[latex3-commits] [git/LaTeX3-latex3-latex2e] develop: First draft on primitive requirements (d5138808)

[Joseph Wright]

Repository : https://github.com/latex3/latex2e
On branch  : develop
Link       : https://github.com/latex3/latex2e/commit/d5138808c8c409d1ff0902c3732d3624499ea6b2

>---------------------------------------------------------------

commit d5138808c8c409d1ff0902c3732d3624499ea6b2
Author: Joseph Wright <joseph.wright at morningstar2.co.uk>
Date:   Tue Oct 15 10:33:12 2019 +0100

    First draft on primitive requirements
    
    I've not included the RNG or timing functions,
    and only the file size function: we could require
    the 'full set' here as adding one or two is not
    really different from adding all of them.
    
    Including \expanded is the most tricky, perhaps,
    as pdfTeX only got it in TL'19.


>---------------------------------------------------------------

d5138808c8c409d1ff0902c3732d3624499ea6b2
 base/doc/ltnews31.tex | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/base/doc/ltnews31.tex b/base/doc/ltnews31.tex
index 2a8eeb18..a2835f91 100644
--- a/base/doc/ltnews31.tex
+++ b/base/doc/ltnews31.tex
@@ -136,6 +136,28 @@
 This document is under construction \ldots
 
 
+\section{Primitive requirements}
+
+Since the finalisation of \eTeX{} in 1999, a number of additional `utility'
+primitives have been added to \pdfTeX{}. Several of these are broadly useful
+and have been requirements for \pkg{expl3} for some time, most notably
+\cs{pdfstrcmp}. Over time, a common set of these `post-\eTeX{}' primitives have
+been incorporated into \XeTeX{} and (u)p-\TeX{}; they were available in
+\LuaTeX{} already.
+
+A number of the additional primitives are needed to support new or improved
+functionality in \LaTeX{}. This is seen for example in improved UTF-8 handling,
+which uses \cs{ifincsname}. The following primitive functionality (which in
+\LuaTeX{} may be achieved using Lua code) will therefore be \emph{required} by
+the \LaTeX{} kernel after [INSERT DATE HERE]:
+\begin{itemize}
+  \item \cs{ifincsname}
+  \item \cs{pdfstrcmp}
+  \item \cs{pdffilesize}
+  \item \cs{expanded}
+  \item \cs{Uchar}, \cs{Ucharcat} (Unicode engines only)
+\end{itemize}
+
 \section{Experiences with the \LaTeX\texttt{-dev} formats}
 
 \emph{write}