Patches item #466, was opened at 2006-01-07 17:22 You can respond by visiting: http://sarovar.org/tracker/?func=detail&atid=495&aid=466&group_id=106 Category: Primitives Group: v1.40.0 Status: Open Resolution: Accepted Priority: 4 Submitted By: Taco Hoekwater (taco) Assigned to: Martin Schröder (oneiros) Summary: \primitive and \ifprimitive Initial Comment: This patch implements two new primitives: \primitive \par This will run the 'primitive' command \par, even if it has been re- or undefined in the meantime. \primitive is not expandable, because it may be asked to execute unexpandable primitives as well as expandable ones. If you supply a nonexistant primitive, it will be ignored (no error is raised). The second primitive is a new type of \if: \ifprimitive \par ... \else .. \fi returns true if the current meaning of \par is the 'primitive' command \par. The patch is against alpha-20051226, i hope that is not too old (?). I expect to do at least one minor update during the beta cycle, after the pdftex code is flattened. It was quite a struggle to make this change file work ok, and as a result, there are a few ugly web hacks. ---------------------------------------------------------------------- Comment By: Bernd Raichle (bernd) Date: 2006-02-13 17:40 Message: Logged In: YES user_id=3344 IMHO it would be better to rephrase the above to (and change the implementation accordingly :-(): <quote mode="changed"> \primitive is expandable, because it may asked to execute expandable primitives as well as unexpandable ones. \primitive<cs> will expand to one token, the original TeX primitive. This token will then be processed further as usual. </quote> If \primitive is left unexpandable, a lot of programming techniques seems to be unavailable, e.g., all redefined expandable primitives in expandable-only context. Or any assignment to the get the original primitive, like \edef\orignumber{\expandafter\noexpand\primitive\number} \expandafter\let\expandafter\orignumber\primitive\number Sidenote: The new \primitive seems to implement a subset of a full-blown namespace mechanism. If (pdf)TeX would have namespaces, one simply has to access the appropriate token within the "primitive" namespace (e.g. \primitive::number to access the original \number primitive, assuming the notation \<namespace>::<csname>). How about choosing an appropriate namespace mechanism for (pdf)TeX and implementing it instead? ---------------------------------------------------------------------- You can respond by visiting: http://sarovar.org/tracker/?func=detail&atid=495&aid=466&group_id=106