[lltx] \expanded: a pdfTeX primitive?

[Paul Isambert]

Le 27/05/2011 12:17, Manuel Pégourié-Gonnard a écrit :
> Hi,
>
> According to the manual (and tex.extraprimitives), \expanded is a pdfTeX
> primitive. However,
>
> % pdftex -ini '\show\expanded \end'
> This is pdfTeX, Version 3.1415926-1.40.11 (TeX Live 2010) (INITEX)
>   restricted \write18 enabled.
>> \expanded=undefined.
> <*>  \show\expanded
>                     \end
> ?
> No pages of output.
> Transcript written on texput.log.
>
> Also, I can find no mention of \expanded in the pdfTeX manual. Am I missing
> something?

If I remember correctly, \expanded is a pdfTeX primitive... that never 
made it to pdfTeX, hence its absence in the manual.
And it's meaning is to expand completely its argument. E.g.:

\def\foo{\bar}
\def\bar{bla}
\immediate\write17{\unexpanded\expandafter{\expanded{\foo\foo}}}

prints "blabla".

Best,
Paul