# [luatex] New \pdf... primitives

David Carlisle d.p.carlisle at gmail.com
Tue Nov 17 01:35:03 CET 2015

```On 16 November 2015 at 23:49, Hans Hagen <pragma at wxs.nl> wrote:
> On 11/16/2015 11:39 PM, Joseph Wright wrote:
>>
>> Hello all,
>>
>> Setting up some tests to work with the v0.85 code, I notice that the
>> suggestion in the manual
>>
>>    \edef\pdfhorigin{\pdfvariable horigin}
>>
>> yields with \show\pdfhorigin
>>
>>    \pdf_horigin=\pdf_horigin
>>
>> which is accessible using \csname or catcode changes. That seems odd
>> based on the fact this change has been made at all: is this a passing bug?
>
>
> indeed deep down counters are used for a few (but not defined in the usual
> range); the main reason is to make sure that (at least for now) old code
> that expects a counter still works ok (as i have no clue how abstract macro
> package interfaces to this pdf stuff are) ... so maybe later that low level
> thingie will go)
>
> anyway, the split in the three categories made it possible to nicely regroup
> the related code (so that we have a cleaner core code base, a bit more more
> close to original tex, not mixed with backend related checks and primitives
> in inconsistent ways)
>
> Hans
>
>
>

related to this, trying to work out the syntax of \pdfvariable (which
is not described in the manual)

it seems to be an expandable command with syntax

\pdfvariable <optional spaces> {fixed list of keywords}

the error handling seems a bit aggressive though, while testing if it
took <filler> rather than <optional spaces> I tried

\edef\test{\pdfvariable\relax horigin}
which produces

! I can't go on meeting you like this.