Re: [Cbor] typed arrays for complex numbers

Carsten Bormann <cabo@tzi.org> Fri, 12 July 2019 00:23 UTC

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From: Carsten Bormann <cabo@tzi.org>
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Date: Fri, 12 Jul 2019 02:23:23 +0200
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Subject: Re: [Cbor] typed arrays for complex numbers
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On Jul 12, 2019, at 01:24, Gregory Allen <gallen@arlut.utexas.edu>; wrote:
> 
> I could imaging a “complex” tag, that’s a modifier for a dataType, so that one could do:
> 
>    multi-dim([dim, complex(ta-float32le(bstr)) ])
> 
> However, that doesn’t scale well to having several different compound types such as those mentioned above.

Well, it requires a new tag for each of these compound types, but if these are indeed different types, then tags are cheap (as long as they don’t have to come out of the 1+1 space :-).

So if this helps, we could indeed define tags (for complex, quaternion, octonions, sedenions, RGB, RGBA) that extract groups of 2, 4, 8, 16, 3, 4 elements out of an array (tagged or classical CBOR).
(Well, RGB is a bit weird, because there are so many color spaces.  Maybe just have tags for three- and four-dimensional color spaces.)
Alternatively, supplying the group size separately maybe can do all of these at omce, but then cannot distinguish quaternions from RGBA or CMYK.

Grüße, Carsten