Than you Hans!
My plan is simply to use the output of a sagemath run in this way. A run
should produce
several files containing TeX code. I only wanted to shorten the
\startbuffer \input ... \stopbuffer
sequence. Maybe this (including sagemath output) could be done differently,
but this was
the first (and only ;-)) idea I came up with.

kind regards
Erik

On Wed, Mar 30, 2016 at 10:11 AM, Hans Hagen <pragma@wxs.nl> wrote:

> On 3/30/2016 9:27 AM, Erik Margraf wrote:
>
>> Dear List,
>>
>> please help me with my problem here ....
>>
>> I - probably naively - tried the following:
>> ------------------------
>>
>> \starttext
>>
>>
>> \def\Buffer#1#2
>>
>> {
>>
>> \startbuffer[#1]
>>
>> \input #2
>>
>> \stopbuffer
>>
>> }
>>
>> \Buffer{bla}{knuth}
>>
>>
>> \stoptext
>>
>> -------------------------
>>
>>
>> Context gives me the following error on this:
>>
>>
>> tex error > tex error on line 9 in file
>> C:/Users/emargraf/Documents/buffer.tex: ! Undefined control sequence
>>
>>
>>
>> \Buffer ...startbuffer [#1] \input #2 \stopbuffer
>>
>> l.9 \Buffer{bla}{knuth}
>>
>
> \startbuffer .. \stopbuffer is parsed special
>
> so use:
>
> \def\Buffer#1#2
>   {\setbuffer[#1]{\input #2\relax}}
>
> \Buffer{bla}{knuth}
>
> but i'm not sure what you gain here as it will still input tufte each time
>
> Hans
>
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