New primitives prefixing policy for LuaTeX-based formats.

git-svn-id: svn://tug.org/texlive/trunk@15400 c570f23f-e606-0410-a88d-b1316a301751

5 files changed, 74 insertions, 27 deletions

diff --git a/Master/texmf-dist/tex/latex/latexconfig/dvilualatex.ini b/Master/texmf-dist/tex/latex/latexconfig/dvilualatex.ini
index a35581d9531..f0c47ffaeec 100644
--- a/Master/texmf-dist/tex/latex/latexconfig/dvilualatex.ini
+++ b/Master/texmf-dist/tex/latex/latexconfig/dvilualatex.ini
@@ -1,7 +1,7 @@
 % $Id$
 % Karl Berry, originally written 2008. public domain.
 %
-\input luatexiniconfig.tex
+\input lualatexiniconfig.tex
 \input pdftexconfig
 \pdfoutput=0  % dvi output by default
 %
diff --git a/Master/texmf-dist/tex/latex/latexconfig/lualatex.ini b/Master/texmf-dist/tex/latex/latexconfig/lualatex.ini
index 00404d7e71d..225bd4ced4f 100644
--- a/Master/texmf-dist/tex/latex/latexconfig/lualatex.ini
+++ b/Master/texmf-dist/tex/latex/latexconfig/lualatex.ini
@@ -1,6 +1,6 @@
 % $Id$
 % Karl Berry, originally written 2008. public domain.
-\input luatexiniconfig.tex
+\input lualatexiniconfig.tex
 \input pdftexconfig.tex
 % pdf output by default.
 \scrollmode
diff --git a/Master/texmf/tex/generic/config/lualatexiniconfig.tex b/Master/texmf/tex/generic/config/lualatexiniconfig.tex
new file mode 100644
index 00000000000..2061c9fe54d
--- /dev/null
+++ b/Master/texmf/tex/generic/config/lualatexiniconfig.tex
@@ -0,0 +1,60 @@
+% $Id$
+% Enable and prefix LuaTeX primitives for LaTeX-based formats
+% Assumes LuaTeX 0.39.x or greater.
+% Manuel Pégourié-Gonnard, 2009. Public domain.
+\begingroup
+\catcode`\{=1
+\catcode`\}=2
+\directlua{
+  % etex and pdftex primitives are enabled without prefixing
+  tex.enableprimitives('', 
+    tex.extraprimitives('etex', 'pdftex'))
+  % other primitives are prefixed with luatex (see below)
+  tex.enableprimitives('luatex', 
+    tex.extraprimitives('core', 'omega', 'aleph', 'luatex'))
+  }
+\endgroup
+\endinput
+
+% Rationale for primitives prefixing.
+%
+% 1. All current macro packages run smoothly on top of pdf(e)TeX, so those
+%   primitives are left untouched.
+% 2. Other non-TeX82 primitives in LuaTeX may cause name clashes with existing
+%   macros in macro packages, especially when the use very "natural" names
+%   such as \outputbox, \mathstyle etc. Such a probability for name clashes is
+%   highly undesirable if LuaTeX is to replace pdfTeX as the default engine
+%   some day, and still undesirable even if it does not, anyway, since some
+%   level of compatibility never hurts.
+% 3. The LuaTeX team refused to apply a systematic prefixing policy, but
+%   kindly provided a tool allowing to apply it. So we chose to use it.
+% 4. The 'luatex' prefix was chosen since it is already used as a prefix for
+%   some primitives, such as \luatexversion: since way, those promitive don't
+%   end up with a double prefix (see tex.enableprimitive in the luatex manual
+%   for details).
+% 5. The \directlua primitive is provided both with its natural name (allowing
+%   to easily detect LuaTeX-besed formats) and a prefixed version
+%   \luatexdirectlua (for consistency with \luatexlatelua).
+% 6. Various remarks
+%   (a) The obvious drawback of such a prefixing policy is that the names used
+%     by LaTeX or generic macro writer won't match the names used in the
+%     manual.  We hope this is compensated by the gain in backwards
+%     compatibility.
+%   (b) All primitives dealing with Unicode math already begin with \U, and
+%     maybe will match the names of XeTeX primitives some day, so maybe
+%     prefixing was not necessary/desirable for them. However, we tried to
+%     make the prefixing rule as simple as possible, so that point (a) doesn't
+%     get too annoying.
+%   (c) The final name of some primitive may sound strange, namely those
+%     already containing the name of an engine, such as \luatexOmegaVersion.
+%     However, since LuaTeX is not a drop-in replacement for Omega/Aleph, we
+%     felt it wrong to provide \OmegaVersion.
+%   (d) Maybe some day we'll realise that it is better to provide all
+%     primitives without prefixing at all, after all. If this happens, it will
+%     be easy to add the unprefixed primitives in the format while keeping the
+%     prefixed names for compatibility. It wouldn't work the other way round
+%     (ie, realising that we should not provide the unprefixed primitives
+%     would cause huge compatibility problems for all LuaTeX-specific macro
+%     packages).
+
+
diff --git a/Master/texmf/tex/generic/config/luatexiniconfig.tex b/Master/texmf/tex/generic/config/luatexiniconfig.tex
index 396237e5c50..fd70863e21d 100644
--- a/Master/texmf/tex/generic/config/luatexiniconfig.tex
+++ b/Master/texmf/tex/generic/config/luatexiniconfig.tex
@@ -1,12 +1,18 @@
 % $Id$
-% Enable LuaTeX primitives for INI mode (needed since 0.39.0)
-% Élie Roux & Manuel Pégourié-Gonnard, 2009. Public domain.
+% Enable and prefix LuaTeX primitives for Plain-based formats
+% Assumes LuaTeX 0.39.x or greater.
+% Manuel Pégourié-Gonnard, 2009. Public domain.
 \begingroup
 \catcode`\{=1
 \catcode`\}=2
-\expandafter\ifx\csname luatexversion\endcsname\relax
-  \let\luatexversion\undefined
-  \directlua{tex.enableprimitives('', tex.extraprimitives())}
-\fi
+\directlua{
+  % all primitives are enabled without prefixing
+  tex.enableprimitives('', 
+    tex.extraprimitives())
+  % for compatibility with LaTeX-based formats, also provide a prefixed version
+  % of some primitives too (see lualatexiniconfig.tex)
+  tex.enableprimitives('luatex', 
+    tex.extraprimitives('core', 'omega', 'aleph', 'luatex'))
+  }
 \endgroup
 \endinput
diff --git a/Master/texmf/tex/generic/config/luatexprimitives.tex b/Master/texmf/tex/generic/config/luatexprimitives.tex
deleted file mode 100644
index 2a16579847a..00000000000
--- a/Master/texmf/tex/generic/config/luatexprimitives.tex
+++ /dev/null
@@ -1,19 +0,0 @@
-% $Id$
-% Enable and prefix LuaTeX primitives for LaTeX-based formats
-% % Maybe Plain based formats too, for the sake of generic macros?
-% Manuel Pégourié-Gonnard, 2009. Public domain.
-\begingroup
-\catcode`\{=1
-\catcode`\}=2
-\expandafter\ifx\csname luatexversion\endcsname\relax
-  \let\luatexversion\undefined
-  \directlua{
-    % etex and pdftex primitives are enabled without prefixing
-    tex.enableprimitives('', 
-      tex.extraprimitives('etex', 'pdftex'))
-    % other primitives are prefixed with luatex
-    tex.enableprimitives('luatex', 
-      tex.extraprimitives('omega', 'alpeh', 'luatex'))
-    }
-\fi
-\endgroup