William F. Hammond <[log in to unmask]> on Wed, 21 Oct 1998 09:01:47 -0400 wrote: > But my original question was motivated by several lines from > "ltx3info.tex" and my wondering whether these lines were durable > for the LaTeX-3 future. > > Here are clips of a "newenvironment" and a "newcommand": > > %%%%% clip > \newenvironment{citations}{% > \list{}{% > \renewcommand{\makelabel}[1]{\normalfont\itshape ##1}% > }% > }{% > \endlist > } > %%%%% clip > \newcommand{\AmSLaTeX}{$\mathcal A$\lower.4ex\hbox{$\!\mathcal > M\!$}$\mathcal S$-\LaTeX} > %%%%% endclips > > (I do not see why "citations" could not have been done entirely in > Lamport LaTeX. (I am unclear what "list" and "endlist" are.)) A LaTeX environment "foo" is basically implemented as a pair of commands "\foo" and "\endfoo". The construct \begin{foo} ... \end{foo} will be translated to something like \begingroup \foo ... \endfoo \endgroup plus some extra code to check whether such an environment is defined at all and whether the names given as arguments to \begin and \end match each other. Many of LaTeX's environments (e.g., enumerate, quotation, description, verse) are based on the "list" environment (or its cousin "trivlist"); i.e., in the above definition \begin{list} ... \end{list} could've been used as well---the only differences would have been an extra (redundant) level of grouping and some performance overhead. > In the "AmSLaTeX" macro I believe that "lower" and "hbox" are > ordinary TeX. Yupp. These are TeX primitives (built-in, not macros) --- unless somebody comes along and redefines them, of course. > Will this usage survive? Probably not. According to the demos/preview of LaTeX3 published last spring (1), *lots* of things are going to change. (The TeXbook may well become useless for us humble package writers ...) (1) CTAN:macros/latex/packages/expl3/ Hubert Gaesslein <[log in to unmask]>