[Rd] 1954 from NA

Adrian Dușa du@@@@dr|@n @end|ng |rom gm@||@com
Mon May 24 17:15:46 CEST 2021


On Mon, May 24, 2021 at 5:47 PM Gabriel Becker <gabembecker using gmail.com>
wrote:

> Hi Adrian,
>
> I had the same thought as Luke. It is possible that you can develop an
> ALTREP that carries around the tagging information you're looking for in a
> way that is more persistent (in some cases) than R-level attributes and
> more hidden than additional user-visible columns.
>
> The downsides to this, of course, is that you'll in some sense be doing
> the same "extra vector for each vector you want tagged NA-s within" under
> the hood, and that only custom machinery you write will recognize things as
> something other than bog-standard NAs/NaNs.  You'll also have some problems
> with the fact that data in ALTREPs isn't currently modifiable without
> losing ALTREPness. That said, ALTREPs are allowed to carry around arbitrary
> persistent information with them, so from that perspective making an ALTREP
> that carries around a "meaning of my NAs" vector of tags in its metadata
> would be pretty straightforward.
>

Oh... now that is extremely interesting.
It is the first time I came across the ALTREP concept, so I need to study
the way it works before saying anything, but definitely something to
consider.

Thanks so much for the pointer,
Adrian

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