Hi all,
there seems to be a problem with the XeTeX engine and the "mapping:tex-text" feature for OpenType fonts. Try this:
---
\usetypescriptfile[type-minion] \usetypescript[minion][uc] \setupbodyfont[minion,13pt]
\starttext There is --- without any doubt --- a tiny problem. \stoptext
---
together with the attached typescript file. Unfortunately, "---" is not replaced by an em dash :-( Substituting works flawlessly for plain XeTeX examples. Of course, replacing "---" with the proper Unicode em dash in the above source solves the problem (by avoiding it).
Any hints as to what I've done wrong? what is mapping=tex-text supposed to do?
As far as I understood it's supposed to map TeX character sequences like "--" or "---" onto the corresponding Unicode characters. In fact these sequences aren't necessary at all, one could easily type the appropriate Unicode dashes in the source code. However, for the source editor I use a monospaced font which makes it rather hard to distinguish those proper Unicode dashes. I guess the character substitution that "mapping=tex-text" performs will extend to few other TeX sequences as well ... but definitely not for accented characters. Perhaps http://scripts.sil.org/cms/scripts/page.php? site_id=nrsi&item_id=xetex_faq#ligs might be helpful. Oliver