Ulf Martin wrote:
I wonder how people (esp. at Pragma) currently deal with this. What happens if you have a ConTeXt doc from say 1997 that compiles into the resp. PDF with some ConTeXt version from that time but not today anymore? Which ConTeXt versions does one have to keep in order to be able to use such a document? (A good example for this kind of trouble seem to be the current issues with XeTeX, but I haven't followed this in detail -- but it kept me away from updating my ConTeXt installation since December...).
for projects where we use relatively new features (which evolve) we use frozen trees; actually some of this code is not even documented (simply no time; take synchronized graphics) with regards to commands and such ... context is just (supposed to be) downward compatible; even kind of obsolete is still there; with regards to different solutions to problems, we often provide control usign low level mode indicators concerning xetex ... keep in mind that there xetex is the moving target (changes/extensions in interface) and to some extend this was true for pdftex as well, but there we could silently adapt
Also remember that Knuth originally intended TeX to be an "eternal" formatting system (thus we have at least the option to expand all macros into plain TeX and keep that as the source file).
plain tex is just a format and unsuitable as expanded format well, i have some experimental code that dumps the expanded token list into a file; nu fun ... a 50 page moderately complex doc becomes some 25 meg -) but then, if the sole reason is to reprocess the doc ... just save the pdf file -)
This raises another question: is ConTeXt developed in an test driven way? I.e. are there test documents (including e.g. XML documents, bibligraphic references etc.) that have to pass comilation in order for changes to be published? If so, they would probably define a standard set of commands that could go into The ConTeXt Companion.
Sanjoy has set up an advanced test system ... so anything that you contribute can go in there Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com | www.pragma-pod.nl -----------------------------------------------------------------