l3 (21dec15)

git-svn-id: svn://tug.org/texlive/trunk@39162 c570f23f-e606-0410-a88d-b1316a301751

4 files changed, 402 insertions, 143 deletions

diff --git a/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.dtx b/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.dtx
index 79d549806b8..c59d2eeb876 100644
--- a/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.dtx
+++ b/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.dtx
@@ -37,8 +37,8 @@
 %<*driver|package>
 % The version of expl3 required is tested as early as possible, as
 % some really old versions do not define \ProvidesExplPackage.
-\RequirePackage{expl3}[2015/11/04]
-%<package>\@ifpackagelater{expl3}{2015/11/04}
+\RequirePackage{expl3}[2015/12/20]
+%<package>\@ifpackagelater{expl3}{2015/12/20}
 %<package>  {}
 %<package>  {%
 %<package>    \PackageError{l3keys2e}{Support package l3kernel too old}
@@ -52,8 +52,8 @@
 %<package>  }
 \def\ExplFileName{l3keys2e}
 \def\ExplFileDescription{LaTeX2e option processing using LaTeX3 keys}
-\def\ExplFileDate{2015/11/04}
-\def\ExplFileVersion{6224}
+\def\ExplFileDate{2015/12/20}
+\def\ExplFileVersion{6326}
 %</driver|package>
 %<*driver>
 \documentclass[full]{l3doc}
diff --git a/Master/texmf-dist/source/latex/l3packages/xfrac/xfrac.dtx b/Master/texmf-dist/source/latex/l3packages/xfrac/xfrac.dtx
index d6f77268574..94875c846f7 100644
--- a/Master/texmf-dist/source/latex/l3packages/xfrac/xfrac.dtx
+++ b/Master/texmf-dist/source/latex/l3packages/xfrac/xfrac.dtx
@@ -38,8 +38,8 @@
 %<*driver|package>
 % The version of expl3 required is tested as early as possible, as
 % some really old versions do not define \ProvidesExplPackage.
-\RequirePackage{expl3}[2015/11/04]
-%<package>\@ifpackagelater{expl3}{2015/11/04}
+\RequirePackage{expl3}[2015/12/20]
+%<package>\@ifpackagelater{expl3}{2015/12/20}
 %<package>  {}
 %<package>  {%
 %<package>    \PackageError{xfrac}{Support package l3kernel too old}
@@ -54,8 +54,8 @@
 \RequirePackage{amstext,graphicx,l3keys2e,textcomp,xparse,xtemplate}
 \def\ExplFileName{xfrac}
 \def\ExplFileDescription{L3 Experimental split-level fractions}
-\def\ExplFileDate{2015/11/04}
-\def\ExplFileVersion{6224}
+\def\ExplFileDate{2015/12/20}
+\def\ExplFileVersion{6326}
 %</driver|package>
 %<*driver>
 \documentclass[full]{l3doc}
diff --git a/Master/texmf-dist/source/latex/l3packages/xparse/xparse.dtx b/Master/texmf-dist/source/latex/l3packages/xparse/xparse.dtx
index acb89c006d8..392b93262f9 100644
--- a/Master/texmf-dist/source/latex/l3packages/xparse/xparse.dtx
+++ b/Master/texmf-dist/source/latex/l3packages/xparse/xparse.dtx
@@ -41,8 +41,8 @@
 %<*driver|package>
 % The version of expl3 required is tested as early as possible, as
 % some really old versions do not define \ProvidesExplPackage.
-\RequirePackage{expl3}[2015/11/04]
-%<package>\@ifpackagelater{expl3}{2015/11/04}
+\RequirePackage{expl3}[2015/12/20]
+%<package>\@ifpackagelater{expl3}{2015/12/20}
 %<package>  {}
 %<package>  {%
 %<package>    \PackageError{xparse}{Support package l3kernel too old}
@@ -56,8 +56,8 @@
 %<package>  }
 \def\ExplFileName{xparse}
 \def\ExplFileDescription{L3 Experimental document command parser}
-\def\ExplFileDate{2015/11/04}
-\def\ExplFileVersion{6224}
+\def\ExplFileDate{2015/12/20}
+\def\ExplFileVersion{6326}
 %</driver|package>
 %<*driver>
 \documentclass[full]{l3doc}
@@ -195,6 +195,12 @@
 %     |-NoValue-| if not present.
 %   \item[G] As for \texttt{g} but returns \meta{default} if no value
 %     is given: \texttt{G}\marg{default}.
+%   \item[k] An optional \emph{key} argument which requires a \emph{value}:
+%     the key should be a single \meta{token}. If the key is not present,
+%     returns |-NoValue-|. \emph{This is an experimental type}.
+%   \item[K] As for \texttt{K} but returns \meta{default} if no value
+%     is given: \texttt{K}\meta{token}\marg{default}.
+%     \emph{This is an experimental type}.
 % \end{itemize}
 %
 % Using these specifiers, it is possible to create complex input syntax
@@ -282,7 +288,11 @@
 % \verb*|\foo{arg1} [arg2]| will not. This is so that trailing optional
 % arguments are not picked up \enquote{by accident} in input.
 %
-% There is one major exception to the rules listed above: when \pkg{xparse} is used to define what \TeX\ defines as \enquote{control symbols} in which the function name is made up of a single character, such as \enquote{\cmd{\\}}, spaces are \emph{not} ignored directly after them even for mandatory arguments.
+% There is one major exception to the rules listed above: when
+% \pkg{xparse} is used to define what \TeX\ defines as \enquote{control
+% symbols} in which the function name is made up of a single character,
+% such as \enquote{\cmd{\\}}, spaces are \emph{not} ignored directly
+% after them even for mandatory arguments.
 %
 % \subsection{Required delimited arguments}
 %
@@ -638,16 +648,17 @@
 %     \item The \enquote{optional group} argument types \texttt{g} and
 %       \texttt{G} are not available.
 %     \item The \enquote{verbatim} argument type \texttt{v} is not available.
+%     \item Argument processors (using \texttt{>}) are not available.
 %     \item It is not possible to differentiate between, for example
 %       |\foo[| and |\foo{[}|: in both cases the \texttt{[} will be
-%       interpreted as the start of an optional argument. As a result
+%       interpreted as the start of an optional argument. As a
 %       result, checking for optional arguments is less robust than
 %       in the standard version.
 %   \end{itemize}
 %   \pkg{xparse} will issue an error if an argument specifier is given
-%   which does not conform to the first three requirements. The last
+%   which does not conform to the first six requirements. The last
 %   item is an issue when the function is used, and so is beyond the
-%  scope of \pkg{xparse} itself.
+%   scope of \pkg{xparse} itself.
 % \end{function}
 %
 % \subsection{Access to the argument specification}
@@ -1103,8 +1114,8 @@
 % \begin{macro}{\@@_count_mandatory:n}
 % \begin{macro}{\@@_count_mandatory:N}
 % \begin{macro}[aux]{\@@_count_mandatory:N}
-%   To count up mandatory arguments before the main parsing run, the same
-%   approach is used. First, check if the current token is a short-cut for
+%   Loop through the signature to count up mandatory arguments before the
+%   main parsing run. First, check if the current token is a short-cut for
 %   another argument type. If it is, expand it and loop again. If not, then
 %   look for a \enquote{counting} function to check the argument type. No error
 %   is raised here if one is not found as one will be raised by later code.
@@ -1124,9 +1135,8 @@
   }
 \cs_new_protected:Npn \@@_count_mandatory_aux:N #1
   {
-    \cs_if_free:cTF { @@_count_type_ \token_to_str:N #1 :w }
+    \cs_if_exist_use:cF { @@_count_type_ \token_to_str:N #1 :w }
       { \@@_count_type_m:w }
-      { \use:c { @@_count_type_ \token_to_str:N #1 :w } }
   }
 %    \end{macrocode}
 % \end{macro}
@@ -1141,7 +1151,11 @@
 %     \@@_count_type_D:w,
 %     \@@_count_type_g:w,
 %     \@@_count_type_G:w,
+%     \@@_count_type_k:w,
+%     \@@_count_type_K:w,
 %     \@@_count_type_m:w,
+%     \@@_count_type_r:w,
+%     \@@_count_type_R:w,
 %     \@@_count_type_t:w,
 %     \@@_count_type_u:w
 %   }
@@ -1158,14 +1172,22 @@
 %   the case, the entire set up is abandoned to avoid any strange internal
 %   errors. The opportunity is also taken to make sure that where a single
 %   token is required, one has actually been supplied.
+%
+%   The third is that processors and the marker~|+| for long arguments
+%   must be followed by arguments.  For this, just check that the next
+%   token is not \cs{q_recursion_tail}, and remember to leave it after
+%   the looping macro.
 %    \begin{macrocode}
-\cs_new_protected:cpn { @@_count_type_>:w } #1
+\cs_new_protected:cpn { @@_count_type_>:w } #1#2
+  {
+    \quark_if_recursion_tail_stop_do:nn {#2} { \@@_bad_arg_spec:wn }
+    \@@_count_mandatory:N #2
+  }
+\cs_new_protected:cpn { @@_count_type_+:w } #1
   {
     \quark_if_recursion_tail_stop_do:nn {#1} { \@@_bad_arg_spec:wn }
-    \@@_count_mandatory:N
+    \@@_count_mandatory:N #1
   }
-\cs_new_protected_nopar:cpn { @@_count_type_+:w }
-  { \@@_count_mandatory:N }
 \cs_new_protected:Npn \@@_count_type_d:w #1#2
   {
     \@@_single_token_check:n {#1}
@@ -1187,6 +1209,18 @@
     \quark_if_recursion_tail_stop_do:nn {#1} { \@@_bad_arg_spec:wn }
     \@@_count_mandatory:N
   }
+\cs_new_protected:Npn \@@_count_type_k:w #1
+  {
+    \@@_single_token_check:n {#1}
+    \quark_if_recursion_tail_stop_do:Nn #1 { \@@_bad_arg_spec:wn }
+    \@@_count_mandatory:N
+  }
+\cs_new_protected:Npn \@@_count_type_K:w #1#2
+  {
+    \@@_single_token_check:n {#1}
+    \quark_if_recursion_tail_stop_do:nn {#2} { \@@_bad_arg_spec:wn }
+    \@@_count_mandatory:N
+  }
 \cs_new_protected_nopar:Npn \@@_count_type_m:w
   {
     \int_incr:N \l_@@_mandatory_args_int
@@ -1230,7 +1264,7 @@
 %    \begin{macrocode}
 \cs_new_protected:Npn \@@_single_token_check:n #1
   {
-    \tl_if_single:nF {#1}
+    \exp_args:Nx \tl_if_single_token:nF { \tl_trim_spaces:n {#1} }
       { \@@_single_token_check_aux:nwn {#1} }
   }
 \cs_new_protected:Npn \@@_single_token_check_aux:nwn
@@ -1273,7 +1307,7 @@
     \@@_prepare_signature:N #1 \q_recursion_tail \q_recursion_stop
   }
 %    \end{macrocode}
-%  The main looping function does not take an argument,but carries out the
+%  The main looping function does not take an argument, but carries out the
 %  reset on the processor boolean. This is split off from the rest of the
 %  process so that when actually setting up processors the flag-reset can
 %  be bypassed.
@@ -1323,12 +1357,12 @@
 %
 % \subsection{Setting up a standard signature}
 %
-% All of the argument-adding functions work in essentially the same
-% way, except the one for \texttt{m} arguments. Any collected \texttt{m}
-% arguments are added to the signature, then the appropriate grabber
-% is added to the signature. Some of the adding functions also pick up
-% one or more arguments, and are also added to the signature. All of the
-% functions then call the loop function \cs{@@_prepare_signature:N}.
+% Each argument-adding function appends to the signature a grabber (and
+% for some types, the delimiters or default value), except the one for
+% \texttt{m} arguments.  These are collected and added to the signature
+% all at once by \cs{@@_flush_m_args:}, called for every other argument
+% type.  All of the functions then call the loop function
+% \cs{@@_prepare_signature:N}.
 %
 % \begin{macro}{\@@_add_type_+:w}
 %   Making the next argument long means setting the flag and knocking one back
@@ -1355,8 +1389,8 @@
 %    \begin{macrocode}
 \cs_new_protected:cpn { @@_add_type_>:w } #1
   {
-    \bool_set_true:N \l_@@_processor_bool
     \@@_flush_m_args:
+    \bool_set_true:N \l_@@_processor_bool
     \int_decr:N \l_@@_current_arg_int
     \tl_put_right:Nn \l_@@_signature_tl { \@@_process_arg:n {#1} }
     \@@_prepare_signature_bypass:N
@@ -1404,6 +1438,22 @@
 %    \end{macrocode}
 % \end{macro}
 %
+% \begin{macro}{\@@_add_type_k:w, \@@_add_type_K:w}
+%   Similar to |d|/|D| type but just one token to store.
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_add_type_k:w #1
+  { \exp_args:NNo \@@_add_type_K:w #1 \c_@@_no_value_tl }
+\cs_new_protected:Npn \@@_add_type_K:w #1#2
+  {
+    \@@_flush_m_args:
+    \@@_add_grabber_optional:N K
+    \tl_put_right:Nn \l_@@_signature_tl { #1 {#2} }
+    \@@_prepare_signature:N
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
 % \begin{macro}{\@@_add_type_l:w}
 %   Finding \texttt{l} arguments is very simple: there is nothing to do
 %   other than add the grabber.
@@ -1462,7 +1512,7 @@
   {
     \@@_flush_m_args:
     \@@_add_grabber_optional:N t
-    \tl_put_right:Nn \l_@@_signature_tl { #1 }
+    \tl_put_right:Nn \l_@@_signature_tl {#1}
     \@@_prepare_signature:N
   }
 %    \end{macrocode}
@@ -1498,7 +1548,8 @@
 %   As \texttt{m} arguments are simply counted, there is a need to add
 %   them to the token register in a block. As this function can only
 %   be called if something other than \texttt{m} turns up, the flag can
-%   be switched here. The total number of mandatory arguments added to
+%   be switched here. The total number of mandatory arguments which
+%   remain to be added to
 %   the signature is also decreased by the appropriate amount.
 %    \begin{macrocode}
 \cs_new_protected_nopar:Npn \@@_flush_m_args:
@@ -1506,9 +1557,8 @@
     \int_compare:nNnT \l_@@_m_args_int > \c_zero
       {
         \tl_put_right:Nx \l_@@_signature_tl
-           { \exp_not:c { @@_grab_m_ \int_use:N \l_@@_m_args_int :w } }
-        \int_set:Nn \l_@@_mandatory_args_int
-          { \l_@@_mandatory_args_int - \l_@@_m_args_int }
+          { \exp_not:c { @@_grab_m_ \int_use:N \l_@@_m_args_int :w } }
+        \int_sub:Nn \l_@@_mandatory_args_int { \l_@@_m_args_int }
       }
     \int_zero:N \l_@@_m_args_int
   }
@@ -1607,7 +1657,7 @@
   }
 \cs_new_protected:Npn \@@_add_expandable_type_D:w #1#2
   {
-    \token_if_eq_meaning:NNTF #1 #2
+    \tl_if_eq:nnTF {#1} {#2}
       {
         \@@_add_expandable_grabber_optional:n { D_alt }
         \@@_add_expandable_type_D_aux:Nn #1
@@ -1678,6 +1728,34 @@
 % \end{macro}
 % \end{macro}
 %
+% \begin{macro}{\@@_add_expandable_type_k:w}
+% \begin{macro}{\@@_add_expandable_type_K:w}
+%    \begin{macrocode}
+\cs_new_protected_nopar:Npn \@@_add_expandable_type_k:w #1
+  {
+    \exp_args:NNo
+      \@@_add_expandable_type_K:w #1 \c_@@_no_value_tl
+  }
+\cs_new_protected_nopar:Npn \@@_add_expandable_type_K:w #1#2
+  {
+    \@@_add_expandable_grabber_optional:n { K }
+    \bool_if:NTF \l_@@_all_long_bool
+      { \cs_set:cpx }
+      { \cs_set_nopar:cpx }
+      { \l_@@_expandable_aux_name_tl } ##1 #1 ##2
+      { ##1 {##2} }
+    \tl_put_right:Nx \l_@@_signature_tl
+      {
+        \exp_not:c { \l_@@_expandable_aux_name_tl }
+        \exp_not:n { #1 {#2} }
+      }
+    \bool_set_false:N \l_@@_long_bool
+    \@@_prepare_signature:N
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
 % \begin{macro}{\@@_add_expandable_type_l:w}
 %   Invalid in expandable contexts (as the next left brace may have been
 %   inserted by \pkg{xparse} due to a failed search for an optional argument).
@@ -1719,13 +1797,13 @@
   }
 \cs_new_protected:Npn \@@_add_expandable_type_R:w #1#2
   {
-    \token_if_eq_meaning:NNTF #1 #2
+    \tl_if_eq:nnTF {#1} {#2}
       {
-        \@@_add_expandable_grabber_optional:n { R_alt }
+        \@@_add_expandable_grabber_mandatory:n { R_alt }
         \@@_add_expandable_type_D_aux:Nn #1
       }
       {
-        \@@_add_expandable_grabber_optional:n { R }
+        \@@_add_expandable_grabber_mandatory:n { R }
         \@@_add_expandable_type_D_aux:NNn #1#2
       }
   }
@@ -1744,7 +1822,7 @@
       { \l_@@_expandable_aux_name_tl } ##1 #1 {##1}
     \tl_put_right:Nx \l_@@_signature_tl
       {
-        \exp_not:c  { \l_@@_expandable_aux_name_tl }
+        \exp_not:c { \l_@@_expandable_aux_name_tl }
         \exp_not:N #1
       }
     \bool_set_false:N \l_@@_long_bool
@@ -1767,7 +1845,7 @@
 % \end{macro}
 %
 % \begin{macro}{\@@_add_expandable_type_v:w}
-%  Another forbidden type.
+%   Another forbidden type.
 %    \begin{macrocode}
 \cs_new_protected_nopar:Npn \@@_add_expandable_type_v:w
   {
@@ -1808,7 +1886,7 @@
   }
 \cs_new_protected_nopar:Npn \@@_add_expandable_long_check:
   {
-    \bool_if:nT { \l_@@_all_long_bool && ! ( \l_@@_long_bool ) }
+    \bool_if:nT { \l_@@_all_long_bool && ! \l_@@_long_bool }
       { \__msg_kernel_error:nn { xparse } { inconsistent-long } }
   }
 %    \end{macrocode}
@@ -1819,7 +1897,7 @@
 %
 % All of the grabbers follow the same basic pattern. The initial
 % function sets up the appropriate information to define
-% \cs{parse_grab_arg:w} to grab the argument. This means determining
+% \cs{@@_grab_arg:w} to grab the argument. This means determining
 % whether to use \cs{cs_set:Npn} or \cs{cs_set_nopar:Npn}, and for
 % optional arguments whether to skip spaces. In all cases,
 % \cs{@@_grab_arg:w} is then called to actually do the grabbing.
@@ -1890,7 +1968,8 @@
 %   grabbed argument is entirely enclosed by braces. There are a couple of
 %   extra factors to allow for: the argument might be entirely empty, and
 %   spaces at the start and end of the input must be retained around a brace
-%   group.
+%   group. Also notice that a \emph{blank} argument might still contain
+%   spaces.
 %    \begin{macrocode}
 \cs_new_protected:Npn \@@_grab_D_aux:NNnN #1#2#3#4
   {
@@ -2059,6 +2138,56 @@
 % \end{macro}
 % \end{macro}
 %
+% \begin{macro}{\@@_grab_K:w, \@@_grab_K_long:w}
+% \begin{macro}[aux]{\@@_grab_K_aux:nnnNn}
+%   Look ahead at one token and if it matches grab an argument.
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_grab_K:w #1#2#3 \l_@@_args_tl
+  {
+    \@@_grab_K_aux:nnnNn
+      {#1} {#2} {#3}
+      \cs_set_protected_nopar:Npn
+      { _ignore_spaces }
+  }
+\cs_new_protected:Npn \@@_grab_K_long:w #1#2#3 \l_@@_args_tl
+  {
+    \@@_grab_K_aux:nnnNn
+      {#1} {#2} {#3}
+      \cs_set_protected:Npn
+      { _ignore_spaces }
+  }
+\cs_new_protected:Npn \@@_grab_K_trailing:w #1#2#3 \l_@@_args_tl
+  {
+    \@@_grab_K_aux:nnnNn
+      {#1} {#2} {#3}
+      \cs_set_protected_nopar:Npn
+      { }
+  }
+\cs_new_protected:Npn \@@_grab_K_long_trailing:w #1#2#3 \l_@@_args_tl
+  {
+    \@@_grab_K_aux:nnnNn
+      {#1} {#2} {#3}
+      \cs_set_protected:Npn
+      { }
+  }
+\cs_new_protected:Npn \@@_grab_K_aux:nnnNn #1#2#3#4#5
+ {
+   \exp_after:wN #4 \l_@@_fn_tl ##1
+     {
+       \@@_add_arg:n {##1}
+       #3 \l_@@_args_tl
+     }
+   \use:c { peek_meaning_remove #5 :NTF } #1
+     { \l_@@_fn_tl }
+     {
+       \@@_add_arg:n {#2}
+       #3 \l_@@_args_tl
+     }
+ }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
 % \begin{macro}{\@@_grab_l:w}
 % \begin{macro}{\@@_grab_l_long:w}
 % \begin{macro}[aux]{\@@_grab_l_aux:nN}
@@ -2413,7 +2542,7 @@
       { \@@_grab_v_aux_loop:NN #1 }
       { \@@_grab_v_aux_abort:n { } }
   }
-\cs_new_protected:Npn \@@_grab_v_aux_loop:NN #1 #2
+\cs_new_protected:Npn \@@_grab_v_aux_loop:NN #1#2
   {
     \@@_grab_v_token_if_char:NTF #2
       {
@@ -2675,7 +2804,7 @@
   {
     \str_if_eq:onTF
       { #1 { } { } #7 #2 \q_@@ #3 }
-      { { } { #2 } { } }
+      { { } {#2} { } }
       {
         #1
           { \@@_expandable_grab_D:NNNwNnnn #1#2#3#5 \q_@@ #6 }
@@ -2717,7 +2846,7 @@
       { #3 { \use_none:nnn } #2 \q_@@ #5 #4 \q_@@ #5 }
       {
         \tl_if_blank:oTF { \use_none:nn #1#2 }
-          { \@@_put_arg_expandable:ow { } }
+          { \@@_put_arg_expandable:ow { \use_none:nn #1#2 } }
           {
             \str_if_eq_x:nnTF
               { \exp_not:o { \use_none:nn #1#2 } }
@@ -2725,7 +2854,7 @@
               { \@@_put_arg_expandable:ow { \use_iii:nnn #1#2 } }
               { \@@_put_arg_expandable:ow { \use_none:nn #1#2 } }
           }
-          #6 \q_@@ #7
+            #6 \q_@@ #7
       }
       {
         #3
@@ -2763,8 +2892,8 @@
   }
 \cs_new:Npn \@@_expandable_grab_D_alt:Nwn #1#2 \q_@@ #3
   {
-    \tl_if_blank:oTF { \use_none:nn #1#2 }
-      { \@@_put_arg_expandable:ow { } }
+    \tl_if_blank:oTF { \use_none:n #3 }
+      { \@@_put_arg_expandable:ow { \use_none:n #3 } }
       {
         \str_if_eq_x:nnTF
           { \exp_not:o { \use_none:n #3 } }
@@ -2772,13 +2901,36 @@
           { \@@_put_arg_expandable:ow { \use_ii:nn #3 } }
           { \@@_put_arg_expandable:ow { \use_none:n #3 } }
       }
-      #2 \q_@@ #1
+        #2 \q_@@ #1
   }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
 % \end{macro}
 %
+% \begin{macro}[EXP]{\@@_expandable_grab_K:w}
+% \begin{macro}[EXP, aux]{\@@_expandable_grab_K_aux:NNwn}
+%   As for the |D|-type grabber, use the auxiliary to do the look ahead
+%   test then reuse it for the grabbing.
+%    \begin{macrocode}
+\cs_new:Npn \@@_expandable_grab_K:w #1 \q_@@ #2
+  { #2 { \@@_expandable_grab_K_aux:NNwn #1 \q_@@ #2 } }
+\cs_new:Npn \@@_expandable_grab_K_aux:NNwn #1#2#3#4 \q_@@ #5#6
+  {
+    \str_if_eq:onTF { #1 { } #6 { } #2 { } } { { } #2 { } }
+      {
+        #1
+          { \@@_expandable_grab_K_aux:Nwn #5 #4 \q_@@ }
+          #6
+      }
+      { #4 {#3} \q_@@ #5 {#6} }
+  }
+\cs_new:Npn \@@_expandable_grab_K_aux:Nwn #1#2 \q_@@ #3
+  { #2 {#3} \q_@@ #1 }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
 % \begin{macro}[EXP]{\@@_expandable_grab_m:w}
 % \begin{macro}[EXP, aux]{\@@_expandable_grab_m_aux:wNn}
 %   The mandatory case is easy: find the auxiliary after the \cs{q_@@}, and
@@ -2803,7 +2955,7 @@
   {
     \str_if_eq:onTF
       { #1 { } { } #7 #2 \q_@@ #3 }
-      { { } { #2 } { } }
+      { { } {#2} { } }
       {
         #1
           { \@@_expandable_grab_D:NNNwNnnn #1#2#3#5 \q_@@ #6 }
@@ -2857,7 +3009,7 @@
   { #2 { \@@_expandable_grab_t_aux:NNwn #1 \q_@@ #2 } }
 \cs_new:Npn \@@_expandable_grab_t_aux:NNwn #1#2#3 \q_@@ #4#5
   {
-    \str_if_eq:onTF { #1 { } #5 #2 } { #2 }
+    \str_if_eq:onTF { #1 { } #5 #2 } {#2}
       { #3 { \BooleanTrue } \q_@@ #4 }
       { #3 { \BooleanFalse } \q_@@ #4 {#5} }
   }
@@ -2890,20 +3042,13 @@
 \cs_new_protected:Npn \@@_process_arg:n #1
   {
     \int_incr:N \l_@@_processor_int
-    \cs_set:cpn { @@_processor_ \int_use:N \l_@@_processor_int :n } ##1
-      { #1 {##1} }
+    \cs_set_protected:cpx
+      { @@_processor_ \int_use:N \l_@@_processor_int :n } ##1
+      { \exp_not:n {#1} {##1} }
   }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}{\@@_process_to_str:n}
-%   A basic argument processor: as much an example as anything else.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_process_to_str:n #1
-  { \tl_set:Nx \ProcessedArgument { \tl_to_str:n {#1} } }
-%    \end{macrocode}
-% \end{macro}
-%
 % \begin{macro}{\@@_bool_reverse:N}
 %   A simple reversal.
 %    \begin{macrocode}
@@ -2928,15 +3073,15 @@
 \tl_new:N \l_@@_split_list_tl
 \cs_new_protected:Npn \@@_split_list:nn #1#2
   {
-    \bool_if:nTF
+    \tl_if_single:nTF {#1}
       {
-          \tl_if_single_p:n {#1} &&
-        ! ( \token_if_cs_p:N #1 )
+        \token_if_cs:NTF #1
+          { \@@_split_list_multi:nn {#1} {#2} }
+          { \@@_split_list_single:Nn #1 {#2} }
       }
-      { \@@_split_list_single:Nn #1 {#2} }
       { \@@_split_list_multi:nn {#1} {#2} }
-    }
-\cs_set_protected:Npn \@@_split_list_multi:nn #1#2
+  }
+\cs_new_protected:Npn \@@_split_list_multi:nn #1#2
   {
     \seq_set_split:Nnn \l_@@_split_list_seq {#1} {#2}
     \tl_clear:N \ProcessedArgument
@@ -2945,16 +3090,16 @@
   }
 \cs_generate_variant:Nn \@@_split_list_multi:nn { nV }
 \group_begin:
-\char_set_catcode_active:N \@
+\char_set_catcode_active:N \^^@
 \cs_new_protected:Npn \@@_split_list_single:Nn #1#2
   {
     \tl_set:Nn \l_@@_split_list_tl {#2}
     \group_begin:
-    \char_set_lccode:nn { `\@ } { `#1 }
+    \char_set_lccode:nn { `\^^@ } { `#1 }
     \tex_lowercase:D
       {
         \group_end:
-        \tl_replace_all:Nnn \l_@@_split_list_tl { @ }
+        \tl_replace_all:Nnn \l_@@_split_list_tl { ^^@ }
       }   {#1}
      \@@_split_list_multi:nV {#1} \l_@@_split_list_tl
    }
@@ -2968,7 +3113,7 @@
 % \begin{macro}{\@@_split_argument:nnn}
 % \begin{macro}[aux]{\@@_split_argument_aux:nnnn}
 % \begin{macro}[aux, EXP]{\@@_split_argument_aux:n}
-% \begin{macro}[aux, EXP]{\@@_split_argument_aux:wn}
+% \begin{macro}[aux, rEXP]{\@@_split_argument_aux:wn}
 %   Splitting to a known number of items is a special version of splitting
 %   a list, in which the limit is hard-coded and where there will always be
 %   exactly the correct number of output items. An auxiliary function is
@@ -3037,33 +3182,58 @@
 %
 % \subsection{Access to the argument specification}
 %
+% \begin{macro}{\@@_get_arg_spec_error:N, \@@_get_arg_spec_error:n}
+%   Provide an informative error when trying to get the argument
+%   specification of a non-\pkg{xparse} command or environment.
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_get_arg_spec_error:N #1
+  {
+    \cs_if_exist:NTF #1
+      {
+        \__msg_kernel_error:nnx { xparse } { non-xparse-command }
+          { \token_to_str:N #1 }
+      }
+      {
+        \__msg_kernel_error:nnx { xparse } { unknown-command }
+          { \token_to_str:N #1 }
+      }
+  }
+\cs_new_protected:Npn \@@_get_arg_spec_error:n #1
+  {
+    \cs_if_exist:cTF {#1}
+      {
+        \__msg_kernel_error:nnx { xparse } { non-xparse-environment }
+          { \tl_to_str:n {#1} }
+      }
+      {
+        \__msg_kernel_error:nnx { xparse } { unknown-environment }
+          { \tl_to_str:n {#1} }
+      }
+  }
+%    \end{macrocode}
+% \end{macro}
+%
 % \begin{macro}{\@@_get_arg_spec:N}
 % \begin{macro}{\@@_get_arg_spec:n}
-% \begin{macro}{\ArgumentSpecification}
-%   Recovering the argument specification is also trivial, using the
-%   \cs{tl_set_eq:cN} function.
+% \begin{variable}{\ArgumentSpecification}
+%   Recovering the argument specification is trivial, using the
+%   branching \cs{prop_get:NnN} function.
 %    \begin{macrocode}
 \cs_new_protected:Npn \@@_get_arg_spec:N #1
   {
     \prop_get:NnNF \l_@@_command_arg_specs_prop {#1}
       \ArgumentSpecification
-      {
-        \__msg_kernel_error:nnx { xparse } { unknown-document-command }
-          { \token_to_str:N #1 }
-      }
+      { \@@_get_arg_spec_error:N #1 }
   }
 \cs_new_protected:Npn \@@_get_arg_spec:n #1
   {
     \prop_get:NnNF \l_@@_environment_arg_specs_prop {#1}
       \ArgumentSpecification
-      {
-        \__msg_kernel_error:nnx { xparse } { unknown-document-environment }
-          { \tl_to_str:n {#1} }
-      }
+      { \@@_get_arg_spec_error:n {#1} }
   }
 \tl_new:N \ArgumentSpecification
 %    \end{macrocode}
-% \end{macro}
+% \end{variable}
 % \end{macro}
 % \end{macro}
 %
@@ -3077,20 +3247,14 @@
     \prop_get:NnNTF \l_@@_command_arg_specs_prop {#1}
       \ArgumentSpecification
       { \tl_show:N \ArgumentSpecification }
-      {
-        \__msg_kernel_error:nnx { xparse } { unknown-document-command }
-          { \token_to_str:N #1 }
-      }
+      { \@@_get_arg_spec_error:N #1 }
   }
 \cs_new_protected:Npn \@@_show_arg_spec:n #1
   {
     \prop_get:NnNTF \l_@@_environment_arg_specs_prop {#1}
       \ArgumentSpecification
       { \tl_show:N \ArgumentSpecification }
-      {
-        \__msg_kernel_error:nnx { xparse } { unknown-document-environment }
-          { \tl_to_str:n {#1} }
-      }
+      { \@@_get_arg_spec_error:n {#1} }
   }
 %    \end{macrocode}
 % \end{macro}
@@ -3100,8 +3264,8 @@
 %
 % \begin{macro}[TF]{\@@_if_no_value:n}
 %   Tests for |-NoValue-|: this is similar to \cs{tl_if_in:nn} but set
-%   up to be expandable.  The question mark prevents the auxiliary from
-%   losing braces.
+%   up to be expandable and to check the value exactly.  The question
+%   mark prevents the auxiliary from losing braces.
 %    \begin{macrocode}
 \use:x
   {
@@ -3118,15 +3282,65 @@
           { \exp_not:N \prg_return_false: }
       }
     \cs_new:Npn \exp_not:N \@@_if_value_aux:w ##1 \c_@@_no_value_tl
-      { ##1 }
-  }
+      {##1}
+  }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_check_definable:nNT, \@@_check_definable_aux:nN}
+%   Check that a token list is appropriate as a first argument of
+%   \cs{DeclareDocumentCommand} and similar functions and otherwise
+%   produce an error.  First trim whitespace to allow for spaces around
+%   the actual command to be defined.  If the result has multiple
+%   tokens, it is not a valid argument.  The single token is a control
+%   sequence exactly if its string representation has more than one
+%   character (using \cs{token_to_str:N} rather than \cs{tl_to_str:n}
+%   to avoid problems with macro parameter characters, and setting
+%   \cs{tex_escapechar:D} to prevent it from being non-printable).
+%   Finally, check for an active character: this is done by lowercasing
+%   the token to fix its character code (arbitrarily to that of~|?|)
+%   and comparing the result to an active~|?|.  Both control sequences
+%   and active characters are valid arguments, and non-active character
+%   tokens are not.  In all cases, the group opened to keep assignments
+%   local must be closed.
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_check_definable:nNT #1
+  { \exp_args:Nx \@@_check_definable_aux:nN { \tl_trim_spaces:n {#1} } }
+\group_begin:
+  \char_set_catcode_active:n { `? }
+  \cs_new_protected:Npn \@@_check_definable_aux:nN #1#2
+    {
+      \group_begin:
+      \tl_if_single_token:nTF {#1}
+        {
+          \int_set:Nn \tex_escapechar:D { 92 }
+          \exp_args:Nx \tl_if_empty:nTF
+            { \exp_args:No \str_tail:n { \token_to_str:N #1 } }
+            {
+              \exp_args:Nx \char_set_lccode:nn
+                { ` \str_head:n {#1} } { `? }
+              \tex_lowercase:D { \tl_if_eq:nnTF {#1} } { ? }
+                { \group_end: \use_iii:nnn }
+                { \group_end: \use_i:nnn }
+            }
+            { \group_end: \use_iii:nnn }
+        }
+        { \group_end: \use_ii:nnn }
+      {
+        \__msg_kernel_error:nnxx { xparse } { not-definable }
+          { \tl_to_str:n {#1} } { \token_to_str:N #2 }
+      }
+      {
+        \__msg_kernel_error:nnxx { xparse } { not-one-token }
+          { \tl_to_str:n {#1} } { \token_to_str:N #2 }
+      }
+    }
+\group_end:
 %    \end{macrocode}
 % \end{macro}
 %
 % \subsection{Messages}
 %
-% \subsection{Messages}
-%
 % Some messages intended as errors.
 %    \begin{macrocode}
 \__msg_kernel_new:nnnn { xparse } { bad-arg-spec }
@@ -3158,12 +3372,6 @@
     with~an~environment~that~already~has~a~definition. \\
     The~existing~definition~of~'#1'~will~be~overwritten.
   }
-\__msg_kernel_new:nnnn { xparse } { environment-mismatch }
-  { Mismatch~between~start~and~end~of~environment. }
-  {
-    The~current~environment~is~called~'#1',~but~you~have~tried~to~
-    end~one~called~'#2'.~Environments~have~to~be~properly~nested.
-  }
 \__msg_kernel_new:nnnn { xparse } { environment-not-yet-defined }
   { Environment~'#1'~not~yet~defined! }
   {
@@ -3171,13 +3379,6 @@
     with~an~environment~that~was~never~defined. \\
     A~new~environment~'#1'~will~be~created.
   }
-\__msg_kernel_new:nnnn { xparse } { environment-unknown }
-  { Environment~'#1'~undefined. }
-  {
-    You~have~tried~to~start~an~environment~called~'#1',~
-    but~this~has~never~been~defined. \\
-    The~command~will~be~ignored.
-  }
 \__msg_kernel_new:nnnn { xparse } { expandable-ending-optional }
   {
     Argument~specification~for~expandable~command~ends~with~optional~argument.
@@ -3211,6 +3412,38 @@
     '#1'.~LaTeX~did~not~find~it,~and~will~insert~'#2'~as~the~value~to~be~
     processed.
   }
+\__msg_kernel_new:nnnn { xparse } { non-xparse-command }
+  { Command~'#1'~not~defined~using~xparse. }
+  {
+    You~have~asked~for~the~argument~specification~for~a~command~'#1',~
+    but~this~is~not~a~command~defined~using~xparse.
+  }
+\__msg_kernel_new:nnnn { xparse } { non-xparse-environment }
+  { Environment~'#1'~not~defined~using~xparse. }
+  {
+    You~have~asked~for~the~argument~specification~for~an~environment~'#1',~
+    but~this~is~not~an~environment~defined~using~xparse.
+  }
+\__msg_kernel_new:nnnn { xparse } { not-definable }
+  { First~argument~of~'#2'~must~be~a~command. }
+  {
+    \c__msg_coding_error_text_tl
+    The~first~argument~of~'#2'~should~be~the~document~command~that~will~
+    be~defined.~The~provided~argument~'#1'~is~a~character.~Perhaps~a~
+    backslash~is~missing?
+    \\ \\
+    LaTeX~will~ignore~this~entire~definition.
+  }
+\__msg_kernel_new:nnnn { xparse } { not-one-token }
+  { First~argument~of~'#2'~must~be~a~command. }
+  {
+    \c__msg_coding_error_text_tl
+    The~first~argument~of~'#2'~should~be~the~document~command~that~will~
+    be~defined.~The~provided~argument~'#1'~contains~more~than~one~
+    token.
+    \\ \\
+    LaTeX~will~ignore~this~entire~definition.
+  }
 \__msg_kernel_new:nnnn { xparse } { not-single-token }
   { Argument~delimiter~should~be~a~single~token:~'#1'. }
   {
@@ -3240,17 +3473,17 @@
     The~letter~'#1'~does~not~specify~a~known~argument~type.~
     LaTeX~will~assume~you~want~a~standard~mandatory~argument~(type~'m').
   }
-\__msg_kernel_new:nnnn { xparse } { unknown-document-command }
+\__msg_kernel_new:nnnn { xparse } { unknown-command }
   { Unknown~document~command~'#1'. }
   {
     You~have~asked~for~the~argument~specification~for~a~command~'#1',~
-    but~this~is~not~a~document~command.
+    but~it~is~not~defined.
   }
-\__msg_kernel_new:nnnn { xparse } { unknown-document-environment }
+\__msg_kernel_new:nnnn { xparse } { unknown-environment }
   { Unknown~document~environment~'#1'. }
   {
-    You~have~asked~for~the~argument~specification~for~a~command~'#1',~
-    but~this~is~not~a~document~environment.
+    You~have~asked~for~the~argument~specification~for~an~environment~'#1',~
+    but~it~is~not~defined.
   }
 \__msg_kernel_new:nnnn { xparse } { verbatim-newline }
   { Verbatim~argument~of~'#1'~ended~by~end~of~line. }
@@ -3319,29 +3552,43 @@
 % \begin{macro}{\RenewDocumentCommand}
 % \begin{macro}{\ProvideDocumentCommand}
 %   The user macros are pretty simple wrappers around the internal ones.
+%   There is however a check that the first argument is a single token
+%   and is definable.
 %    \begin{macrocode}
 \cs_new_protected:Npn \DeclareDocumentCommand #1#2#3
-  { \@@_declare_cmd:Nnn #1 {#2} {#3} }
+  {
+    \@@_check_definable:nNT {#1} \DeclareDocumentCommand
+      { \@@_declare_cmd:Nnn #1 {#2} {#3} }
+  }
 \cs_new_protected:Npn \NewDocumentCommand #1#2#3
   {
-    \cs_if_exist:NTF #1
+    \@@_check_definable:nNT {#1} \NewDocumentCommand
       {
-        \__msg_kernel_error:nnx { xparse } { command-already-defined }
-          { \token_to_str:N #1 }
+        \cs_if_exist:NTF #1
+          {
+            \__msg_kernel_error:nnx { xparse } { command-already-defined }
+              { \token_to_str:N #1 }
+          }
+          { \@@_declare_cmd:Nnn #1 {#2} {#3} }
       }
-      { \@@_declare_cmd:Nnn #1 {#2} {#3} }
   }
 \cs_new_protected:Npn \RenewDocumentCommand #1#2#3
   {
-    \cs_if_exist:NTF #1
-      { \@@_declare_cmd:Nnn #1 {#2} {#3} }
+    \@@_check_definable:nNT {#1} \RenewDocumentCommand
       {
-        \__msg_kernel_error:nnx { xparse } { command-not-yet-defined }
-          { \token_to_str:N #1 }
+        \cs_if_exist:NTF #1
+          { \@@_declare_cmd:Nnn #1 {#2} {#3} }
+          {
+            \__msg_kernel_error:nnx { xparse } { command-not-yet-defined }
+              { \token_to_str:N #1 }
+          }
       }
   }
 \cs_new_protected:Npn \ProvideDocumentCommand #1#2#3
-  { \cs_if_exist:NF #1 { \@@_declare_cmd:Nnn #1 {#2} {#3} } }
+  {
+    \@@_check_definable:nNT {#1} \ProvideDocumentCommand
+      { \cs_if_exist:NF #1 { \@@_declare_cmd:Nnn #1 {#2} {#3} } }
+ }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -3369,7 +3616,7 @@
       { \__msg_kernel_error:nnx { xparse } { environment-not-yet-defined } {#1} }
   }
 \cs_new_protected:Npn \ProvideDocumentEnvironment #1#2#3#4
-  { \cs_if_exist:cF { #1 } { \@@_declare_env:nnnn {#1} {#2} {#3} {#4} } }
+  { \cs_if_exist:cF {#1} { \@@_declare_env:nnnn {#1} {#2} {#3} {#4} } }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -3380,7 +3627,10 @@
 %   The expandable version of the basic function is essentially the same.
 %    \begin{macrocode}
 \cs_new_protected:Npn \DeclareExpandableDocumentCommand #1#2#3
-  { \@@_declare_expandable_cmd:Nnn #1 {#2} {#3} }
+  {
+    \@@_check_definable:nNT {#1} \DeclareExpandableDocumentCommand
+      { \@@_declare_expandable_cmd:Nnn #1 {#2} {#3} }
+  }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -3406,9 +3656,9 @@
 % \begin{macro}[TF]{\IfValue}
 %   Inverted logic.
 %    \begin{macrocode}
-\cs_set:Npn \IfValueF { \@@_if_no_value:nT }
-\cs_set:Npn \IfValueT { \@@_if_no_value:nF }
-\cs_set:Npn \IfValueTF #1#2#3 { \@@_if_no_value:nTF {#1} {#3} {#2} }
+\cs_new_nopar:Npn \IfValueF { \@@_if_no_value:nT }
+\cs_new_nopar:Npn \IfValueT { \@@_if_no_value:nF }
+\cs_new:Npn \IfValueTF #1#2#3 { \@@_if_no_value:nTF {#1} {#3} {#2} }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -3441,11 +3691,20 @@
 % \begin{macro}{\GetDocumentEnvironmentArgSpec}
 % \begin{macro}{\ShowDocumentCommandArgSpec}
 % \begin{macro}{\ShowDocumentEnvironmentArgSpec}
-%   More simple mappings.
+%   More simple mappings, with a check that the argument is a single
+%   control sequence or active character.
 %    \begin{macrocode}
-\cs_new_eq:NN \GetDocumentCommandArgSpec      \@@_get_arg_spec:N
-\cs_new_eq:NN \GetDocumentEnvironmmentArgSpec \@@_get_arg_spec:n
-\cs_new_eq:NN \ShowDocumentCommandArgSpec     \@@_show_arg_spec:N
+\cs_new_protected:Npn \GetDocumentCommandArgSpec #1
+  {
+    \@@_check_definable:nNT {#1} \GetDocumentCommandArgSpec
+      { \@@_get_arg_spec:N #1 }
+  }
+\cs_new_eq:NN \GetDocumentEnvironmentArgSpec \@@_get_arg_spec:n
+\cs_new_protected:Npn \ShowDocumentCommandArgSpec #1
+  {
+    \@@_check_definable:nNT {#1} \ShowDocumentCommandArgSpec
+      { \@@_show_arg_spec:N #1 }
+  }
 \cs_new_eq:NN \ShowDocumentEnvironmentArgSpec \@@_show_arg_spec:n
 %    \end{macrocode}
 % \end{macro}
diff --git a/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.dtx b/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.dtx
index d08e257b053..b2e0edc7cc6 100644
--- a/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.dtx
+++ b/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.dtx
@@ -41,8 +41,8 @@
 %<*driver|package>
 % The version of expl3 required is tested as early as possible, as
 % some really old versions do not define \ProvidesExplPackage.
-\RequirePackage{expl3}[2015/11/04]
-%<package>\@ifpackagelater{expl3}{2015/11/04}
+\RequirePackage{expl3}[2015/12/20]
+%<package>\@ifpackagelater{expl3}{2015/12/20}
 %<package>  {}
 %<package>  {%
 %<package>    \PackageError{xtemplate}{Support package l3kernel too old}
@@ -56,8 +56,8 @@
 %<package>  }
 \def\ExplFileName{xtemplate}
 \def\ExplFileDescription{L3 Experimental prototype document functions}
-\def\ExplFileDate{2015/11/04}
-\def\ExplFileVersion{6224}
+\def\ExplFileDate{2015/12/20}
+\def\ExplFileVersion{6326}
 %</driver|package>
 %<*driver>
 \documentclass[full]{l3doc}