

p.s. Anyone else out there work with NAPLPS X3.110(ANSI)/T500(CSA) that was 
based on ISO-2022?


--
G. Ken Holman               mailto:gkholman@[...].com
Crane Softwrights Ltd.        http://www.CraneSoftwrights.com/x/
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Next public training:          2002-12-08,2003-02-03,06,03-03,06


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