l3kernel 2564 (13aug11)

git-svn-id: svn://tug.org/texlive/trunk@23540 c570f23f-e606-0410-a88d-b1316a301751

12 files changed, 342 insertions, 169 deletions

diff --git a/Master/texmf-dist/tex/latex/l3kernel/expl3.sty b/Master/texmf-dist/tex/latex/l3kernel/expl3.sty
index 73956b2e93d..b802a008132 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/expl3.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/expl3.sty
@@ -48,9 +48,8 @@
 \RequirePackage{l3names}
 \def\ExplFileName{expl3}
 \def\ExplFileDescription{L3 Experimental code bundle wrapper}
-\def\ExplFileDate{2011/08/10}
-\def\ExplFileVersion{2535}
- %\subsubsection{Variables: scope and type}
+\def\ExplFileDate{2011/08/13}
+\def\ExplFileVersion{2564}
 \RequirePackage{etex}
 \reserveinserts{32}
 \RequirePackage{calc}
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3bootstrap.sty b/Master/texmf-dist/tex/latex/l3kernel/l3bootstrap.sty
index 9b0e0c03fe4..4c575fdc144 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3bootstrap.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3bootstrap.sty
@@ -94,7 +94,7 @@
   {\def\ExplFileDate{#2}}
 \protected\def\GetIdInfoAuxSVN#1\relax#2-#3-#4\relax#5Z\relax
   {\def\ExplFileDate{#2/#3/#4}}
-\GetIdInfo$Id: l3bootstrap.dtx 2519 2011-08-08 09:35:54Z mittelba $
+\GetIdInfo$Id: l3bootstrap.dtx 2558 2011-08-13 06:32:00Z joseph $
   {L3 experimental bootstrap code}
 \ProvidesPackage{l3bootstrap}
   [%
@@ -290,9 +290,9 @@
 \protected\edef\ExplSyntaxNamesOff
   {%
     \expandafter\noexpand
-      \csname\detokenize{char_set_catcode_math_subscript:n}\endcsname{58}%
+      \csname\detokenize{char_set_catcode_other:n}\endcsname{58}%
     \expandafter\noexpand
-      \csname\detokenize{char_set_catcode_other:n}\endcsname{95}%
+      \csname\detokenize{char_set_catcode_math_subscript:n}\endcsname{95}%
   }
 %% 
 %%
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3doc.cls b/Master/texmf-dist/tex/latex/l3kernel/l3doc.cls
index 258a8475eb9..00ef5ad8e58 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3doc.cls
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3doc.cls
@@ -52,7 +52,7 @@
 \let        \filedateOld        \ExplFileDate
 \let     \fileversionOld        \ExplFileVersion
 \let \filedescriptionOld        \ExplFileDescription
-\GetIdInfo$Id: l3doc.dtx 2478 2011-06-19 21:34:23Z joseph $
+\GetIdInfo$Id: l3doc.dtx 2540 2011-08-10 23:39:33Z bruno $
           {L3 Experimental documentation class}
 \ProvidesExplClass
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3expan.sty b/Master/texmf-dist/tex/latex/l3kernel/l3expan.sty
index 028e9cd3bc0..a818956cd5b 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3expan.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3expan.sty
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3names}
-\GetIdInfo$Id: l3expan.dtx 2480 2011-06-20 17:25:23Z bruno $
+\GetIdInfo$Id: l3expan.dtx 2545 2011-08-11 13:47:19Z bruno $
   {L3 Experimental argument expansion}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -98,12 +98,13 @@
   }
 \cs_new_nopar:Npn \exp_eval_register:c #1
   { \exp_after:wN \exp_eval_register:N \cs:w #1 \cs_end: }
-\group_begin:%
-\tex_catcode:D`\!=11\scan_stop:%
-\tex_catcode:D`\ =11\scan_stop:%
-\cs_new:Npn\exp_eval_error_msg:w#1\tex_the:D#2{%
-\fi:\fi:\exp_after:wN\c_zero\erroneous variable used!}%
-\group_end:%
+\cs_new:Npn \exp_eval_error_msg:w #1 \tex_the:D #2
+  {
+      \fi:
+    \fi:
+    \msg_expandable_error:n { Erroneous ~ variable ~ #2 used! }
+    \c_zero
+  }
 \cs_new:Npn \exp_args:No #1#2 { \exp_after:wN #1 \exp_after:wN {#2} }
 \cs_new:Npn \exp_args:NNo #1#2#3
   { \exp_after:wN #1 \exp_after:wN #2 \exp_after:wN {#3} }
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3int.sty b/Master/texmf-dist/tex/latex/l3kernel/l3int.sty
index be7df6fe8c9..809ed14ab66 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3int.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3int.sty
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3names}
-\GetIdInfo$Id: l3int.dtx 2526 2011-08-09 08:58:42Z joseph $
+\GetIdInfo$Id: l3int.dtx 2551 2011-08-11 22:40:53Z bruno $
   {L3 Experimental integers}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -531,7 +531,7 @@
   }
 \cs_new:Npn \int_get_sign_and_digits_aux:nNNN #1#2#3#4
   {
-    \tl_if_head_eq_charcode:fNTF {#1} -
+    \exp_args:Nf \tl_if_head_eq_charcode:nNTF {#1} -
       {
         \bool_if:NTF #2
           {
@@ -544,7 +544,7 @@
           }
       }
       {
-        \tl_if_head_eq_charcode:fNTF {#1} +
+        \exp_args:Nf \tl_if_head_eq_charcode:nNTF {#1} +
           { \int_get_sign_and_digits_aux:oNNN { \use_none:n #1 } #2#3#4 }
           {
             \bool_if:NT #3 { \bool_if:NF #2 - }
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3luatex.sty b/Master/texmf-dist/tex/latex/l3kernel/l3luatex.sty
index b7e63c89882..38e13e2b87b 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3luatex.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3luatex.sty
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3names}
-\GetIdInfo$Id: l3luatex.dtx 2478 2011-06-19 21:34:23Z joseph $
+\GetIdInfo$Id: l3luatex.dtx 2545 2011-08-11 13:47:19Z bruno $
   {L3 Experimental LuaTeX-specific functions}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -57,8 +57,16 @@
     \cs_new_eq:NN \lua_shipout_x:n \luatex_latelua:D
   }
   {
-    \cs_new:Npn \lua_now:x #1 { \lua_wrong_engine: }
-    \cs_new_protected:Npn \lua_shipout_x:n #1 { \lua_wrong_engine: }
+    \cs_new:Npn \lua_now:x #1
+      {
+        \msg_expandable_error:n
+          { LuaTeX~ engine~ not~ in~ use!~ Ignoring~ \lua_now:x. }
+      }
+    \cs_new_protected:Npn \lua_shipout_x:n #1
+      {
+        \msg_expandable_error:n
+          { LuaTeX~ engine~ not~ in~ use!~ Ignoring~ \lua_shipout_x:n. }
+      }
   }
 \cs_new:Npn \lua_now:n #1
   { \lua_now:x { \exp_not:n {#1} } }
@@ -66,13 +74,6 @@
 \cs_new_protected:Npn \lua_shipout:n #1
   { \lua_shipout_x:n { \exp_not:n {#1} } }
 \cs_generate_variant:Nn \lua_shipout:n { x }
-\group_begin:
-\char_set_catcode_letter:N\!
-\char_set_catcode_letter:N\ %
-\cs_gset:Npn\lua_wrong_engine:{%
-\LuaTeX engine not in use!%
-}%
-\group_end:%
 \int_new:N  \g_cctab_allocate_int
 \int_set:Nn \g_cctab_allocate_int { -1 }
 \int_new:N \g_cctab_stack_int
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3msg.sty b/Master/texmf-dist/tex/latex/l3kernel/l3msg.sty
index bf1d732514f..43ccc081d3d 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3msg.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3msg.sty
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3names}
-\GetIdInfo$Id: l3msg.dtx 2478 2011-06-19 21:34:23Z joseph $
+\GetIdInfo$Id: l3msg.dtx 2551 2011-08-11 22:40:53Z bruno $
   {L3 Experimental messages}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -539,6 +539,13 @@
     LaTeX~has~been~asked~to~recover~an~entry~from~a~sequence~that~
     has~no~content:~that~cannot~happen!
   }
+\msg_kernel_new:nnnn { tl } { empty-search-pattern }
+  { Empty~search~pattern. }
+  {
+    \c_msg_coding_error_text_tl
+    LaTeX~has~been~asked~to~replace~an~empty~pattern~by~'#1':~that~%
+    would~lead~to~an~infinite~loop!
+  }
 \cs_set_protected:Npn \msg_kernel_bug:x #1
   {
     \msg_interrupt:xxx { \c_msg_kernel_bug_text_tl }
@@ -556,6 +563,18 @@
     This~probably~needs~examining~by~an~expert.
     \c_msg_return_text_tl
   }
+\group_begin:
+\cs_new:Npx \msg_expandable_error:n #1
+  {
+    \exp_not:n
+      {
+        \exp_after:wN \exp_after:wN
+        \exp_after:wN \use_none_delimit_by_q_stop:w
+      }
+    \exp_not:N \use:n { \exp_not:c { LaTeX3 ~ error : } #1 }
+    \exp_not:N \q_stop
+  }
+\group_end:
 \cs_new_eq:NN \msg_class_new:nn \msg_class_set:nn
 \cs_new_eq:NN \msg_trace:nnxxxx \msg_log:nnxxxx
 \cs_new_eq:NN \msg_trace:nnxxx  \msg_log:nnxxx
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3names.sty b/Master/texmf-dist/tex/latex/l3kernel/l3names.sty
index a504049d1ed..498af47ed47 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3names.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3names.sty
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3names.dtx 2478 2011-06-19 21:34:23Z joseph $
+\GetIdInfo$Id: l3names.dtx 2538 2011-08-10 19:37:10Z joseph $
   {L3 Experimental namespace for primitives}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3prg.sty b/Master/texmf-dist/tex/latex/l3kernel/l3prg.sty
index 349cb85655d..29ace90b700 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3prg.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3prg.sty
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3names}
-\GetIdInfo$Id: l3prg.dtx 2509 2011-08-07 11:21:26Z bruno $
+\GetIdInfo$Id: l3prg.dtx 2553 2011-08-11 23:55:20Z bruno $
   {L3 Experimental control structures}
 %%
 \ProvidesExplPackage
@@ -307,7 +307,7 @@
   {
     \str_if_eq:xxTF {#1} {#2}
       { \prg_case_end:nw {#3} }
-      { \prg_case_str_aux:nw {#1} }
+      { \prg_case_str_x_aux:nw {#1} }
   }
 \cs_new:Npn \prg_case_tl:Nnn #1#2#3
   { \prg_case_tl_aux:Nw #1 #2 #1 {#3} \q_recursion_stop }
@@ -435,7 +435,7 @@
     \if_mode_math: \prg_return_true: \else: \prg_return_false: \fi:
   }
 \cs_new_nopar:Npn \group_align_safe_begin:
-  { \if_false: { \fi: \if_int_compare:w `} = \c_zero \fi: }
+  { \if_int_compare:w \if_false: { \fi: `} = \c_zero \fi: }
 \cs_new_nopar:Npn \group_align_safe_end:
   { \if_int_compare:w `{ = \c_zero } \fi: }
 \cs_new_nopar:Npn \scan_align_safe_stop:
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3quark.sty b/Master/texmf-dist/tex/latex/l3kernel/l3quark.sty
index 35a8ca8f8e7..236b34b5a0a 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3quark.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3quark.sty
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3names}
-\GetIdInfo$Id: l3quark.dtx 2478 2011-06-19 21:34:23Z joseph $
+\GetIdInfo$Id: l3quark.dtx 2549 2011-08-11 21:06:39Z bruno $
   {L3 Experimental quarks}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -149,6 +149,8 @@
 \cs_generate_variant:Nn \quark_if_nil:nTF { V , o }
 \cs_generate_variant:Nn \quark_if_nil:nT  { V , o }
 \cs_generate_variant:Nn \quark_if_nil:nF  { V , o }
+\quark_new:N \q_tl_act_mark
+\quark_new:N \q_tl_act_stop
 %% 
 %%
 %% End of file `l3quark.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3seq.sty b/Master/texmf-dist/tex/latex/l3kernel/l3seq.sty
index 13136da4828..ab1ec03f467 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3seq.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3seq.sty
@@ -46,14 +46,14 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3names}
-\GetIdInfo$Id: l3seq.dtx 2478 2011-06-19 21:34:23Z joseph $
+\GetIdInfo$Id: l3seq.dtx 2556 2011-08-12 14:00:43Z bruno $
   {L3 Experimental sequences and stacks}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
 \package_check_loaded_expl:
 \cs_new:Npn \seq_item:n
   {
-    \seq_use_error:
+    \msg_expandable_error:n { A~sequence~was~used~incorrectly. }
     \use_none:n
   }
 \tl_new:N \l_seq_tmpa_tl
@@ -522,6 +522,25 @@
 \cs_generate_variant:Nn \seq_gset_from_clist:NN {     Nc }
 \cs_generate_variant:Nn \seq_gset_from_clist:NN { c , cc }
 \cs_generate_variant:Nn \seq_gset_from_clist:Nn { c      }
+\cs_new_protected_nopar:Npn \seq_tmp:w
+  { \msg_expandable_error:n { There~is~a~bug~in~LaTeX3! } }
+\cs_new_protected_nopar:Npn \seq_set_reverse:N
+  { \seq_reverse_aux:NN \tl_set:Nx }
+\cs_new_protected_nopar:Npn \seq_gset_reverse:N
+  { \seq_reverse_aux:NN \tl_gset:Nx }
+\cs_new_protected_nopar:Npn \seq_reverse_aux:NN #1 #2
+  {
+    \cs_set_eq:NN \seq_tmp:w \seq_item:n
+    \cs_set_eq:NN \seq_item:n \seq_reverse_aux_item:w
+    #1 #2 { #2 \prg_do_nothing: }
+    \cs_set_eq:NN \seq_item:n \seq_tmp:w
+  }
+\cs_new:Npn \seq_reverse_aux_item:w #1 #2 \prg_do_nothing:
+  {
+    #2
+    \prg_do_nothing:
+    \exp_not:n { \seq_item:n {#1} }
+  }
 \cs_new_eq:NN \seq_top:NN \seq_get_left:NN
 \cs_new_eq:NN \seq_top:cN \seq_get_left:cN
 \cs_new_eq:NN \seq_display:N \seq_show:N
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3tl.sty b/Master/texmf-dist/tex/latex/l3kernel/l3tl.sty
index e86c27e6c34..b37aa775085 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3tl.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3tl.sty
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3names}
-\GetIdInfo$Id: l3tl.dtx 2534 2011-08-10 18:21:44Z joseph $
+\GetIdInfo$Id: l3tl.dtx 2563 2011-08-13 12:23:59Z joseph $
   {L3 Experimental token lists}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -175,6 +175,7 @@
     \group_begin:
       \exp_args:No \etex_everyeof:D { \c_tl_rescan_marker_tl }
       \tex_endlinechar:D \c_minus_one
+      \tex_newlinechar:D \c_minus_one
       #3
       \tl_clear:N \l_tl_rescan_tl
       \exp_after:wN \tl_rescan_aux:w \etex_scantokens:D {#4}
@@ -201,6 +202,7 @@
     \group_begin:
       \etex_everyeof:D { \exp_not:N }
       \tex_endlinechar:D \c_minus_one
+      \tex_newlinechar:D \c_minus_one
       #3
       \tl_set:Nx \l_tl_rescan_tl { \etex_scantokens:D {#4} }
     \exp_args:NNNo \group_end:
@@ -213,6 +215,7 @@
     \group_begin:
       \exp_args:No \etex_everyeof:D { \c_tl_rescan_marker_tl }
       \tex_endlinechar:D \c_minus_one
+      \tex_newlinechar:D \c_minus_one
       #1
       \exp_after:wN \tl_rescan_aux:w \etex_scantokens:D {#2}
     \exp_args:No \group_end:
@@ -222,60 +225,53 @@
 \cs_new_eq:NN \tl_to_uppercase:n \tex_uppercase:D
 \tl_new:N \l_tl_replace_tl
 \cs_new_protected_nopar:Npn \tl_replace_once:Nnn
-  { \tl_replace_once_aux:NNnn \tl_set_eq:NN }
+  { \tl_replace_aux:NNNnn \tl_replace_once_aux: \tl_set:Nx }
 \cs_new_protected_nopar:Npn \tl_greplace_once:Nnn
-  { \tl_replace_once_aux:NNnn \tl_gset_eq:NN }
-\cs_new_protected:Npn \tl_replace_once_aux:NNnn #1#2#3#4
+  { \tl_replace_aux:NNNnn \tl_replace_once_aux: \tl_gset:Nx }
+\cs_new_protected_nopar:Npn \tl_replace_all:Nnn
+  { \tl_replace_aux:NNNnn \tl_replace_all_aux: \tl_set:Nx }
+\cs_new_protected_nopar:Npn \tl_greplace_all:Nnn
+  { \tl_replace_aux:NNNnn \tl_replace_all_aux: \tl_gset:Nx }
+\cs_generate_variant:Nn \tl_replace_once:Nnn  { c }
+\cs_generate_variant:Nn \tl_greplace_once:Nnn { c }
+\cs_generate_variant:Nn \tl_replace_all:Nnn   { c }
+\cs_generate_variant:Nn \tl_greplace_all:Nnn  { c }
+\cs_new_protected:Npn \tl_replace_aux:NNNnn #1#2#3#4#5
   {
-    \cs_set_protected:Npx \tl_tmp:w ##1 #3 ##2 \q_stop
+    \tl_if_empty:nTF {#4}
+      {
+         \msg_kernel_error:nnx { tl } { empty-search-pattern }
+           { \tl_to_str:n {#5} }
+      }
       {
-        \exp_not:N \quark_if_no_value:nF {##2}
+        \cs_set:Npx \tl_tmp:w ##1##2 #4
           {
-            \tl_set:No \exp_not:N \l_tl_replace_tl { ##1 \exp_not:n{#4} }
-            \exp_not:n
-              {
-                \cs_set_protected:Npn \tl_tmp:w ##1 \q_nil #3 \q_no_value
-                  { \tl_put_right:No \l_tl_replace_tl {##1} }
-              }
-            \exp_not:n { \tl_tmp:w \prg_do_nothing: } ##2
-            \exp_not:n { #1 #2 \l_tl_replace_tl }
+            ##2
+            \exp_not:N \q_mark
+            \exp_not:N \use_none_delimit_by_q_stop:w
+            \exp_not:n { \exp_not:n {#5} }
+            ##1
+          }
+        #2 #3
+          {
+            \exp_after:wN #1
+            #3 \q_mark #4 \q_stop
           }
       }
-    \exp_after:wN \tl_tmp:w \exp_after:wN \prg_do_nothing:
-    #2 \q_nil #3 \q_no_value \q_stop
   }
-\cs_generate_variant:Nn \tl_replace_once:Nnn  { c }
-\cs_generate_variant:Nn \tl_greplace_once:Nnn { c }
-\cs_new_protected_nopar:Npn \tl_replace_all:Nnn
-  { \tl_replace_all_aux:NNnn \tl_set_eq:NN }
-\cs_new_protected_nopar:Npn \tl_greplace_all:Nnn
-  { \tl_replace_all_aux:NNnn \tl_gset_eq:NN }
-\cs_new_protected:Npn \tl_replace_all_aux:NNnn #1#2#3#4
-   {
-     \tl_clear:N \l_tl_replace_tl
-     \cs_set_protected:Npx \tl_tmp:w ##1 #3 ##2 \q_stop
-       {
-         \exp_not:N \quark_if_no_value:nTF {##2}
-           {
-             \exp_not:n
-               {
-                 \cs_set_protected:Npn \tl_tmp:w ##1 \q_nil ##2 \q_stop
-                   { \tl_put_right:No \l_tl_replace_tl {##1} }
-               }
-             \exp_not:N \tl_tmp:w ##1 \exp_not:N \q_stop
-           }
-           {
-             \exp_not:n { \tl_put_right:No \l_tl_replace_tl }
-               { ##1 \exp_not:n{#4} }
-             \exp_not:n { \tl_tmp:w \prg_do_nothing: } ##2 \exp_not:N \q_stop
-           }
-       }
-     \exp_after:wN \tl_tmp:w \exp_after:wN \prg_do_nothing:
-     #2 \q_nil #3 \q_no_value \q_stop
-     #1 #2 \l_tl_replace_tl
-   }
-\cs_generate_variant:Nn \tl_replace_all:Nnn  { c }
-\cs_generate_variant:Nn \tl_greplace_all:Nnn { c }
+\cs_new:Npn \tl_replace_aux_ii:w #1 \q_mark #2 { \exp_not:o {#1} }
+\cs_new:Npn \tl_replace_all_aux:
+  {
+    \exp_after:wN \tl_replace_aux_ii:w
+    \tl_tmp:w \tl_replace_all_aux: \prg_do_nothing:
+  }
+\cs_new_nopar:Npn \tl_replace_once_aux:
+  {
+    \exp_after:wN \tl_replace_aux_ii:w
+    \tl_tmp:w { \tl_replace_once_aux_end:w \prg_do_nothing: } \prg_do_nothing:
+  }
+\cs_new:Npn \tl_replace_once_aux_end:w #1 \q_mark #2 \q_stop
+  { \exp_not:o {#1} }
 \cs_new_protected_nopar:Npn \tl_remove_once:Nn #1#2
   { \tl_replace_once:Nnn #1 {#2} { } }
 \cs_new_protected_nopar:Npn \tl_gremove_once:Nn #1#2
@@ -310,26 +306,28 @@
 \cs_generate_variant:Nn \tl_if_empty:NT  { c }
 \cs_generate_variant:Nn \tl_if_empty:NF  { c }
 \cs_generate_variant:Nn \tl_if_empty:NTF { c }
-\prg_new_conditional:Npnn \tl_if_empty:n #1 { p,TF,T,F} {
-  \exp_after:wN \if_meaning:w \exp_after:wN \q_nil \tl_to_str:n {#1} \q_nil
-    \prg_return_true:
-  \else:
-    \prg_return_false:
-  \fi:
-}
+\prg_new_conditional:Npnn \tl_if_empty:n #1 { p , TF , T , F }
+  {
+    \exp_after:wN \if_meaning:w \exp_after:wN \q_nil \tl_to_str:n {#1} \q_nil
+      \prg_return_true:
+    \else:
+      \prg_return_false:
+    \fi:
+  }
 \cs_generate_variant:Nn \tl_if_empty_p:n { V }
 \cs_generate_variant:Nn \tl_if_empty:nTF { V }
 \cs_generate_variant:Nn \tl_if_empty:nT  { V }
 \cs_generate_variant:Nn \tl_if_empty:nF  { V }
-\cs_new:Npn \tl_if_empty_return:o #1 {
-  \exp_after:wN \if_meaning:w \exp_after:wN \q_nil
-          \tl_to_str:n \exp_after:wN {#1} \q_nil
-    \prg_return_true:
-  \else:
-    \prg_return_false:
-  \fi:
-}
-\prg_new_conditional:Npnn \tl_if_empty:o #1 { p,TF,T,F}
+\cs_new:Npn \tl_if_empty_return:o #1
+  {
+    \exp_after:wN \if_meaning:w \exp_after:wN \q_nil
+      \tl_to_str:n \exp_after:wN {#1} \q_nil
+      \prg_return_true:
+    \else:
+      \prg_return_false:
+    \fi:
+  }
+\prg_new_conditional:Npnn \tl_if_empty:o #1 { p , TF , T , F }
   { \tl_if_empty_return:o {#1} }
 \prg_new_conditional:Npnn \tl_if_eq:NN #1#2 { p , T , F , TF }
   {
@@ -379,20 +377,6 @@
 \cs_generate_variant:Nn \tl_if_in:nnT  { no }
 \cs_generate_variant:Nn \tl_if_in:nnF  { no }
 \cs_generate_variant:Nn \tl_if_in:nnTF { no }
-\prg_new_conditional:Npnn \tl_if_single:n #1 { p , T , F , TF }
-  {
-    \tl_if_blank:nTF {#1}
-      { \tl_if_empty:nTF {#1} { \prg_return_false: } { \prg_return_true: } }
-      { \tl_if_single_aux:n {#1} }
-  }
-\prg_new_conditional:Npnn \tl_if_single:N #1 { p , T , F , TF }
-  {
-    \tl_if_blank:oTF #1
-      { \tl_if_empty:NTF #1 { \prg_return_false: } { \prg_return_true: } }
-      { \exp_args:No \tl_if_single_aux:n {#1} }
-  }
-\cs_new:Npn \tl_if_single_aux:n #1
-  { \tl_if_empty_return:o { \use_none:n #1 } }
 \cs_new:Npn \tl_map_function:nN #1#2
   { \tl_map_function_aux:Nn #2 #1 \q_recursion_tail \q_recursion_stop }
 \cs_new_nopar:Npn \tl_map_function:NN #1#2
@@ -448,14 +432,9 @@
     \if_cs_exist:w #1 \cs_end:
       \cs:w #1 \exp_after:wN \cs_end:
     \else:
-      \exp_after:wN \tl_error_message:
+      \msg_expandable_error:n { Undefined~variable~name~'#1'! }
     \fi:
   }
-\group_begin:
-\tex_catcode:D `\! = 11 \scan_stop:
-\tex_catcode:D `\ = 11\scan_stop:%
-\cs_gset_nopar:Npn\tl_error_message:{\undefined variable name!}%
-\group_end:%
 \cs_new:Npn \tl_length:n #1
   {
     \int_eval:n
@@ -469,17 +448,14 @@
 \cs_new:Npn \tl_length_aux:n #1 { + 1 }
 \cs_generate_variant:Nn \tl_length:n { V , o }
 \cs_generate_variant:Nn \tl_length:N { c }
-\cs_new:Npn \tl_reverse:n #1
-  { \tl_reverse_aux:nN { } #1 \q_recursion_tail \q_recursion_stop }
-\cs_new:Npn \tl_reverse_aux:nN #1#2
+\cs_new:Npn \tl_reverse_items:n #1
+  { \tl_reverse_items_aux:nw #1 \q_recursion_tail \q_recursion_stop }
+\cs_new:Npn \tl_reverse_items_aux:nw #1 #2 \q_recursion_stop
   {
-    \quark_if_recursion_tail_stop_do:nn {#2} {#1}
-    \tl_reverse_aux:nN { #2 #1 }
+    \quark_if_recursion_tail_stop_do:nn {#1} { \use_none:n }
+    \tl_reverse_items_aux:nw #2 \q_recursion_stop
+    {#1}
   }
-\cs_generate_variant:Nn \tl_reverse:n {V,o}
-\cs_new_protected_nopar:Npn \tl_reverse:N #1
-  { \tl_set:Nf #1 { \tl_reverse:o { #1 \exp_stop_f: } } }
-\cs_generate_variant:Nn \tl_reverse:N { c }
 \cs_new:Npn \tl_trim_spaces:n #1
   {
     \etex_unexpanded:D \exp_after:wN \exp_after:wN \exp_after:wN
@@ -501,24 +477,32 @@
 \cs_new:Npn \tl_head:w #1#2 \q_stop {#1}
 \cs_new:Npn \tl_tail:w #1#2 \q_stop {#2}
 \cs_new:Npn \tl_head:n #1
-  { \tl_if_blank:nF {#1} { \tl_head:w #1 \q_stop } }
+  { \tl_head:w #1 { } \q_stop }
 \cs_new:Npn \tl_tail:n #1
-  { \tl_if_blank:nF {#1} { \tl_tail:w #1 \q_stop } }
+  { \tl_tail_aux:w #1 \q_mark { } \q_mark \q_stop }
+\cs_new:Npn \tl_tail_aux:w #1 #2 \q_mark #3 \q_stop { #2 }
 \cs_generate_variant:Nn \tl_head:n { V , v , f }
 \cs_generate_variant:Nn \tl_tail:n { V , v , f }
 \cs_new:Npn \str_head:n #1
   {
     \exp_after:wN \str_head_aux:w
     \tl_to_str:n {#1}
-    { \scan_stop: } ~ \q_stop
+    { { } } ~ \q_stop
   }
 \cs_new_nopar:Npn \str_head_aux:w #1 ~ %
   { \tl_head:w #1 { ~ } }
+\cs_new:Npn \str_tail:n #1
+  {
+    \exp_after:wN \str_tail_aux:w
+    \reverse_if:N \if_charcode:w
+        \scan_stop: \tl_to_str:n {#1} X X \q_stop
+  }
+\cs_new_nopar:Npn \str_tail_aux:w #1 X #2 \q_stop { \fi: #1 }
 \prg_new_conditional:Npnn \tl_if_head_eq_charcode:nN #1#2 { p , T , F , TF }
   {
     \if_charcode:w
         \exp_not:N #2
-        \str_if_eq:onTF { \use:n #1 ? } { #1 ? }
+        \tl_if_head_N_type:nTF { #1 ? }
           { \exp_after:wN \exp_not:N \tl_head:w #1 \q_nil \q_stop }
           { \str_head:n {#1} }
       \prg_return_true:
@@ -534,10 +518,10 @@
   {
     \if_catcode:w
         \exp_not:N #2
-        \str_if_eq:onTF { \use:n #1 ? } { #1 ? }
+        \tl_if_head_N_type:nTF { #1 ? }
           { \exp_after:wN \exp_not:N \tl_head:w #1 \q_nil \q_stop }
           {
-            \tl_if_head_begin_group:nTF {#1}
+            \tl_if_head_group:nTF {#1}
               { \c_group_begin_token }
               { \c_space_token }
           }
@@ -548,7 +532,7 @@
   }
 \prg_new_conditional:Npnn \tl_if_head_eq_meaning:nN #1#2 { p , T , F , TF }
   {
-    \str_if_eq:onTF { \use:n #1 ? } { #1 ? }
+    \tl_if_head_N_type:nTF { #1 ? }
       { \tl_if_head_eq_meaning_aux_normal:nN }
       { \tl_if_head_eq_meaning_aux_special:nN }
     {#1} #2
@@ -571,7 +555,7 @@
     \fi:
     {
       \if_catcode:w \exp_not:N #2
-                    \tl_if_head_begin_group:nTF {#1}
+                    \tl_if_head_group:nTF {#1}
                       { \c_group_begin_token }
                       { \c_space_token }
         \prg_return_true:
@@ -580,6 +564,42 @@
       \fi:
     }
   }
+\prg_new_conditional:Npnn \tl_if_head_N_type:n #1 { p , T , F , TF }
+  { \str_if_eq_return:on { \use:n #1 { } } { #1 { } } }
+\prg_new_conditional:Npnn \tl_if_head_group:n #1 { p , T , F , TF }
+  {
+    \if_predicate:w
+        \exp_after:wN \use_none:n
+          \exp_after:wN {
+            \exp_after:wN {
+              \token_to_str:N #1 ?
+            }
+            \c_false_bool
+          }
+          \c_true_bool
+      \prg_return_false:
+    \else:
+      \prg_return_true:
+    \fi:
+  }
+\prg_new_conditional:Npnn \tl_if_head_space:n #1 { p , T , F , TF }
+  {
+    \if_int_compare:w
+        \pdftex_strcmp:D
+          { }
+          { \tl_if_head_space_aux:w \prg_do_nothing: #1 ? ~ }
+        = \c_zero
+      \prg_return_true:
+    \else:
+      \prg_return_false:
+    \fi:
+  }
+\cs_new:Npn \tl_if_head_space_aux:w #1 ~ %
+  {
+    \exp_not:o {#1}
+    \if_false: { \fi: }
+    \exp_after:wN \use_none:n \exp_after:wN { \if_false: } \fi:
+  }
 \cs_new_protected:Npn \tl_show:N #1 { \cs_show:N #1 }
 \cs_generate_variant:Nn \tl_show:N { c }
 \cs_new_eq:NN \tl_show:n \etex_showtokens:D
@@ -590,51 +610,163 @@
 \tl_new:N \g_tmpb_tl
 \tl_new:N \l_tmpa_tl
 \tl_new:N \l_tmpb_tl
-\cs_new:Npn \tl_if_single_item:nTF #1
-  { \str_if_eq:onTF { \use_ii:nn #1 {?} ? } {??} }
-\cs_new:Npn \tl_if_single_item:nT #1
-  { \str_if_eq:onT { \use_ii:nn #1 {?} ? } {??} }
-\cs_new:Npn \tl_if_single_item:nF #1
-  { \str_if_eq:onF { \use_ii:nn #1 {?} ? } {??} }
-\cs_new:Npn \tl_if_single_item_p:n #1
-  { \str_if_eq_p:on { \use_ii:nn #1 {?} ? } {??} }
-\prg_new_conditional:Npnn \tl_if_head_begin_group:n #1 { p , T , F , TF }
-  {
-    \exp_after:wN \use_none:n
-      \exp_after:wN {
-        \exp_after:wN {
-          \token_to_str:N #1 .
-        }
-        \prg_return_true: \exp_after:wN \use_none:nn \token_to_str:N
-      }
+\cs_new:Npn \str_if_eq_return:on #1 #2
+  {
+    \if_int_compare:w
+        \pdftex_strcmp:D { \exp_not:o {#1} } { \exp_not:n {#2} }
+        = \c_zero
+      \prg_return_true:
+    \else:
       \prg_return_false:
+    \fi:
   }
-\prg_new_conditional:Npnn \tl_if_head_eq_space:n #1 { p , T , F , TF }
+\cs_new:Npn \tl_if_single_p:N { \exp_args:No \tl_if_single_p:n }
+\cs_new:Npn \tl_if_single:NT  { \exp_args:No \tl_if_single:nT  }
+\cs_new:Npn \tl_if_single:NF  { \exp_args:No \tl_if_single:nF  }
+\cs_new:Npn \tl_if_single:NTF { \exp_args:No \tl_if_single:nTF }
+\prg_new_conditional:Npnn \tl_if_single:n #1 { p , T , F , TF }
+  { \str_if_eq_return:on { \use_none:nn #1 ?? } {?} }
+\prg_new_conditional:Npnn \tl_if_single_token:n #1 { p , T , F , TF }
   {
-    \if_false: { \fi:
-      \tl_if_head_eq_space_aux:w \prg_do_nothing: #1 ? ~ }
+    \tl_if_head_N_type:nTF {#1}
+      { \str_if_eq_return:on { \use_none:n #1 } { } }
+      { \str_if_eq_return:on { ~ } { #1 } }
   }
-\cs_new:Npn \tl_if_head_eq_space_aux:w #1 ~ %
+\cs_new:Npn \tl_act:NNNnn { \tex_romannumeral:D \tl_act_aux:NNNnn }
+\cs_new:Npn \tl_act_aux:NNNnn #1 #2 #3 #4 #5
   {
-    \tl_if_empty_return:o { #1 }
-    \exp_after:wN \use_none:n \exp_after:wN { \if_false: } \fi:
+    \tl_act_loop:w #5 \q_tl_act_mark \q_tl_act_stop
+    {#4} #1 #2 #3
+    \tl_act_result:n { }
   }
-\prg_new_conditional:Npnn \tl_if_single_token:n #1 { p , T , F , TF }
+\cs_new:Npn \tl_act_loop:w #1 \q_tl_act_stop
   {
-    \tl_if_head_eq_space:nTF {#1}
+    \tl_if_head_N_type:nTF {#1}
+      { \tl_act_normal:NwnNNN }
       {
-        \str_if_eq:nnTF {#1} {~}
-          \prg_return_true: \prg_return_false:
+        \tl_if_head_group:nTF {#1}
+          { \tl_act_group:nwnNNN }
+          { \tl_act_space:wwnNNN }
       }
+    #1 \q_tl_act_stop
+  }
+\cs_new:Npn \tl_act_normal:NwnNNN #1 #2 \q_tl_act_stop #3#4
+  {
+    \if_meaning:w \q_tl_act_mark #1
+      \exp_after:wN \tl_act_end:wn
+    \fi:
+    #4 {#3} #1
+    \tl_act_loop:w #2 \q_tl_act_stop
+    {#3} #4
+  }
+\cs_new:Npn \tl_act_end:wn #1 \tl_act_result:n #2 { \c_zero #2 }
+\cs_new:Npn \tl_act_group:nwnNNN #1 #2 \q_tl_act_stop #3#4#5
+  {
+    #5 {#3} {#1}
+    \tl_act_loop:w #2 \q_tl_act_stop
+    {#3} #4 #5
+  }
+\exp_last_unbraced:NNo
+  \cs_new:Npn \tl_act_space:wwnNNN \c_space_tl #1 \q_tl_act_stop #2#3#4#5
+  {
+    #5 {#2}
+    \tl_act_loop:w #1 \q_tl_act_stop
+    {#2} #3 #4 #5
+  }
+\cs_new:Npn \tl_act_output:n #1 #2 \tl_act_result:n #3
+  { #2 \tl_act_result:n { #3 #1 } }
+\cs_new:Npn \tl_act_reverse_output:n #1 #2 \tl_act_result:n #3
+  { #2 \tl_act_result:n { #1 #3 } }
+\cs_new:Npn \tl_act_group_recurse:Nnn #1#2#3
+  {
+    \exp_args:Nf #1
+      { \exp_after:wN \exp_after:wN \exp_after:wN { #2 {#3} } }
+  }
+\cs_new:Npn \tl_reverse_tokens:n
+  {
+    \tex_romannumeral:D
+    \tl_act_aux:NNNnn
+      \tl_act_reverse_normal:nN
+      \tl_act_reverse_group:nn
+      \tl_act_reverse_space:n
+      { }
+  }
+\cs_new:Npn \tl_act_reverse_space:n #1
+  { \tl_act_reverse_output:n {~} }
+\cs_new:Npn \tl_act_reverse_normal:nN #1 #2
+  { \tl_act_reverse_output:n {#2} }
+\cs_new:Npn \tl_act_reverse_group:nn #1
+  {
+    \tl_act_group_recurse:Nnn
+      \tl_act_reverse_output:n
+      { \tl_reverse_tokens:n }
+  }
+\cs_new:Npn \tl_reverse:n
+  {
+    \tex_romannumeral:D
+    \tl_act_aux:NNNnn
+      \tl_act_reverse_normal:nN
+      \tl_act_reverse_group_preserve:nn
+      \tl_act_reverse_space:n
+      { }
+  }
+\cs_new:Npn \tl_act_reverse_group_preserve:nn #1 #2
+  { \tl_act_reverse_output:n { {#2} } }
+\cs_generate_variant:Nn \tl_reverse:n { o , V }
+\cs_new_protected_nopar:Npn \tl_reverse:N #1
+  { \tl_set:No #1 { \etex_unexpanded:D \tl_reverse:o { #1 { } } } }
+\cs_generate_variant:Nn \tl_reverse:N { c }
+\cs_new:Npn \tl_length_tokens:n #1
+  {
+    \int_eval:n
       {
-        \str_if_eq:onTF { \use_none:n #1 ? } {?}
-          {
-            \tl_if_head_begin_group:nTF {#1}
-              \prg_return_false: \prg_return_true:
-          }
-          \prg_return_false:
+        \tl_act_aux:NNNnn
+          \tl_act_length_normal:nN
+          \tl_act_length_group:nn
+          \tl_act_length_space:n
+          { }
+          {#1}
+      }
+  }
+\cs_new:Npn \tl_act_length_normal:nN #1 #2 { 1 + }
+\cs_new:Npn \tl_act_length_space:n #1 { 1 + }
+\cs_new:Npn \tl_act_length_group:nn #1 #2
+  { 2 + \tl_length_tokens:n {#2} + }
+\tl_const:Nn \c_tl_act_uppercase_tl
+  {
+    aA bB cC dD eE fF gG hH iI jJ kK lL mM
+    nN oO pP qQ rR sS tT uU vV wW xX yY zZ
+  }
+\tl_const:Nn \c_tl_act_lowercase_tl
+  {
+    Aa Bb Cc Dd Ee Ff Gg Hh Ii Jj Kk Ll Mm
+    Nn Oo Pp Qq Rr Ss Tt Uu Vv Ww Xx Yy Zz
+  }
+\cs_new:Npn \tl_expandable_uppercase:n
+  { \tex_romannumeral:D \tl_act_case_aux:nn { \c_tl_act_uppercase_tl } }
+\cs_new:Npn \tl_expandable_lowercase:n
+  { \tex_romannumeral:D \tl_act_case_aux:nn { \c_tl_act_lowercase_tl } }
+\cs_new:Npn \tl_act_case_aux:nn
+  {
+    \tl_act_aux:NNNnn
+      \tl_act_case_normal:nN
+      \tl_act_case_group:nn
+      \tl_act_case_space:n
+  }
+\cs_new:Npn \tl_act_case_space:n #1 { \tl_act_output:n {~} }
+\cs_new:Npn \tl_act_case_normal:nN #1 #2
+  {
+    \exp_args:Nf \tl_act_output:n
+      {
+        \exp_args:NNo \prg_case_str:nnn #2 {#1}
+          { \exp_stop_f: #2 }
       }
   }
+\cs_new:Npn \tl_act_case_group:nn #1 #2
+  {
+    \exp_after:wN \tl_act_output:n \exp_after:wN
+      { \exp_after:wN { \tex_romannumeral:D \tl_act_case_aux:nn {#1} {#2} } }
+  }
 \cs_new_protected:Npn \tl_new:Nn #1#2
   {
     \tl_new:N #1